The document provides guidelines for designing shield tunnel linings, including:
- The guidelines were developed by the ITA Working Group from 1993-1999 to promote advances in shield tunnel design.
- Key aspects of shield tunnel lining design covered include deciding loads, material properties, structural analysis methods, safety checking, and construction details. Numerical modeling and analytical methods are recommended for analyzing member forces in the lining.
The document discusses the design of precast segmental tunnel linings used for shield tunneling. It covers key aspects of segmental lining design including geometry, calculation of internal forces, reinforcement design, segment manufacture, waterproofing, and types of tunnel boring machines (TBMs) used for shield tunnel excavation.
NATM (New Austrian Tunneling Method ) in TunnelingHamed Zarei
1. NATM (New Austrian Tunneling Method) is a flexible tunneling method that utilizes shotcrete, wire mesh, rock bolts, and lattice girders for tunnel support. It mobilizes the strength of the rock mass and uses dynamic design that adapts the support based on rock conditions.
2. Excavation in NATM progresses from top heading to benches in poor rock. It is done in small sequential cells to support unstable ground. Primary lining of shotcrete is applied immediately after excavation.
3. Rock mass is classified using methods like RQD, RMR, and Q-factor to determine appropriate support. Flexible shotcrete and bolting allow adaptation to changing geology encountered during tunnel
tunnelling scope, construction techniques and necessityShashank Gaurav
This document discusses tunnel construction methods and planning. It describes the main types of tunnels based on application and construction method. The key construction methods covered are cut-and-cover, pipe jacking, shield tunneling, New Austrian tunneling method, and immersed tube tunneling. For each method, the document outlines the construction sequence, advantages, and disadvantages. Proper planning stages including investigations and alignment selection are also emphasized.
The document provides details on executing tunnel drives using the New Austrian Tunneling Method (NATM) in Manipur, India. It describes the various support elements of NATM including forepoling, drilling, blasting, mucking, shotcreting, installing wire mesh and lattice girders, and systematic rock bolting. A typical drive sequence is also outlined, beginning with forepoling installation and ending with rock bolting after two layers of shotcrete have been applied. The document emphasizes controlling deformation, stabilizing the surrounding rock mass, and providing flexible but active support during tunnel drives when using the NATM approach.
The document provides an overview of the New Austrian Tunneling Method (NATM). It discusses the history and definition of NATM, its broad principles which include mobilizing the strength of the surrounding rock mass, using shotcrete for protection, measurements and monitoring, and installing a primary lining. The procedure for NATM involves first shotcreting the excavated area for primary lining, adding wire mesh and lattice girders, installing rock bolts, and then applying a secondary shotcrete lining. 3D monitoring uses optical targets to accurately determine tunnel alignments and check for any displacements or incorrect alignments. NATM is currently being used widely on railway tunnel projects in Kashmir, India.
tunnel lining may be permanent or temporary based upon their use and requirement. design of lining is done in two parts one is temporary or initial lining design and other is permanent design of the lining. empirical and theoretical methods are major design methods.
Practices in Planning, Design and Construction of Head Race Tunnel of a Hydro...Mohit Shukla
This paper has been selected for oral presentation as well as inclusion in the conference proceedings of the ICCCGE 2016 : 18th International Conference on Civil,Construction and Geological Engineering held in Toronto, Canada during June,
13-14, 2016. This paper was also able to find a position in the international conference of Dams and Hydropower held at Laos in May 2016.
My publication Tunnels and Tunnelling magazineFilipe Mello
The document summarizes the construction of a crossover tunnel at the Fisher Street site for the Crossrail project in London. Key details include:
- The crossover tunnel allows trains to switch between the main eastbound and westbound running tunnels for maintenance or emergencies.
- Construction involved sprayed concrete lining (SCL) for the primary lining and cast-in-situ concrete for the secondary lining of the crossover tunnel and tunnel enlargements.
- Logistics were challenging due to the small site footprint in central London. Concrete delivery used boreholes from an adjacent disused tram tunnel to supply the tunnels.
- The secondary lining construction involved spraying a regulating layer, installing dowels and sprayed
The document discusses the design of precast segmental tunnel linings used for shield tunneling. It covers key aspects of segmental lining design including geometry, calculation of internal forces, reinforcement design, segment manufacture, waterproofing, and types of tunnel boring machines (TBMs) used for shield tunnel excavation.
NATM (New Austrian Tunneling Method ) in TunnelingHamed Zarei
1. NATM (New Austrian Tunneling Method) is a flexible tunneling method that utilizes shotcrete, wire mesh, rock bolts, and lattice girders for tunnel support. It mobilizes the strength of the rock mass and uses dynamic design that adapts the support based on rock conditions.
2. Excavation in NATM progresses from top heading to benches in poor rock. It is done in small sequential cells to support unstable ground. Primary lining of shotcrete is applied immediately after excavation.
3. Rock mass is classified using methods like RQD, RMR, and Q-factor to determine appropriate support. Flexible shotcrete and bolting allow adaptation to changing geology encountered during tunnel
tunnelling scope, construction techniques and necessityShashank Gaurav
This document discusses tunnel construction methods and planning. It describes the main types of tunnels based on application and construction method. The key construction methods covered are cut-and-cover, pipe jacking, shield tunneling, New Austrian tunneling method, and immersed tube tunneling. For each method, the document outlines the construction sequence, advantages, and disadvantages. Proper planning stages including investigations and alignment selection are also emphasized.
The document provides details on executing tunnel drives using the New Austrian Tunneling Method (NATM) in Manipur, India. It describes the various support elements of NATM including forepoling, drilling, blasting, mucking, shotcreting, installing wire mesh and lattice girders, and systematic rock bolting. A typical drive sequence is also outlined, beginning with forepoling installation and ending with rock bolting after two layers of shotcrete have been applied. The document emphasizes controlling deformation, stabilizing the surrounding rock mass, and providing flexible but active support during tunnel drives when using the NATM approach.
The document provides an overview of the New Austrian Tunneling Method (NATM). It discusses the history and definition of NATM, its broad principles which include mobilizing the strength of the surrounding rock mass, using shotcrete for protection, measurements and monitoring, and installing a primary lining. The procedure for NATM involves first shotcreting the excavated area for primary lining, adding wire mesh and lattice girders, installing rock bolts, and then applying a secondary shotcrete lining. 3D monitoring uses optical targets to accurately determine tunnel alignments and check for any displacements or incorrect alignments. NATM is currently being used widely on railway tunnel projects in Kashmir, India.
tunnel lining may be permanent or temporary based upon their use and requirement. design of lining is done in two parts one is temporary or initial lining design and other is permanent design of the lining. empirical and theoretical methods are major design methods.
Practices in Planning, Design and Construction of Head Race Tunnel of a Hydro...Mohit Shukla
This paper has been selected for oral presentation as well as inclusion in the conference proceedings of the ICCCGE 2016 : 18th International Conference on Civil,Construction and Geological Engineering held in Toronto, Canada during June,
13-14, 2016. This paper was also able to find a position in the international conference of Dams and Hydropower held at Laos in May 2016.
My publication Tunnels and Tunnelling magazineFilipe Mello
The document summarizes the construction of a crossover tunnel at the Fisher Street site for the Crossrail project in London. Key details include:
- The crossover tunnel allows trains to switch between the main eastbound and westbound running tunnels for maintenance or emergencies.
- Construction involved sprayed concrete lining (SCL) for the primary lining and cast-in-situ concrete for the secondary lining of the crossover tunnel and tunnel enlargements.
- Logistics were challenging due to the small site footprint in central London. Concrete delivery used boreholes from an adjacent disused tram tunnel to supply the tunnels.
- The secondary lining construction involved spraying a regulating layer, installing dowels and sprayed
Preliminary design for natm tunnel support in soilmukulkuriyal
1) The paper considers the design of tunnels constructed using the New Austrian Tunneling Method (NATM), where the tunnel is excavated using hand tools and immediately supported with shotcrete before a concrete liner is installed for long-term stability.
2) A finite element analysis is used to model NATM tunnel construction in undrained clays and develop a simplified method for preliminary design of shotcrete support based on soil properties, stress conditions, and stress release from excavation.
3) The method allows estimation of moments and thrusts on the concrete liner for typical conditions, with design values primarily dependent on soil deformation, initial stresses, and stress reduction from shotcreting.
The document provides information on the New Austrian Tunneling Method (NATM). It discusses the history and origins of NATM, highlighting its first use in Austria in the 1960s. The document also outlines the key principles and features of NATM, including mobilizing the strength of the rock mass, shotcrete protection, measurements, primary lining, closing the invert, rock mass classification, and dynamic design. The sequence of executing a tunnel using the NATM approach is also described.
The document provides an overview of the "Cut-and-Cover" and "Cover-and-Cut" tunnel construction techniques. The "Cut-and-Cover" method involves excavating a trench and constructing the tunnel structure within it, then refilling the trench. The "Cover-and-Cut" method first constructs a retaining concrete shell, then excavates underneath it for tunnel construction. Both methods are used for highway and railway tunnels where shallow depths or unstable ground conditions require extra support during construction. The document discusses the design process and construction steps for each method.
The document discusses the New Austrian Tunnelling Method (NATM) for excavating tunnels in weak rock. Some key points of the NATM include: (1) controlling ground deformations by applying early temporary support like rock bolts and shotcrete, (2) using flexible support that deforms with the ground, and (3) closing the tunnel invert quickly to form a load-bearing ring. The NATM also emphasizes monitoring ground movements and revising support as needed to maintain stability. While economical by matching support to conditions, the NATM requires cooperation between engineers to determine daily support requirements.
This document discusses tunneling and provides information on various topics related to tunnels. It introduces tunnels and their uses for transportation. It covers topics like lighting, ventilation, lining, size and shape of tunnels. It describes different types of tunnels and their applications. It also discusses advantages of tunnels and some limitations. In conclusion, it states that tunneling is effective for high traffic densities and has environmental benefits, but requires specialized expertise.
This document summarizes tunnelling projects and experiences in Greece from the early 1990s to present. It discusses the Athens Metro and use of microtunnelling and jet grouting to construct underground stations. It also describes the Egnatia Motorway project and challenges with Tunnel S3. Specifically, it examined over 100km of railway tunnels and nearly 350km of motorway and railway tunnels constructed. Lessons included using a Geological Strength Index and Tunnel Stability Factor to assess tunnel conditions. Jet grouting was used to improve weak rock and prevent face collapses during the Athens Metro project.
The document describes the cut and cover construction method used to build sections of a tunnel. It discusses (1) the reception area and sections built using diaphragm walls, soil nailing, and shotcrete; (2) the challenges of relocating utilities for the cut and cover sections; and (3) the process of excavating trenches, installing diaphragm walls, pouring concrete tunnel segments, and waterproofing. Cut and cover allows shallow tunnel sections to be constructed by excavating an open trench, installing structural supports, and then casting the tunnel structure.
The New Austrian Tunneling Method (NATM) involves:
1) Creating initial support on tunnel openings to prevent deterioration.
2) Excavating in short sections and applying shotcrete and metal supports.
3) Monitoring deformation with various instruments to ensure tunnel stability.
1) Tunnel boring machines (TBMs) are used to excavate tunnels with a circular cross-section through various ground types and diameters ranging from 1-20 meters.
2) A TBM consists of one or two large metal cylinder shields at the front, fitted with a cutting wheel, and hydraulic jacks that push the machine forward as it removes material.
3) TBMs allow for safer, more consistent tunneling compared to conventional methods and reduce risks from manual labor or explosives, though they require more supporting infrastructure and have higher costs.
This document discusses the challenges of tunnel design and construction in the GCC (Gulf Cooperation Council) region. It outlines several ongoing and future major tunneling projects in GCC countries like Qatar, Saudi Arabia, and Oman. Key challenges include weak rock formations, karstic features, high groundwater, and tight project timelines. Solutions proposed include using closed-face TBMs, detailed risk analysis to estimate machine advance rates, grouting programs for karst, and steel fiber-reinforced concrete tunnel linings to resist aggressive groundwater. Overall, the large scale of projects in challenging geotechnical conditions requires innovative design and construction approaches.
The document provides details about the construction of the underground Vasant Vihar Metro Station in Delhi. Key points include:
- The station is being constructed using the bottom-up method due to the hard rock strata. This involves excavation, constructing the base slab and then working upwards.
- Concrete grades M40 and M50 are being used for the slabs and columns respectively. Waterproofing involves priming with Master Seal M2525 and applying the waterproofing layer of Master Seal M800.
- Other aspects covered are borehole data analysis, structure layout, concreting operations, machinery used, and repair works. Precise construction methods are highlighted.
Tunnelling & underground design (Topic5-hard & weak rock tunnelling)Hamed Zarei
The document discusses different methods for excavating tunnels in rock, including drill-and-blast and mechanical excavation using tunnel boring machines (TBMs). Drill-and-blast involves drilling holes, loading them with explosives, and detonating them in a sequence according to a blast design. TBMs can excavate continuously using a rotating cutter head equipped with cutting tools. Factors that influence the performance of each method include rock properties, drilling/cutting rates, tool wear, and downtime. The goal is to optimize the energy used and fragmentation produced during excavation.
Shield Tail Deformations - Experiences, Mechanics and Lessonscoen_van_der_vliet
The document summarizes research into deformations experienced by the tail sections of two slurry shields used to construct a 6km road tunnel under a waterway. Measurements found deformations of up to 20mm in the shield tails after installation. Analysis determined the primary load carrying system of circumferential membrane forces was too weak, buckling under pressures around 10-16 bar. Recommendations included improving design models to account for gaps without soil support, using higher load factors for deformations, incorporating weaker details, and monitoring shield tails during construction to detect issues and enable recovery.
This document discusses rock tunnel engineering. It introduces different types of tunnels and their purposes. Tunnels can have various cross-sectional shapes and be located underground in different ground types. Tunnels are constructed using methods like cut-and-cover, drilling and blasting, or mechanized boring machines. Geotechnical investigations for tunnels are challenging due to uncertainties in ground conditions. Rock mass classification systems help characterize rock strength. The principles of tunnel stabilization and design aim to control ground movements rather than carry ground loads by mobilizing the strength of the surrounding ground.
This document provides terminology and descriptions related to underground structures like tunnels. It includes definitions of different tunnel construction elements and methods. Some key points covered include:
- Definitions of tunnel construction terms like adit, shaft, chamber, support, failure modes, and tunnelling methods.
- Descriptions of different tunnelling methods including shield tunnelling, cut-and-cover tunnelling, and tunnelling boring machines (TBMs).
- Factors that influence rock excavation for tunnels like geological structures, rock properties, and resistance to excavation.
- Examples of large irrigation tunnels including details of the Urfa Irrigation Tunnel in Turkey.
The document provides details about the construction of the CC-27 metro corridor project in Delhi. It discusses the proposed route, construction methods used at different stations, specifications of materials like concrete mixes, and repair works. The bottom-up construction approach is used at Vasant Vihar due to hard rock, while soft soil at Hauz Khas uses a top-down method. Waterproofing involves applying a two-component polyurethane coating after priming and adding aggregates to the primer layer.
The document discusses the design of pillars in underground coal mining. It notes that pillar failure can be gradual or sudden, with sudden failures causing disasters. Statutory guidelines exist for pillar dimensions but have limitations. The author proposes a modified formula to calculate pillar load that includes a dynamic load factor to account for loads during pillar extraction. Pillar strength is typically estimated using empirical formulas that the author critiques. The author suggests experience and site conditions be considered to better estimate pillar strength for ensuring stability of underground workings.
PPT on execution of 680 m long tunnel ensuring safety of the adjoining rail t...Rajesh Prasad
The said paper by Rajesh Prasad Executive Director RVNL has been published in IPWE international seminar held on 23/24-02-2018. The power point presentation nicely explains about how the technical challenges and administrative challenges addressed in completion of the tunnel while constructing a tunnel by the side of a railway tunnel with train operation in place and the entire area is affected by LWE activities.
The document discusses tunnel boring machines (TBMs) and their use in tunnel construction. It describes some of the key components of a TBM, including the tunnel lining process using precast concrete segments. It also discusses the importance of surveying activities to guide TBM operations and transfer control stations. Geotechnical considerations like rock quality designation are important for TBM tunneling. The main types of TBMs covered are slurry shield and earth pressure balance machines. Annulus grouts and mortars are also discussed for bonding segments and preventing issues during tunneling.
Effect of underground tunnelling by (TBM) on foundations of existing structuresKishor Ade
This document discusses a dissertation on the effect of underground tunnelling by tunnel boring machine (TBM) on existing structures' foundations. It introduces the topic, provides a literature review on previous related studies, and outlines the methodology, which involves finite element modeling and analysis of shallow and raft foundations at different tunnel depths using Midas GTS NX software. The results found that tunnelling was suitable for raft and shallow foundations on hard and soft murrum soils when the tunnel crown depth was 20-25m below foundations, as displacements did not exceed code limits. Tunnelling was not suitable under shadu soil foundations.
Strukturas General Presentation (200ppi)Strukturas
- Strukturas is a company founded in 1991 that specializes in turnkey bridge projects worldwide. They have experience dating back to the 1960s.
- They design, engineer, fabricate, and provide quality control for various types of bridge building equipment for cast in situ and precast concrete bridges.
- The document describes and provides images of different types of movable scaffolding systems, form travellers, launching gantries, segmental form travellers, full span launching methods, and beam launchers that Strukturas provides for efficient bridge construction.
The document discusses the New Austrian Tunnelling Method (NATM) and tunnel lighting. NATM involves using the tunnel lining to support loosened rock, prevent water percolation, and give tunnels their shape while withstanding soil pressures. Tunnel lighting is needed during and after construction, with electric lighting now being preferred over older methods like oil and gas lamps. Electric lighting provides steady, bright light without consuming oxygen or producing gases.
Preliminary design for natm tunnel support in soilmukulkuriyal
1) The paper considers the design of tunnels constructed using the New Austrian Tunneling Method (NATM), where the tunnel is excavated using hand tools and immediately supported with shotcrete before a concrete liner is installed for long-term stability.
2) A finite element analysis is used to model NATM tunnel construction in undrained clays and develop a simplified method for preliminary design of shotcrete support based on soil properties, stress conditions, and stress release from excavation.
3) The method allows estimation of moments and thrusts on the concrete liner for typical conditions, with design values primarily dependent on soil deformation, initial stresses, and stress reduction from shotcreting.
The document provides information on the New Austrian Tunneling Method (NATM). It discusses the history and origins of NATM, highlighting its first use in Austria in the 1960s. The document also outlines the key principles and features of NATM, including mobilizing the strength of the rock mass, shotcrete protection, measurements, primary lining, closing the invert, rock mass classification, and dynamic design. The sequence of executing a tunnel using the NATM approach is also described.
The document provides an overview of the "Cut-and-Cover" and "Cover-and-Cut" tunnel construction techniques. The "Cut-and-Cover" method involves excavating a trench and constructing the tunnel structure within it, then refilling the trench. The "Cover-and-Cut" method first constructs a retaining concrete shell, then excavates underneath it for tunnel construction. Both methods are used for highway and railway tunnels where shallow depths or unstable ground conditions require extra support during construction. The document discusses the design process and construction steps for each method.
The document discusses the New Austrian Tunnelling Method (NATM) for excavating tunnels in weak rock. Some key points of the NATM include: (1) controlling ground deformations by applying early temporary support like rock bolts and shotcrete, (2) using flexible support that deforms with the ground, and (3) closing the tunnel invert quickly to form a load-bearing ring. The NATM also emphasizes monitoring ground movements and revising support as needed to maintain stability. While economical by matching support to conditions, the NATM requires cooperation between engineers to determine daily support requirements.
This document discusses tunneling and provides information on various topics related to tunnels. It introduces tunnels and their uses for transportation. It covers topics like lighting, ventilation, lining, size and shape of tunnels. It describes different types of tunnels and their applications. It also discusses advantages of tunnels and some limitations. In conclusion, it states that tunneling is effective for high traffic densities and has environmental benefits, but requires specialized expertise.
This document summarizes tunnelling projects and experiences in Greece from the early 1990s to present. It discusses the Athens Metro and use of microtunnelling and jet grouting to construct underground stations. It also describes the Egnatia Motorway project and challenges with Tunnel S3. Specifically, it examined over 100km of railway tunnels and nearly 350km of motorway and railway tunnels constructed. Lessons included using a Geological Strength Index and Tunnel Stability Factor to assess tunnel conditions. Jet grouting was used to improve weak rock and prevent face collapses during the Athens Metro project.
The document describes the cut and cover construction method used to build sections of a tunnel. It discusses (1) the reception area and sections built using diaphragm walls, soil nailing, and shotcrete; (2) the challenges of relocating utilities for the cut and cover sections; and (3) the process of excavating trenches, installing diaphragm walls, pouring concrete tunnel segments, and waterproofing. Cut and cover allows shallow tunnel sections to be constructed by excavating an open trench, installing structural supports, and then casting the tunnel structure.
The New Austrian Tunneling Method (NATM) involves:
1) Creating initial support on tunnel openings to prevent deterioration.
2) Excavating in short sections and applying shotcrete and metal supports.
3) Monitoring deformation with various instruments to ensure tunnel stability.
1) Tunnel boring machines (TBMs) are used to excavate tunnels with a circular cross-section through various ground types and diameters ranging from 1-20 meters.
2) A TBM consists of one or two large metal cylinder shields at the front, fitted with a cutting wheel, and hydraulic jacks that push the machine forward as it removes material.
3) TBMs allow for safer, more consistent tunneling compared to conventional methods and reduce risks from manual labor or explosives, though they require more supporting infrastructure and have higher costs.
This document discusses the challenges of tunnel design and construction in the GCC (Gulf Cooperation Council) region. It outlines several ongoing and future major tunneling projects in GCC countries like Qatar, Saudi Arabia, and Oman. Key challenges include weak rock formations, karstic features, high groundwater, and tight project timelines. Solutions proposed include using closed-face TBMs, detailed risk analysis to estimate machine advance rates, grouting programs for karst, and steel fiber-reinforced concrete tunnel linings to resist aggressive groundwater. Overall, the large scale of projects in challenging geotechnical conditions requires innovative design and construction approaches.
The document provides details about the construction of the underground Vasant Vihar Metro Station in Delhi. Key points include:
- The station is being constructed using the bottom-up method due to the hard rock strata. This involves excavation, constructing the base slab and then working upwards.
- Concrete grades M40 and M50 are being used for the slabs and columns respectively. Waterproofing involves priming with Master Seal M2525 and applying the waterproofing layer of Master Seal M800.
- Other aspects covered are borehole data analysis, structure layout, concreting operations, machinery used, and repair works. Precise construction methods are highlighted.
Tunnelling & underground design (Topic5-hard & weak rock tunnelling)Hamed Zarei
The document discusses different methods for excavating tunnels in rock, including drill-and-blast and mechanical excavation using tunnel boring machines (TBMs). Drill-and-blast involves drilling holes, loading them with explosives, and detonating them in a sequence according to a blast design. TBMs can excavate continuously using a rotating cutter head equipped with cutting tools. Factors that influence the performance of each method include rock properties, drilling/cutting rates, tool wear, and downtime. The goal is to optimize the energy used and fragmentation produced during excavation.
Shield Tail Deformations - Experiences, Mechanics and Lessonscoen_van_der_vliet
The document summarizes research into deformations experienced by the tail sections of two slurry shields used to construct a 6km road tunnel under a waterway. Measurements found deformations of up to 20mm in the shield tails after installation. Analysis determined the primary load carrying system of circumferential membrane forces was too weak, buckling under pressures around 10-16 bar. Recommendations included improving design models to account for gaps without soil support, using higher load factors for deformations, incorporating weaker details, and monitoring shield tails during construction to detect issues and enable recovery.
This document discusses rock tunnel engineering. It introduces different types of tunnels and their purposes. Tunnels can have various cross-sectional shapes and be located underground in different ground types. Tunnels are constructed using methods like cut-and-cover, drilling and blasting, or mechanized boring machines. Geotechnical investigations for tunnels are challenging due to uncertainties in ground conditions. Rock mass classification systems help characterize rock strength. The principles of tunnel stabilization and design aim to control ground movements rather than carry ground loads by mobilizing the strength of the surrounding ground.
This document provides terminology and descriptions related to underground structures like tunnels. It includes definitions of different tunnel construction elements and methods. Some key points covered include:
- Definitions of tunnel construction terms like adit, shaft, chamber, support, failure modes, and tunnelling methods.
- Descriptions of different tunnelling methods including shield tunnelling, cut-and-cover tunnelling, and tunnelling boring machines (TBMs).
- Factors that influence rock excavation for tunnels like geological structures, rock properties, and resistance to excavation.
- Examples of large irrigation tunnels including details of the Urfa Irrigation Tunnel in Turkey.
The document provides details about the construction of the CC-27 metro corridor project in Delhi. It discusses the proposed route, construction methods used at different stations, specifications of materials like concrete mixes, and repair works. The bottom-up construction approach is used at Vasant Vihar due to hard rock, while soft soil at Hauz Khas uses a top-down method. Waterproofing involves applying a two-component polyurethane coating after priming and adding aggregates to the primer layer.
The document discusses the design of pillars in underground coal mining. It notes that pillar failure can be gradual or sudden, with sudden failures causing disasters. Statutory guidelines exist for pillar dimensions but have limitations. The author proposes a modified formula to calculate pillar load that includes a dynamic load factor to account for loads during pillar extraction. Pillar strength is typically estimated using empirical formulas that the author critiques. The author suggests experience and site conditions be considered to better estimate pillar strength for ensuring stability of underground workings.
PPT on execution of 680 m long tunnel ensuring safety of the adjoining rail t...Rajesh Prasad
The said paper by Rajesh Prasad Executive Director RVNL has been published in IPWE international seminar held on 23/24-02-2018. The power point presentation nicely explains about how the technical challenges and administrative challenges addressed in completion of the tunnel while constructing a tunnel by the side of a railway tunnel with train operation in place and the entire area is affected by LWE activities.
The document discusses tunnel boring machines (TBMs) and their use in tunnel construction. It describes some of the key components of a TBM, including the tunnel lining process using precast concrete segments. It also discusses the importance of surveying activities to guide TBM operations and transfer control stations. Geotechnical considerations like rock quality designation are important for TBM tunneling. The main types of TBMs covered are slurry shield and earth pressure balance machines. Annulus grouts and mortars are also discussed for bonding segments and preventing issues during tunneling.
Effect of underground tunnelling by (TBM) on foundations of existing structuresKishor Ade
This document discusses a dissertation on the effect of underground tunnelling by tunnel boring machine (TBM) on existing structures' foundations. It introduces the topic, provides a literature review on previous related studies, and outlines the methodology, which involves finite element modeling and analysis of shallow and raft foundations at different tunnel depths using Midas GTS NX software. The results found that tunnelling was suitable for raft and shallow foundations on hard and soft murrum soils when the tunnel crown depth was 20-25m below foundations, as displacements did not exceed code limits. Tunnelling was not suitable under shadu soil foundations.
Strukturas General Presentation (200ppi)Strukturas
- Strukturas is a company founded in 1991 that specializes in turnkey bridge projects worldwide. They have experience dating back to the 1960s.
- They design, engineer, fabricate, and provide quality control for various types of bridge building equipment for cast in situ and precast concrete bridges.
- The document describes and provides images of different types of movable scaffolding systems, form travellers, launching gantries, segmental form travellers, full span launching methods, and beam launchers that Strukturas provides for efficient bridge construction.
The document discusses the New Austrian Tunnelling Method (NATM) and tunnel lighting. NATM involves using the tunnel lining to support loosened rock, prevent water percolation, and give tunnels their shape while withstanding soil pressures. Tunnel lighting is needed during and after construction, with electric lighting now being preferred over older methods like oil and gas lamps. Electric lighting provides steady, bright light without consuming oxygen or producing gases.
The document discusses the construction of diaphragm walls. Diaphragm walls are reinforced concrete walls constructed underground using an excavation technique that keeps the trench full of a bentonite slurry. They are commonly used for deep basements and where construction time is limited. The construction process involves excavating trenches in panels, installing stop ends between panels, placing reinforcement cages, and pouring concrete through a tremie pipe to displace the slurry. Proper installation and maintenance of the bentonite slurry is crucial to prevent trench collapse during excavation and concrete placement.
This document provides an overview of bridge construction techniques, including:
- The main components of bridges such as the superstructure, bearings, substructure, piers, abutments, and foundation.
- Different types of bridges based on flexibility, form of superstructure, and materials used.
- Different foundation types including shallow foundations like spread and raft foundations, and deep foundations like piles, caissons, and wells.
- Techniques for constructing foundations including box caissons and open caissons.
The document describes an innovative precast system for bridge substructures for short spans and low volume bridges. The system uses precast concrete components including a cap, lagging, and footings connected by mechanical couplers and supported by H-piles embedded in the footings. It offers benefits over conventional cast-in-place systems like reduced construction time, less concrete and reinforcement needed, and easier installation with smaller equipment. The precast system was determined to be the preferred alternative described for replacing an existing timber bridge.
Join Ron Prychitko & Lorne Mielty for an overview of various Bridge-Plate, Multi-Plate and Tunnel Liner Plate applications. Through the presentation of various case studies they will cover product selection criteria for corrugated steel plate structures and best practices including assembly and installation.
Case study examples will include bridges, culverts, wildlife passes, mine portals, pedestrian tunnels and more.
What You’ll Learn:
-Learn about unique applications that solve demanding -problems
-Advantages of soil/steel structures
-Construction process for structures
-Available product, application and design resources
-General Canadian Codes and Standards will be referenced
Who Should Attend
-Bridge / Structural Engineers
-Municipal & Transportation Engineers
-Municipal, Provincial and Federal Infrastructure personnel
-Developers
-Earthworks & Highways Contractors
-Mining Engineers & Contractors
-Road Superintendents
Globalchimica produces chemical products for construction, mining, and tunneling. It has a research lab and quality control processes. Key products include:
- Fire resistant foams for cavity filling, waterproofing cracks, and consolidating rocks.
- Low viscosity resins for sealing cracks, bonding bolts, and consolidating unstable rock and soil. The resins cure quickly to load bolts.
- Technical and commercial support is provided through a partnership for tunneling and mining projects.
Dr. F. Dejahang discusses the benefits of precast concrete bridges, including lower initial costs than other bridge types, minimal required maintenance, and fast/easy construction. Precast bridges have assured quality from manufacturing in a controlled plant environment, are durable, attractive, and allow for minimal traffic disruption during construction as precast elements can be quickly installed. Bridge piers and decks can be constructed from precast concrete segments assembled on site. Erection gantries are used to lift and install large precast concrete segments for viaduct construction.
This document provides an overview of the setup and operations of a precast segmental casting yard for the Tukwila Link Light Rail Project. It describes the layout of the yard including areas for casting typical segments, pier segments, and balanced cantilever segments using matchcasting forms and rebar jigs. It also discusses the daily operations for casting different segment types and storing segments before shipping them to the construction site for erection.
Diaphragm wall: Construction and DesignUmer Farooq
The document discusses diaphragm walls, which are concrete or reinforced concrete walls constructed below ground using a slurry-supported trench method. Diaphragm walls can reach depths of 150 meters and widths of 0.5-1.5 meters. They are constructed using tremie installation or pre-cast concrete panels. Diaphragm walls are suitable for urban construction due to their quiet installation and lack of vibration. The document discusses different types of diaphragm walls based on materials and functions, and provides details on their design, construction process, and material requirements.
Top down construction is used in congested urban areas to minimize impacts on existing structures. It involves installing deep retaining walls and excavating from the top down in stages, allowing above-ground construction to progress simultaneously. This saves significant time over traditional bottom-up methods. Diaphragm walls are installed around the perimeter and intermediate barrette piles may be used for additional support. Concrete slabs are then cast with openings to allow further staged excavation from above until the final basement level is reached. Reinforcing is installed to connect each level during construction.
Areas related to circles - Area of sector and segment of a circle (Class 10 m...Let's Tute
Areas related to circles - Area of sector and segment of a circle (Class 10 maths).
Let's tute is an E-school or E- platform which is free for the student.Students will watch "MATHS" Videos for conceptual understanding.
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Collapse and consolidation Lung RadiologyNeelam Ashar
1) The document discusses mechanisms, patterns, and radiological signs of lung collapse and consolidation. It describes how collapse is diminished lung volume with reduced volume, while consolidation has normal lung volume with replacement of air.
2) Common patterns of lung collapse discussed include complete, lobar (right upper, middle, lower, left upper, lingula), and signs include fissure displacement, vascular changes. Consolidation causes opaque lung tissue and may show air bronchograms if airways are patent.
3) CT and ultrasound are also useful, with ultrasound showing echogenic consolidated lung tissue without normal air shadows. Key signs of specific lobar collapses and consolidations are described.
The document discusses different types of pavements used for highways. It describes flexible pavements which transmit wheel loads through grain-to-grain contact and consist of multiple layers including the surface course, binder course, base course, and sub-base course. Rigid pavements have sufficient strength to distribute loads over a wider area and typically consist of concrete over a single granular or stabilized layer. The document also covers pavement materials like soils, aggregates, and asphalt concrete and tests used to evaluate soil strength properties important for pavement design like the California Bearing Ratio test.
This document provides an overview of structural concrete design and structural systems for reinforced concrete buildings. It discusses the basic functions of building structural systems to support gravity and lateral loads. It also describes various types of loads and reinforced concrete structural systems, including different types of floor systems like flat plate, flat slab, and joist systems. Finally, it discusses common reinforced concrete structural members like beams, columns, slabs/plates, and walls/diaphragms.
Fast construction of bridges using precast concrete elements provides benefits to both owner agencies and contractors. For owners, it reduces the duration of work zones, lowering traffic handling costs and accident risks while causing less inconvenience to the public. Contractors benefit from reduced hazards, the ability to accomplish more work in less time with fewer weather delays, and lower costs. Examples are given of bridges constructed rapidly using precast concrete piles, pile caps, piers, abutments, beams, and other elements.
1. The document discusses various terminology used for underground structures related to excavation such as adits, tunnels, shafts, chambers, and portals.
2. It also discusses tunnel construction methods like shield tunneling and cut-and-cover tunneling as well as tunnel boring machines (TBMs).
3. Key challenges with underground excavations discussed include rock falls, rock bursts, squeezing ground, and ensuring long-term stability, especially in challenging ground conditions.
1. DPDK achieves high throughput packet processing on commodity hardware by reducing kernel overhead through techniques like polling, huge pages, and userspace drivers.
2. In Linux, packet processing involves expensive operations like system calls, interrupts, and data copying between kernel and userspace. DPDK avoids these by doing all packet processing in userspace.
3. DPDK uses techniques like isolating cores for packet I/O threads, lockless ring buffers, and NUMA awareness to further optimize performance. It can achieve throughput of over 14 million packets per second on 10GbE interfaces.
A Review Paper on Analysis and Design of Precast Box Culvert BridgeIRJET Journal
This document summarizes a research paper on the analysis and design of precast box culvert bridges. It begins with an abstract stating that box culverts are monolithic structures used to bridge roads and waterways. The document then reviews different types of IRC live load considerations for design, including Class 70R, Class A, and Class B loads. It discusses design considerations for box culverts like earth pressure effects, cushion depth, and structural elements to withstand bending moments and shear stresses. The methodology section outlines the steps used in modeling and analyzing a box culvert in STAAD Pro software. It also compares results for monolithically cast and separately cast top slabs. The conclusion states that box culverts are a robust, rigid
IRJET- Study of Response of Wall Type Pier for Varying Width of Superstru...IRJET Journal
This document presents a study on the seismic response of wall-type bridge piers with varying superstructure widths. Finite element models of piers were developed in MIDAS Civil for superstructure widths of 8m, 10m, 12.5m, and 16m. Response spectrum analysis was conducted according to Indian codes to obtain bending stresses, natural periods, and modal mass participation. Results showed natural periods decreased for the first two modes as width increased. Stresses also decreased with increasing width. Modal mass participation saw little change with varying width. In conclusion, wider superstructures led to improved seismic performance of wall-type piers.
IRJET- Effect of Pile Cap Thickness Variation on Load Carrying Capacity o...IRJET Journal
This document analyzes the effect of pile cap thickness variation on the load carrying capacity of piled foundations in a tall reinforced concrete building. A 56-story RC building is modeled in ETABS and its piled foundation is analyzed in SAFE. The analysis shows that increasing the pile cap thickness from 1m to 3m decreases the maximum settlement from 14.58mm to 9.31mm and decreases the differential settlement from 13.43mm to 8.34mm. However, increasing the pile cap thickness also increases the maximum positive and negative bending moments in the pile cap. The study concludes that increasing the pile cap thickness improves the load carrying capacity of the piled foundation by reducing settlements, but also increases bending stresses in the pile cap.
Deflection control in rcc beams by using mild steel strips (an experimental i...eSAT Publishing House
1) The document discusses an experimental investigation into using mild steel strips as a composite material with traditional reinforced concrete beams to help control deflection.
2) Three types of beams were tested - a control RCC beam, and two beams with mild steel strips embedded vertically along the sides in different configurations to increase stiffness.
3) Preliminary results found that deflection was reduced by about 30% and strength increased by about 25% in the composite beams compared to the control beam.
IRJET- Lateral Stiffness of Framed Structures for Lateral LoadsIRJET Journal
The document discusses methods for calculating the lateral stiffness of framed structures. It begins by noting the importance of evaluating stiffness for seismic design codes. Several approximate methods for calculating storey stiffness are compared, but accurate methods using finite element analysis have been less studied. The study aims to compare different accurate methods for calculating storey stiffness using analytical software models. A 4-storey reinforced concrete frame structure is modeled and different analysis methods are applied to calculate storey stiffnesses, including applying point loads at different locations and calculating drifts. Results will help identify the most accurate and practical method for engineers.
Evaluation of Design Provisions for One-Way Solid Slabs in SBC-304IRJET Journal
This study evaluates design provisions for one-way solid concrete slabs in the Saudi Building Code (SBC-304). The current code provisions for minimum slab thickness based on span-to-depth ratio do not consider parameters like live load, concrete strength, and steel yield strength. A parametric study is conducted considering these parameters to determine their effect on slab deflection. The results show that the current code provisions are very conservative and do not predict deflections accurately. Modified span-to-depth ratio relations are proposed based on the parametric study results, which include the effect of all parameters and allow more efficient slab designs while still controlling deflections.
Analysis Of Earthquake Resistant Structure By Base Isolation MethodIRJET Journal
1. The document discusses the analysis of earthquake-resistant structures using base isolation methods. Base isolation involves inserting seismic isolators at the base of a structure to decouple it from ground motions during an earthquake.
2. Several types of base isolators are discussed, including lead-rubber bearings, which provide rigidity under service loads and energy dissipation during seismic events.
3. A 10-story residential building is modeled using ETABS software to compare the seismic performance of a fixed-base structure versus one with base isolators. Results show that base isolation reduces story drift, displacement, and base shear, indicating less damage to the isolated structure.
COMPARATIVE STUDY OF DIFFERENT SHEAR WALL ON IRREGULAR STRUCTUREIRJET Journal
This document summarizes a study that compares the effects of different shear wall materials on an irregular high-rise building structure's earthquake resistance. Seven building models were analyzed: the original building plan, and plans with added shear walls of varying thickness of reinforced concrete or steel plate. Dynamic analysis using the response spectrum method was performed to determine story drift, time period, base shear, and other properties. The study found that increasing the thickness of steel plate shear walls decreases story drift and slightly reduces time period, while base shear is slightly reduced by thicker steel plate walls. Reinforced concrete wall thickness also impacts story drift and time period.
The document summarizes the planning, analysis, and design of a multispecialty hospital building. It includes the objectives to prepare architectural drawings, analyze the G+2 building using STAAD Pro, and design the building according to IS 456:2000 using the working stress method. It describes analyzing the building's ability to resist lateral loads. Maximum bending moments in beams and columns will depend on their relative rigidity. Structural elements like slabs, beams, columns, footings, and staircases will be designed according to code specifications using the working stress method.
Analysis and design of multi-storey building using staad.Progsharda123
This document presents a minor project report on the analysis and design of a four-storey building (ground plus three floors) using STAAD Pro software. It was submitted by five civil engineering students at Guru Nanak Dev Engineering College, Punjab, India in partial fulfillment of their Bachelor of Technology degree. The report covers various topics related to structural analysis and design including different analysis methods, design of building elements like slabs, beams, columns, and footings. It also discusses assumptions, design codes, loads, and materials used for the building design.
IRJET- Study & Improvement of Design and Construction Methodology of Precast ...IRJET Journal
The document studies the design and construction methodology of precast concrete segmental box culverts. It analyzes 6 alternative design modules for single and double box cells using different end conditions. Finite element analysis is conducted to determine the optimal section dimensions that result in minimum bending moments, shear forces, and principal stresses. Transportation cost is found to be lowest for a double box cell design with hinge joints at the top and bottom.
This document discusses a study on the effect of liquid additives on the strength and behavior of reinforced concrete model beams. Six model beams were tested with different proportions of high-range water reducing admixtures by weight of cement ranging from 0% to 2%. Compressive strength, modulus of elasticity, shear modulus, modulus of volume change, Poisson's ratio, deflection, and cracking were measured and calculated at 28 days. The best results were achieved using an admixture ratio of 1.6%, which improved compressive strength and modulus of elasticity but had no effect on cracking behavior. Control cube specimens were also tested to determine compressive strength at 7 and 28 days. The experimental results are presented in tables.
INVESTIGATION REPORT ON PRELIMINARY TESTS ON FAILURE OF STRUCTURE AND MONITORINGIRJET Journal
This document presents an investigation report on preliminary tests conducted to study structural failures and rehabilitation methods. Ten concrete beams were cast and tested under loading to study their failure modes. Three beams were kept as control specimens and tested up to ultimate failure. The remaining beams were cracked and then repaired using various methods like GFRP, jute fiber, and steel jacketing. After curing, the repaired beams were load tested to failure. The results found that steel jacketing was the most effective and economical rehabilitation method. Preliminary material tests were also conducted on cement, aggregates, and concrete to verify their properties.
IRJET- Study on Causes of Cracks and its Remedial Measures in Reinforced Conc...IRJET Journal
The document discusses cracks in reinforced concrete bridge piers and abutments. It first provides background on the causes of cracking, including applied loads, restraint from volume changes, and drying shrinkage. It then presents a case study of a bridge exhibiting cracks in the abutments and approaches. The cracks are thought to be caused by movement of the abutments due to issues with surrounding soils. The document outlines various remedial measures that could address abutment movement and cracking, such as soil grouting, concrete jacketing, and epoxy injection. It concludes that abutment movement must be addressed to prevent further deterioration of the bridge structure.
IMPROVING THE STRUCTURAL EFFICIENCY OF STEEL TRUSSES BY COMPARATIVE STUDYIRJET Journal
1) The document discusses analyzing the structural efficiency of different types of steel trusses (Warren, Patt and Howe) through modeling in STAAD Pro software.
2) A Warren truss bridge model is analyzed under dead load, live load, and seismic load conditions. Displacement over time is highest for the Warren truss.
3) Natural frequencies are calculated, with Warren and Patt trusses having higher frequencies than the Howe truss.
4) The Warren truss experiences the greatest displacement under seismic loads, while the Patt and Howe trusses displace less.
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This document describes a design procedure for prestressed concrete beams that aims to optimize the layout of ordinary reinforcement. The procedure is based on an analytical model that uses a unified approach to simulate the interaction between axial force, bending moment, and shear force in reinforced and prestressed concrete elements. The model assumes compressive and tensile stress fields in the concrete and reinforcement. It was validated against experimental test results and nonlinear finite element analyses. An example application of the full design procedure for a prestressed concrete bridge beam is also presented.
NONLINEAR BUCKLING ANALYSIS OF STIFFENED PLATEIRJET Journal
This document summarizes a research project that analyzed the nonlinear and linear buckling behavior of stiffened plates using finite element analysis software (ANSYS). Stiffened plates were modeled and analyzed with varying parameters like thickness, number of stiffeners, and loading conditions. Both linear and nonlinear analyses were performed. Experimental testing was also conducted to validate the ultimate strength results. The analyses showed that adding stiffeners increases the plate's strength and stiffness while using less material. Stiffened plates exhibited high strength-to-weight ratios and provided an economical structural solution.
IRJET- Experimental Study of Structural Behaviour of Double Skin Hollow –...IRJET Journal
This document summarizes an experimental study on the structural behavior of double skin hollow concrete filled steel tubular (DSH-CFST) columns under axial compressive loading. 36 specimens were tested with varying hollowness ratios. Test results showed that DSH-CFST columns can provide higher strength and ductility than solid CFST columns. Stress-strain curves and load-deformation curves were compared for different specimen types. The study found that DSH-CFST columns exhibited up to 77% higher compressive stresses than solid CFST columns. DSH-CFST columns also demonstrated improved ductility compared to solid CFST columns. The results provide information on optimizing the strength and structural performance of DSH-CFST columns
TIME DIVISION MULTIPLEXING TECHNIQUE FOR COMMUNICATION SYSTEMHODECEDSIET
Time Division Multiplexing (TDM) is a method of transmitting multiple signals over a single communication channel by dividing the signal into many segments, each having a very short duration of time. These time slots are then allocated to different data streams, allowing multiple signals to share the same transmission medium efficiently. TDM is widely used in telecommunications and data communication systems.
### How TDM Works
1. **Time Slots Allocation**: The core principle of TDM is to assign distinct time slots to each signal. During each time slot, the respective signal is transmitted, and then the process repeats cyclically. For example, if there are four signals to be transmitted, the TDM cycle will divide time into four slots, each assigned to one signal.
2. **Synchronization**: Synchronization is crucial in TDM systems to ensure that the signals are correctly aligned with their respective time slots. Both the transmitter and receiver must be synchronized to avoid any overlap or loss of data. This synchronization is typically maintained by a clock signal that ensures time slots are accurately aligned.
3. **Frame Structure**: TDM data is organized into frames, where each frame consists of a set of time slots. Each frame is repeated at regular intervals, ensuring continuous transmission of data streams. The frame structure helps in managing the data streams and maintaining the synchronization between the transmitter and receiver.
4. **Multiplexer and Demultiplexer**: At the transmitting end, a multiplexer combines multiple input signals into a single composite signal by assigning each signal to a specific time slot. At the receiving end, a demultiplexer separates the composite signal back into individual signals based on their respective time slots.
### Types of TDM
1. **Synchronous TDM**: In synchronous TDM, time slots are pre-assigned to each signal, regardless of whether the signal has data to transmit or not. This can lead to inefficiencies if some time slots remain empty due to the absence of data.
2. **Asynchronous TDM (or Statistical TDM)**: Asynchronous TDM addresses the inefficiencies of synchronous TDM by allocating time slots dynamically based on the presence of data. Time slots are assigned only when there is data to transmit, which optimizes the use of the communication channel.
### Applications of TDM
- **Telecommunications**: TDM is extensively used in telecommunication systems, such as in T1 and E1 lines, where multiple telephone calls are transmitted over a single line by assigning each call to a specific time slot.
- **Digital Audio and Video Broadcasting**: TDM is used in broadcasting systems to transmit multiple audio or video streams over a single channel, ensuring efficient use of bandwidth.
- **Computer Networks**: TDM is used in network protocols and systems to manage the transmission of data from multiple sources over a single network medium.
### Advantages of TDM
- **Efficient Use of Bandwidth**: TDM all
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
Literature Review Basics and Understanding Reference Management.pptxDr Ramhari Poudyal
Three-day training on academic research focuses on analytical tools at United Technical College, supported by the University Grant Commission, Nepal. 24-26 May 2024
Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapte...University of Maribor
Slides from talk presenting:
Aleš Zamuda: Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapter and Networking.
Presentation at IcETRAN 2024 session:
"Inter-Society Networking Panel GRSS/MTT-S/CIS
Panel Session: Promoting Connection and Cooperation"
IEEE Slovenia GRSS
IEEE Serbia and Montenegro MTT-S
IEEE Slovenia CIS
11TH INTERNATIONAL CONFERENCE ON ELECTRICAL, ELECTRONIC AND COMPUTING ENGINEERING
3-6 June 2024, Niš, Serbia
Harnessing WebAssembly for Real-time Stateless Streaming PipelinesChristina Lin
Traditionally, dealing with real-time data pipelines has involved significant overhead, even for straightforward tasks like data transformation or masking. However, in this talk, we’ll venture into the dynamic realm of WebAssembly (WASM) and discover how it can revolutionize the creation of stateless streaming pipelines within a Kafka (Redpanda) broker. These pipelines are adept at managing low-latency, high-data-volume scenarios.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
Understanding Inductive Bias in Machine LearningSUTEJAS
This presentation explores the concept of inductive bias in machine learning. It explains how algorithms come with built-in assumptions and preferences that guide the learning process. You'll learn about the different types of inductive bias and how they can impact the performance and generalizability of machine learning models.
The presentation also covers the positive and negative aspects of inductive bias, along with strategies for mitigating potential drawbacks. We'll explore examples of how bias manifests in algorithms like neural networks and decision trees.
By understanding inductive bias, you can gain valuable insights into how machine learning models work and make informed decisions when building and deploying them.
Redefining brain tumor segmentation: a cutting-edge convolutional neural netw...IJECEIAES
Medical image analysis has witnessed significant advancements with deep learning techniques. In the domain of brain tumor segmentation, the ability to
precisely delineate tumor boundaries from magnetic resonance imaging (MRI)
scans holds profound implications for diagnosis. This study presents an ensemble convolutional neural network (CNN) with transfer learning, integrating
the state-of-the-art Deeplabv3+ architecture with the ResNet18 backbone. The
model is rigorously trained and evaluated, exhibiting remarkable performance
metrics, including an impressive global accuracy of 99.286%, a high-class accuracy of 82.191%, a mean intersection over union (IoU) of 79.900%, a weighted
IoU of 98.620%, and a Boundary F1 (BF) score of 83.303%. Notably, a detailed comparative analysis with existing methods showcases the superiority of
our proposed model. These findings underscore the model’s competence in precise brain tumor localization, underscoring its potential to revolutionize medical
image analysis and enhance healthcare outcomes. This research paves the way
for future exploration and optimization of advanced CNN models in medical
imaging, emphasizing addressing false positives and resource efficiency.
2. Preface
These guidelines present the basic concepts of shield tunnel lining and do not
supersede relevant specifications of each country or each project. The aim of these
guidelines is to promote advances in the design of shield tunnels in accordance
with the objectives of ITA prescribed in SECTIONⅡof the Statutes of ITA.
The working to make these guidelines was started at the Working Group
Research meeting in Amsterdam in 1993. After much study, discussion and
investigation, they were completed on December,1999. These guidelines consists
of three parts. Part I describes the outline of procedure of design. Part II presents
the detailed design methods. Part III provides the references including examples
of design. There are various methods to design shield tunnel lining and these
guidelines gives no priority to a specified method. They introduce design methods
generally and widely. Usually, shield tunnel is excavated in soft ground, compared
to rock tunnel. The parameters of lining such as dimension and strength of
materials are subject to not only ground condition but also construction condition.
When actually designing tunnel lining, it is needed much experience and practice.
It is not expected that these guidelines would cover everything to design tunnel
lining, but it may be very helpful to design it. It is hoped that they will be
continuously improved with the progress of tunnelling technology.
I highly appreciate Monsieur Yann Leblais who led our study as Animateur,
Professor Andre Assis and Professor Z Eisenstein who guided our study as Tuteur
and Former Tuteur respectively, Herr Dr.Harald Wagner, Professor Teodor Iftimie,
Dr.Birger Schmidt, Signor Piergiogio Grasso who greatly contributed to this study,
and members of Research and Development Committees of Japan Tunnelling
Association chaired by Professor Toru Konda who made the draft of these
guidelines.
November 1999
Yoshihiro Hiro Takano, Vice-Animateur of Working Group Research
4. After planning works of tunnel, the lining of shield tunnel is designed with the
following sequence, as a rule.
1. Decisiopn of specification, code or standard for design works
Tunnel to be constructed should be designed with appropriate specification
standard, code or standard, which are indicated by persons in charge of project or
decided by discussion between designers and them.
2. Decision of inner dimension of tunnel
Inner diameter of tunnel to be designed should be decided in consideration of the
space which is demanded to tunnel. This space is decided by;
Construction gauge and car gauge in case of railway tunnel,
Traffic volume and number of lanes in case of road tunnel,
Discharge incase of water tunnel and sewer tunnel,
Kind of facilities and their dimension in case of common duct.
3. Decision of load conditions
The loads acting on lining are ground pressure such as earth pressure and water
pressure, dead load, reaction, surcharge and thrust force of shield jacks, e.t.c..
Designer should select the critical cases to design lining.
4. Decision of lining conditions
Designer should decide the lining condition such as dimension of lining
(thickness), strength and characteristics of materials and arrangement of
reinforcement, e.t.c..
5. Computation of member forces
Designer should compute member forces such as bending moment, axial force and
shear force of lining with appropriate models and design methods.
6. Check of safety
Designer should check the safety of lining against the computed member forces in
consideration of critical conditions of them.
7. Review
If designed lining is not safe against design loads, designer should change lining
5. condition and design lining again. And, if designed lining is safe but not
economical, designer should change lining condition and design lining again.
8. Approval of design
If designer judges that designed lining is safe, economical and optimum,
documents of design should be approved by persons in charge of project.
Figure 1 shows the flow chart to design tunnel lining.
The annex is a summarized schematic example of step by step design procedure.
6. Planning of Tunnel Project
Alignment Survey/Geology Function/Capacity
Plan/Profile to be given to Tunnel
Cross Section Specification/Code/Standard to be used
Inner Diameter
Load Condition Assumption of Lining Condition
(Thickness , e.t.c.)
Model to Compute Member Forces
Computation of Member Forces
Check of Safety of Lining
No
Safe and Economical
Yes No
Approval
Yes
Execution of Construction Works
Figure 1 Flow Chart to design Tunnel Lining
8. WORKING GROUP 2 “RESEARCH“
Recommended guidelines for design of shield tunnel lining.
Summarized schematic example of step by step design procedure.
STEP 1 DEFINE GEOMETRIC PARAMETERS
Alignment, excavation diameter, lining diameter, lining thickness, average
width of ring, segment system, joint connections.
STEP 2 DETERMINE GEOTECHNICAL DATA
Specific gravity, cohesion (unconfined and effective), friction angle
(unconfined and effective), modulus of elasticity, modulus of deformation,
Ko-Value.
STEP 3 SELECT CRITICAL SECTIONS
Influence of overburden, surface loads, water, adjacent structures.
STEP 4 DETERMINE MECHANICAL DATA OF TBM
Total thrust pressure, number of thrusts, number of pads, pad geometry,
grouting pressure, space for installation.
STEP 5 DEFINE MATERIAL PROPERTIES
Concrete class, compressive strength, modulus of elasticity, steel type,
tensile strength, gasket type, gasket width, elastic capacity, allowable gap.
STEP 6 DESIGN LOADS
6.1 Geostatical loads
Analyse load effects on lining segments and ground.
LOADING 1: Initial state of stress LOADING 2: Initial stress relief
Fig. 1: Loading Case 1 Fig. 2: Loading Case 2
9. LOADING 3:Excavation supported LOADING 4: Excavation supported
by shield by grouted segment
Fig. 3: Loading Case 3 Fig. 4: Loading Case 4
LOADING 5: Long term deformation
Fig. 5: Loading Case 5
6.2 Thrust Jacking loads
Analyse load effects distributed on segment types by thruster pads.
Fig. 6: Thruster pads distribution
10. 6.3 Trailer and other service loads
Including main bearing loads, divided by number of wheels.
Fig. 7: Trailer load distribution
6.4 Secondary grouting loads
Extending regular grout pressure.
Fig. 8: regular grout pressure
6.5 Dead load, storage and erection loads
Bending moment influence.
Fig. 9: Self weight of segments on stock
11. STEP 7 DESIGN MODEL
The three- dimensional condition has to be simulated by symbolic
computation into two dimensional conditions.
7.1 Analytical model
Using formulas in accordance with national standards and with
superposition of selected design loads.
Fig. 13: Design load - Assumption of TERZAGHI
7.2 Numerical model
Using Finite-Element programs with constitutive laws in accordance with
national standards to achieve stresses and strains under elasto-plastic
conditions, allowing simulation of detailed construction stages.
Fig. 14: FEM network configuration
STEP 8 COMPUTATIONAL RESULTS
Are represented in table format as normal and shear forces, bending
moments and deflections, defining the design loads and subsequently
reinforcement of the segments.
13. CONTENTS
Page
1. General 1
1.1 Scope of Application 1
1.2 Design Principle 1
1.3 Definition of Terms 1
1.4 Notation 3
2. Loads 5
2.1 Kinds of Loads 5
2.2 Ground Pressure 6
2.3 Water Pressure 8
2.4 Dead Load 11
2.5 Surcharge 11
2.6 Subgrade Reaction 11
2.7 Loads from Inside 12
2.8 Loads during Construction Stage 12
2.9 Effects of Earthquake 12
2.10 Other Loads 12
3. Materials 13
3.1 Modulus of Elasticity 13
3.2 Stress-Strain Curve 13
4. Safety Factors 14
5. Structural Calculation 15
5.1 Design Principles 15
5.2 Computation of Member Forces 15
5.2.1 Model for computation 15
5.2.2 Evaluation of Joints 21
5.3 How to check the safety of section 22
5.3.1 Limit state design method 22
5.3.2 Allowable stress design method 24
5.4 Structural Calculation of Joints 24
5.5 Check of safety against thrust force of shield jacks 25
6. Structural Details 25
6.1 Dimension & Shape of Segment 25
6.2 Measures against Leakage 25
6.3 Structural Details to handle Segments and grout Hole 26
6.4 Angle of Joint of Key-Segment 26
6.5 Tapered Segment 28
7. Production of Segments 28
7.1 Tolerance of dimension 28
7.2 Inspection 28
8. Secondary Lining 30
8.1 General 30
8.2 Thichness 30
8.3 Computation of Member Forces 30
14. 8.3.1 Bedded Frame Model 31
8.3.2 Elastic Equation Method 31
8.4 How to check the safety of section 31
15.
16. 1
1. General
1.1 Scope ofApplication
These guidelines provide general requirements for the design of segmental linings made of reinforced concrete, and
the secondary lining of shield tunnel constructed in very soft ground such as alluvial or diluvial layers. They can be
applied to the segmental lining of rock tunnel which is excavated in earth or soft rock by Tunnel Boring Machine
(TBM). The physical characteristics on soft ground are as follows, in general.
N≦50
E≒2.5×N≦125 MN/㎡
qu≒N/80≦0.6 MN/㎡ Equ.1.1.1
Where, N:N value given by the standard penetration test,
E: E elastic modulus of soil. and
qu:Unconfined compressive strength of soil
1.2 Design Principle
It is a design principle to examine the safety of lining of shield tunnel for its purpose of usage. The calculation
processes including the prerequisite of design, the assumption and the conception of design, and the design lifetime
should be expressed in the report, in which the tunnel lining is examined in terms of its safety.
1.3 Definition of Terms
The following terms are defined for general use in this recommendation.
Segment: Arc-shaped structural member for initial lining of shield tunnel; These guideline is intended for precast
concrete segment. (See Fig.1.3.1.)
Segmental lining: Tunnel lining constructed with segments; 1 ring of lining comprises some pieces of segments.
Segmental lining completed in shield: The segmental lining system that all of segments are assembled inside
shield and lining is completed inside shield
Enlarged segmental lining: The segmental lining system that all segments except key segment are assembled
inside shield and ,right after shield, key segment is inserted and lining is completed
Thickness: Thickness of lining of the cross section of tunnel
Width: Length of segment in longitudinal direction
Joint: Discontinuity in the lining and contact surface betweeen segments
Types of joints: Plain joints: - with connecting elements - straight steel bolts
-curved steel bolts
-reusable inclined steel bolts
-plastic or steel connector
- without connecting elements
- with guiding bars
Tongue and groove joints
Hinge joints: - with convex - concave faces
- with convex - convex faces
- with centering elements - steel rod link
- without centering elements
Pin joints
17. 2
Circumferential joint: joint between rings
Radial joint: joint between segments in longitudinal direction
Bolt for joints: Steel bolt to joint segments
Width
Outer Diameter of Segmental Lining
Rectangular Segment Tapered Segment
Trapezoid Segment Hexagon Segment
Width
Thickness
Flat Type Segment Box Type Segment
Fig.1.3.1 Type of Segment
18. 3
A B
Circumferential joint
Radial joint
Segment
Segment
A B
B-B Section A-ASection
Fig.1.3.2 Segmental Lining
In actual design and construction, lining makeup, segment shapes, joint and waterproofing details, and tolerances
should be selected for effective, reliable and rapid erection, considering the following.
1)Method and details of erection and erection equipment
2)Functional requirements of the tunnel, including lifetime and watertightness requirements
3)Ground and groundwater conditions, including seismic conditions
4)Usual construction practice in the location of the tunnel
1.4 Notation
The following notations are used in these guidelines.
t: Thickness
A:Area
E: Modulus of elasticity
I: Moment of inertia of area
EI: Flexural rigidity
M: Moment
N:Axial force
S: Shearing force
ζ: Ratio between the increment of moment transmitted through the adjacent segment at the joint and M
(1+ζ)M is transmitted through the segment. (1-ζ)M is transmitted through the joint.
D: Diameter of lining Dc: Diameter of centroid
Ro,Rc,Ri: Outer radius, radius of centroid and inner radius of the lining
γ,γ',γw,γc: weight of soil, submerged unit weight of soil, unit weight of water and unit weight of
concrete
19. 4
H: Overburden
γw×Hw: Groundwater pressure at crown of lining
po: Surcharge
W: Weight of lining per meter in longitudinal direction
pg: Dead Load
pe1: Vertical earth pressure at crown of lining
pw1: Vertical water pressure at crown of lining applied to the elastic equation method (See 5.2.)
qe1: Horizontal earth pressure at crown of lining
qw1: Horizontal water pressure at crown of lining applied to the elastic equation method (See 5.2.)
pe2: Vertical earth pressure at bottom of lining
pw2: Vertical water pressure at bottom of lining applied to the elastic equation method (See 5.2.)
qe2: Horizontal earth pressure at bottom of lining
qw2: Horizontal water pressure at bottom of lining applied to the elastic equation method (See 5.2.)
pw: Water pressure
Fw: buoyancy
λ: Coefficient of lateral earth pressure
k: Coefficient of subgrade reaction
δ: Displacement of lining
pk: Subgrade reaction/ la reaction/ Bettung
C: Cohesion of soil / La cohesion du sol / Kohaesion vom Boden
φ:Angle of internal friction of soil
f'ck: Nominal strength of Concrete (Characteristic Compressive Strength of Concrete)
fy:Yield Strength of steel
Es: Modulus of elasticity of steel
P0
γ,C,φ
Groundwater Table H
Hw γ’,C,φ
D Tunnel
Fig.1.5.1 Notation
20. 5
2. Loads
2.1 Kinds of Loads
The following loads should be considered in the design of lining.
The following loads must always be considered.
(1) Ground pressure
(2) Water pressure
(3) Dead Load
(4) Surcharge
(5) Subgrade Reaction
If necessary, the following loads should be considered.
(6) Loads from inside
(7) Loads during construction stage
(8) Effects of earthquake
Special loads
(9) Effects of adjacent tunnels
(10) Effects of settlement
(11) Other loads
21. 6
2.2 Ground pressure
The ground pressure should be determined in accordance with appropriate analysis. For example, the ground
pressure should act radially on lining or be divided into the vertical ground pressure and the horizontal ground
pressure. In the latter case, the vertical ground pressure at the tunnel crown should be a uniform load and ,as a
rule, should be equal to the overburden pressure, if the designed tunnel is a shouldow tunnel. If it is a deep tunnel,
the reduced earth pressure can be adopted in accordance with Terzaghi's formula (See Formula 2.2.1.),
Protodiaconov’formula or other formulae. The horizontal ground pressure should be the uniformly varying load
acting on the centroid of lining from the crown to the bottom. Its magnitude is defined as the vertical earth
pressure multiplied by the coefficient of lateral earth pressure. (See Fig.2.2.3(1).) It can be evaluated as the uniform
load or the uniformly varying load with the pentagon model. (See Fig.2.2.3(2) .) The value of coefficient of lateral
earth pressure to be used in the design calculation should be between the value of coefficient of lateral earth
pressure at rest and the one of coefficient of active lateral earth pressure. Designer should decide it in consideration
of relaxation and construction conditions.
Concerning the unit weight of soil for the calculation of earth pressure, the wet unit weight should be used for soil
above groundwater table and the submerged unit weight should be used for one below groundwater table.
Surcharge P0
G.L.
Stratum No.i γi
Groundwater Tabel Hi H
Hw Stratum No.j γ’j
Hj
Tunnel
Fig.2.2.1 Section of Tunnel and surrounding Ground
Pe1=P0+ΣγiHi+Σγ’jHj Equ.2.2.1
Where,
Po=Surcharge
γi=Unit weight of soil of Stratum No.i which is located above groundwater table
Hi=Thickness of Stratum No.i which is located above groundwater table
γ’j=Unit weight of soil of Stratum No.j which is located under groundwater table
Hj= Thickness of Stratum No.j which is located under groundwater table
H=ΣHi+ΣHj
23. 8
pe1
qe1
qe2
Where;
qe1=λ(pe1+γ×t/2) (if tunnel is located above groundwater table.)
qe1=λ(pe1+γ’×t/2) (if tunnel is located under groundwater table.)
qe2=λ{pe1+γ×(2Ro-t/2)} (if tunnel is located above groundwater table.)
qe2=λ{pe1+γ’×(2Ro-t/2)} (if tunnel is located under groundwater table.)
Fig.2.2.3 Ground Pressure acting on Lining (1)
pe1 pe1
qe1
qe qe
qe1
Where,
qe=(qe1+qe2)/2
Fig.2.2.3 Ground Pressure acting on Lining (2)
25. 10
2.3 Water pressure
As a rule, the water pressure acting on lining should be the hydrostatic pressure. The resultant of water pressure
acting on lining is the buoyancy. If the resultant of the vertical earth pressure at crown and the dead load is greater
than the buoyancy the difference betueen them acts as the vortical earth pressure at bottom (subgrade reaction). If
the buoyancy is greater than the resultant of the vertical earth pressure at crown and the dead load, the tunnel
would float.
Pw1
Rc
θ Pw given by Equ.2.3.1
Pw1=γwHw (Water pressure at tunnel crown)
Pw=Pw1+γwRc(1-cosθ) Equ. 2.3.1
Fig.2.3.1 Hydrostatic Pressure
26. 11
2.4 Dead Load
Dead load is vertical load acting along the centroid of the cross-section of tunnel and is calculated in accordance
with Equ.2.4.1
pg=W/(2πRc)
pg=γc×t (If the section is rectangular,)
Equ.2.4.1
2.5 Surcharge
The followings act on lining as the surcharge. They increase earth pressure actiong on lining.
Road trafic load,Railway trafic load,Weight of buildings
2.6 Subgrade Reaction
When we compute the member forces in the lining, we must determine the acting range, the magnitude and the
direction of the subgrade reaction. The subgrade reaction is divided into the reaction independent of the
displacement of ground such as pe2 (See Fig.2.6.1.) and the reaction dependent on the displacement of ground. It is
assumed that the latter subgrade reaction is proportional to the displacement of ground and its factor of
proportionality is defined as the coefficient of subgrade reaction. The value of this factor depends on the ground
stiffness and the dimension of lining (radius of lining), and the subgrade reaction is the product of the coefficient of
subgrade reaction and the displacement of lining which is decided by the ground stiffness and the rigidity of
segmental lining. The rigidity of segmental lining depends on the rigidly of segment, the number and type of joint. .
The bedded rigid frame model can evaluate the subgrade reaction as the spring force. (See Fig.2.2.3, Fig.2.6.2 and
Fig.5.2.3.)
In case the member forces are computed with the FEM, plain strain elements simulating ground are evaluated as
spring for subgrade reaction.
pe1
pg
pw
pe2
2rpe2+πr2γw=2rpe1+2πrpg
pe2=pe1+πpg-πrγw/2
Fig.2.6.1 Subgrade Reaction independent of the Displacement of Ground (pe2)
27. 12
90
Fig.2.6.2AModel of Subgrade Reaction
2.7 Loads from Inside
Load caused by facilities suspended from the ceiling of tunnel or inner water pressure should be investigated.
2.8 Loads during Construction Stage
The following loads acts on the lining during construction stage.
① Thrust force of shield jacks
When segments are produced, the strength of segment against the thrust force of shield jacks should be tested.
For the analysis of influence of shield jack forces to segments, designer should examine shear and bending
forces resulting from credible eccentricity, including cases of placement at the limit of tolerance.
② Loads during transportation and handling of segments
③ Pressure of backfill grouting
④ Load by operation of erector
⑤ Others
Dead load of backup carriages, jack force of segment reformer, torque of cutterhead
2.9 Effects of Earthquake
The static analysis such as the seismic deformation method or the seismic coefficient method, or the dynamic
analysis should be used for the seismic design. The seismic deformation method is usually adopted to investigate
the effect of earthquake to tunnels. Details should be presented apart from these guidelines.
2.10 Other Loads
If necessary, the effect of adjacent tunnels or effect of unequal settlement should be investigated.
28. 13
3. Materials
These guidelines are intended for the reinforced concrete segment as the material of initial lining and cast-in-place
concrete as the material of secondary lining. Japan Industrial Standard (JIS), Deutsche Industrie-Norm (DIN) and
American Concrete Institute (ACI) Standard specify the test methods of materials.
There may not be a cast-in-place inner lining. If the outer segmental lining is designed and constructed to meet
lifetime tunnel lining demands, then a one –pass lining is certainly permitted.
3.1 Modulus of Elasticity
Tab.3.1.1 shows the moduli of elasticity of concrete and steel, as a reference.
Tab.3.3.1 Modulus of Elasticity of Concrete and Steel
Nominal Strength
f' ck(MN/㎡)
18 24 30 40 50 60
Modulus of Elasticity of concrete
Ec (×104MN/㎡)
2.2 2.5 2.8 3.1 3.3 3.5
Modulus of Elasticity of Steel E s =210,000(MN/㎡)
Quotation from Standard Specification for Design and Construction of Concrete Structures issued by Japan Society
of Civil Engineers (JSCE)
3.2 Stress-Strain Curve
Fig.3.2.1 and 3.2.2 show the stress-strain curves of concrete and steel respectively.
σ’c
kf’’cd σ’c=kf’’cd
σ’c=kf’’cd(εc’/ε’co){2-(ε’/ε’co)} ε’co=0.002
ε’cu=0.0035
O ε’co ε’cu ε’c
Fig.3.2.1 Stress-Strain Curve of Concrete
σs
σs=fyd
fyd
σs=Esεs
O εy εs
Fig.3.2.2 stress-Strain Curve of Steel
29. 14
4. Safety Factors
The safety factors should be based on the ground loading and should be defined in accordance with the structural
requirements and codes, for example, national Standard Specification for Design and Construction of Concrete
Structures for each project. Construction procedure and performance should be linked with the safety factors. On
their application to the design computation, refer to “5.3 How to check the safety of section”. If tunnel is designed
as temporary structure, the safety factors can be modified.
30. 15
5. Structural Calculation
SI unit should be used in the structural calculation of lining.
5.1 Design Principles
The design calculation of cross section of tunnel should be done for the following critical sections. (See Fig.5.1.1.)
① Section with the deepest overburden
② Section with the shouldowest overburden
③ Section with the highest groundwater table
④ Section with the lowest groundwater table
⑤ Section with large surcharge
⑥ Section with eccentric loads
⑦ Section with unlevel surface
⑧ Section with adjacent tunnel at present or planned one in the future
G.L.
Ground Water Table
Ground WaterTable
Case 1 Case 2 Case 3 Case 4
Surcharge
Tunnel in
the future
Case 5 Case 6 Case 7 Case 8
Fig.5.1.1 Critical Sections to be checked
5.2 Computation of Member Forces
The Member Forces (M,N,S) are calculated using various structural models.
5.2.1 Model for computation
The member forces should be computed with the following methods.
① Bedded frame model method (See Fig.s 5.2.1,2,3.)
31. 16
② Finite Element Method (FEM) (Fig.5.2.4.)
③ Elastic equation method (See Fig.5.2.5. and Tab.5.2.1.)
④ Schultze and Duddeck Model
⑤ Muir Wood Model
Refer to Fig.5.2.6.
The bedded frame model method is a method to compute member forces with matrix method using a computer
because this model is mutiple statically indeterminate. This method can evaluate the following conditions.
1) ununiformly varying load due to change of soil condition (See Fig.5.2.2(b).)
2) eccentric loads (See Fig.5.2.2(c).)
3) hydrostatic pressure (See "2.3 Water Pressure".)
4) spring force to simulate subgrade reaction (See "2.6 Subgrade Reaction".)
5) effect of joint by simulating joints as hinges or rotation springs (semi-hinge) (See “5.2.2 Evaluation of Joints”)
If the subgrade reaction against displacement due to dead load cannot be expected, the member forces caused by
dead load must be independently calculated and superposed with member forces caused by the other loads. In this
case, the member forces caused by dead load can be computed by the elastic equation method.
This method can adopt not only the subgrade reaction in normal direction but also the one in tangential direction.
The options on the range of the subgrade reaction are as follows.
① Full round-bedded model
② Bedded model without subgrade reaction at crown
③ Full round-non-tension bedded model
See Fig.5.2.3.
The FEM is based on the theory of continuous body and has been adopted with the developement of computer. In
the FEM, Young modulus and the Poisson's ratio of soil must be parameters. In the design by the FEM, segmental
lining is evaluated as beam element. The FEM can compute not only the member forces of tunnel lining but also
the displacement and stress-starin state of surrounding ground and the influence to overlying or adjacent
structures induced by tunnel construction.
The FEM model can reproduce the behavior of interaction of lining and massive ground realistically with the
following merits.
1) The behavior of massive ground can be evaluated in consideration of the initial state of stress of ground, the
parameters of ground such as Unit weight of soil, Young modulus and the Poisson’s ratio, the shape and size of
tunnel section and the execution method including its procedure.
2) The behavior of lining which resists the loads depends on the lining structure (number of segments, their
configuration and joint type, the characteristics of backfill grouting and their efficiency, and the loading given by
the ground. These factors can be evaluated.
3) The degree of relaxation which depends on the ground condition, the construction method such as the type of
shield method and backfill grouting method including the size of tail void can be evaluated.
The elastic equation method is a simple method to calculate member forces without a computer. But it cannot
evaluate the conditions of above-mentioned 1) to 5). (See Fig.5.2.5.)
In this method, water pressure should be evaluated as the combination of vertical uniform load and horizontally
uniformly varying load and horizontal subgrade reaction should be simplified as triangularly varying load. (See
Fig.2.2.4.)
32. 17
Pg Pg
Model (a) Model (b)
The subgrade reaction against displacement due to dead load can be evaluated in Model (a) and not evaluated in
Model (b).
Fig.5.2.1 Models for Bedded Frame Method to calculate Member Forces
Model (a)Adaptable Model (b)Adaptable Model (c)Adaptable
Fig.5.2.2Adaptable Loading Models for Bedded Frame Method
Model (a) Model (b) Model (c) Model (d)
Model Range of Bedding Direction of Bedding Bedding Compression/Tension
a Full round Normal Compression and tension
b Without crown Normal and tangential Compression and tension
c Without crown Normal Compression and tension
d Dependent on displacement Normal Compression only
Fig.5.2.3 Range and Direction of Subgrade Reaction of Calculation Model of Bedded Frame method
33. 18
P0
Fig.5.2.4 FEM Mesh Layout
Model (a)Adaptable Model (b) Unadaptable Model (c) Unadaptable
Fig.5.2.5 Loading Models for Elastic Equation Method to calculate Member Forces
34. 19
Table 5.2.1 Elastic Equations to compute Member Forces
Load Moment (M) (@Rc2) Axial Force (N) (@Rc) Shear Force (S) (`Rc)
Uniform load in
vertical direction
(P=pe1+pw1)
(1-2S2)@P/4 S2@P -SC@P
Uniform load in
lateral direction
(Q=qe1+qw1)
(1-2C2)@Q/4 C2@Q -SC@Q
Triangular
lyvarying load in
lateral direction
(Q’=qe2+qw2)
(Q-Q’)
(6-3C-12C2+4C3)@(Q-Q’)/48 (C+8C2-4C3)@(Q-Q’)/16 (S+8SC-4SC2)@(Q-Q’)/16
Subgrade
reaction in lateral
direction
(kδ)
0≦θ≦π/4
(0.2346-0.3536C)@ kδ
π/4≦θ≦π/2
(-0.3487+0.5S2+0.2357C3) @ kδ
0≦θ≦π/4
0.3536C@ kδ
π/4≦θ≦π/2
(-0.7071C+C2+0.7071S2C)@ kδ
0≦θ≦π/4
0.3536S@ kδ
π/4≦θ≦π/2
(SC-0.7071C2S) @kδ
Dead load
(g)
0≦θ≦π/2
{(3/8) π-θS-(5/6)C}@g
π/2≦θ≦π
{-π/8+(π-θ)S-(5/6)C-(1/2)πS2}
@g
0≦θ≦π/2
{θS-(1/6)C}@g
π/2≦θ≦π
{-πS+θS+πS2-(1/6)C}@g
0≦θ≦π/2
{θC-(1/6)S}@g
π/2≦θ≦π
{-( π - θ )C+ θ S+ π
SC-(1/6)S}@g
Lateral
displacement at
spring
(δ)
δ={(2P-Q-Q’)+πg}@Rc4/{24(ηEI/h+0.045k c4)
θ=Angle from crown
S=sinθ S2=sin2θ S3=sin3θ C=cosθ C2=cos2θ C3=cos3θ
S S
N M M N
36. 21
5.2.2 Evaluation of Joints
If the segmental lining is jointed with or without bolts, its actual flexural rigidity at joint is smaller than the
flexural rigidity of segment. (Structurally, segmental ring can be modeled as multiple hinged ring or lining having
the rigidity between perfectly uniform rigidity ring and multiple hinged ring.) If segments are staggered, the
moment at joint is smaller than the moment of the adjacent segment. The actual effect of joint should be evaluated
in the design.
M Ms
M Mj
Segment
M Ms
Ms=(1+ζ)M, Mj=(1-ζ)M
Fig.5.2.6 Distribution of Moment at Joint
37. 22
5.3 How to check the safety of section
According to the calculation result of member forces, the safety of the most critical sections must be checked with
the limit state design method or the allowable stress design method. They are shown, as follows.
① Section with the Maximum positive moment
② Section with the Maximum negative moment
③ Section with the maximum axial force
The safety of lining against the thrust force of shield jacks should be checked.
5.3.1 Limit state design method
The relationship between the design axial capacity and the design flexural capacity of member cross sections
subjected to axial load and flexural moment is described by the curve as shown in Fig.5.3.1. Therefore, as a rule,
the safety for combined axial load and flexural moment is examined by confirming that the point (Md, Nd) is
located inside of the (Mud, Nud) curve, that is, at the side of the origin as shown in Fig.5.3.1. (Mud, Nud) are
calculated by Equ.5.3.1 and Equ.5.3.2 respectively. On the stress-strain curve of cincrete and steel, refer to “3.4
Stress-Strain Curve”. In the Fig.5.3.1 and the equations 5.3.1 and 5.3.2, γb and γs are the safety factors of
concrete and steel.
38. 23
① Ultimate Limit State Ⅰ ε'u σc
ε'u=ε'l=ε'cu σs
Nud=Nmax, M=0 σs’
ε'l
Section Strain Stress
② Ultimate Limit State Ⅱ
ε'u=ε'cu, ε'l=0, x=t
Section Strain Stress
③ Ultimate Limit State Ⅲ
ε'u=ε'cu, ε'l<0, xo<x<t
Section Strain Stress
④ Ultimate Limit State Ⅳ
ε'u=ε'cu, ε'1<0, x=xo x
Nud=0
Section Strain Stress
Where, ε'u=Upper extreme fiber strain
ε'l=Lower extreme fiber strain
x=Distance between upper extreme fiber and neutral axis
N’ud Axial Capacity
N’ud=∫σ(y)bdy/γb+(Ts+T’s) /γs Equation 5.3.1
Integrate between –h/2 and h/2
Flexural Capacity
Mud=∫σ(y)ybdy/γb+{Ts(h/2-t)-T’s(h/2-t’)} /γs Equation 5.3.2
Integrate between –h/2 and h/2
Where, Ts=Asσs; Ts’=As’σs’
O
Mud
Fig.5.3.1 Transition of Ultimate Limit States and Mud-N'ud Diagram
39. 24
ε’c(y) kf’cd
t
εy σs
x h/2 σ’c(y)
y
M
N O h
-y
ε’y σs’
t’
Fig.5.3.2 State of Stress and Strain Distribution
5.3.2Allowable stress design method
If the extreme fiber stress of concrete and the stress of reinforcement are not more than the their allowable stresses,
the segmental lining should be safe against the design loads. (See Equations 5.3.3 and 5.3.4.)
σc≦σca=f’ck/Fc Equation 5.3.3
σs≦σsa=fyd/Fs Equation 5.3.4
Where,
σc:Extreme fiber stress of concrete
σca:Allowable stress of concrete
f’ck:Characteristic compressive strength (Nominal strength) of concrete
Fc :Safety factor of concrete
σs:Stress of reinforcement
σsa:Allowable stress of reinforcement
fyd:Yield stress of steel
Fs:Safety facror of steel
5.4 Structural Calculation of Joints
At joints, bolts are evaluated as reinforcement. The safety of joint should be checked by the same method as the one
to check the safety of segment described in "5.3 How to check the safety of section". As the locations of joints are
indefinite before the assembling of segments, the design calculation should be done for the three most critical
sections described in "5.3 How to check the safety of section".
If bolts are used for erection only and removed after erection, the joint should transmit a moment limited by the
normal force across the joint. Between rings, the force to be transferred from one ring to another is governed by
geometric interlock and the residual longitudinal force.
40. 25
5.5 Check of safety against thrust force of shield jacks
The safety of lining against the thrust force of shield jacks should be checked with the following equation, in the
minimum.
f’ck/Fc≧Fs/A
Where,
f’ck:Characteristic compressive strength (Nominal strength) of concrete
Fc :Safety factor of concrete
Fs:Total thrust force of shield jacks
A:Area of cross section area of lining
If more critical conditions are expected by the selection of used jacks, such cases should be checked because bending
moment is caused by it.
Microcracks of segment are propagated by the thrust force of shield jacks. They influence the longevity of
segmental lining. The quality control of tensile strength of concrete of segment should be considered to prevent the
increase of microcracks when segments are produced.
6. Structural Details
6.1 Dimension & Shape of Segment
The less the number of pieces of one segmental ring is, the better the efficiency to manufacture and assemble
segments. But, in consideration of their transportation and handling, the length of arc and the weight of one
segment should be determined.
6.2 Measures against Leakage
If the allowable leakage dischaege is designed, the drainage system can be instaled in the tunnel. If not, the
measures against leakage should be necessary. Watertightness requirements should be determined based on the
ultimate use and the functional requirements of the finished tunnel. An initial lining that is followed by a
cast-in-place inner lining ( whether or not a waterproofing membrane is applied) should be sufficiently tight to
permit the placement of inner lining without compromise to its quality. Then, sealing strips should be applied as
necessary. One-pass lining segments below the groundwater table should be furnished with one or two gaskets to
seal the tunnel. If only one gasket is used, then provisions should be made to place caulking in the event that
excessive leakage is expected.
(See Fig.6.2.1.)
The sealing method is divided into the gasket sealing and the paint sealing and the former is usually adopted. The
gasket sealing is to stick gasket on surface of joint of segment. The materials of gasket are butyl non-sulfide rubber,
deformation butyl rubber, solid rubber, special synthesis rubber and/or water- expansive material. Water-expansive
gasket is a compound of polymer which reacts with water and, natural rubber or urethane. If tunnel is excavated in
ground with high ground water pressure, two-line gasket should be stuck on joints of segments. In some cases,
butyl rubber is not sufficiently resilient to provide an adequate seal under significant external water pressure.
Then, it can be used as sealing strips in an initial segmental lining (which is followed by an inner lining.)
The caulking is the method that the groove which is made on inside-surface of segment is filed with the materials
of causing. The main chemicals of them are epoxy resin, thiokol and urea resin. The caulking should be executed
after rebolting of segment, cleanup of groove and painting of primer.
If leakage can not be stopped with the gasket sealing and the caulking, the urethane injection would be effective,
which is executed through holes to be made in segment, as urethane reacts with groundwater and is expanded.
If the quality of selected waterproofing system is not proven through the previous tests or construction records, its
system should be tested in the laboratory under the expected maximum pressure (with a suitable safety factor) and
41. 26
with joint geometry incorporating maximum permitted out-of-tolerance placement of segment at the joint. Where
groundwater is aggressive to components of the lining or components installed in the tunnel, full waterproofing
should be applied, including the use of waterproof concrete or external waterproofing of segments, or both. (For
example, salt groundwater or groundwater high chloride or sulphate content is aggressive to these components.)
Gasket
Segment
Caulking
Two-Gasket Sealing One-Gasket and Caulking
Fig.6.2.1 Gasket Sealing and Caulking
6.3 Structural Details to handle segments and grout
When segments are assembled with an erector, segment should have an equipment to handle and hang segment.
The lately developed vacuum type erector can handle segments without the above-mentioned equipment hanging a
segment.
If the backfill grouting is performed through segments, each segment should have a grout hole with the inner
diameter of about 50 mm to inject grout uniformly.Agrout hole can be used for the equipment hanging a segment.
6.4Angle of Joint of Key-Segment
The type of K-segment is divided into K-segment inserted in radial direction (Kr-Segment) and K-segment inserted
in longitudinal direction (Kl-segment). If this angle is too large, axial force acting on segment works as force to slide
joint..(See fig.6.4.1.)
Kl-segment can prevent the influence of axial force because its angle of joint is very small.
The design of the K-segment, if used, should consider the geometry of the erection system in the shield (and vice
versa).
42. 27
K-Segment
ωθk/2 θk
α
α=θk/2+ω (Both side-tapered K-segment)
α=θk+ω (One side-tapered K-segment) Equ.6.6.1
Where, α=Angle of joint of K-segment
θk=Central angle of K-segment
ω=Spare angle to insert K-segment(Usually, 2°≦ω≦5°)
Fig.6.4.1Angle of Joint of K-Segment
Direction of insert
A A
Segmental ring
B-Segmnet K-Segment B-Segment
Direction of shield drive
θk θk
Type-1 Type-2
A-ASection
Fig.6.4.2 Joint of K-Segment inserted in Longitudinal Direction
43. 28
6.5 Tapered Segment
Tapered segments are used for the construction of curved alignment or the direction control of shield. The
difference between the maximum width and the minimum width can be calculated with Equ.6.7.1.
δ={(m/n)S+S'}D/(R+D/2) Equ.6.7.1
Where, δ=difference between max.width and min.width of tapered segmental ring
S=Width of standard segmental ring
S'=Max.width of tapered segmental ring
m=Number of standard segmental rings in curved section
n=Number of tapered segmental rings in curved section
D=Outer diameter of tunnel
R=Radius of alignment at the center of tunnel
7. Production of Segments
7.1 Tolerance of dimension
The errors of dimension of produced segments should not be more than the tolerance. They should be minimize to
prevent lealkage and to assemble segments easily and accurately.
7.2 Inspection
The following inspections should be made for segment for the quality control of it. Fig.7.2.1 shows the sequence of
production of segment.
① Inspection of materials
② Inspection of appearance
③ Inspection of shape and dimension
④ Temporary assembly inspection of temporarily assembled segmental ring
⑤ Performance tests (Strength tests)
⑥ Other tests
44. 29
Forms
Inspection of Forms
Receipt of Materials Weighing Mixing Assembling of Reinforcements
Inspection of Materials Concrete Strength Test
High Pressure Curing
Concrete Placing Compaction Steam Curing Removal of Forms
Inspection ofAssembled Re-Bars
Inspection of temporarily
Assembled Segmental Ring
TemporaryAssembling
Curing Shipment
Inspection ofAppearance Strength Tests
Inspection of Shape and Dimension
Extract form Standard Specification for Design and Construction of Tunnelling issued by JSCE
Fig.7.2.1 Sequence of Manufacture of Segments
45. 30
8. Secondary Lining
8.1 General
Secondary lining is constructed with cast-in-place concrete. It is divided into non-structural member and structural
member. The former is executed to reinforce segments, to prevent corrosion and vibration, to improve appearance
of lining and to correct alignment. In the latter case, secondary lining is constructed as a structural member
combined with segmental lining.
8.2 Thichness
The thickness of secondary lining as a non-structural member usually ranges form 15 cm to 30 cm. The thickness
of secondary lining as a structural member is decided in accordance with the result of design calculation.
8.3 Computation of Member Forces
If secondary lining is constructed as a structural member, member forces of secondary lining should be computed
by using loads which act on lining after the completion of secondary lining. In this case, the tunnel lining combined
by the segmental lining and the secondary lining is divided into the double shell structure and the composite
structure in accordance with the smoothness of border between both linings. In case of the double shell structure,
only axial force must be transmitted through the border of both lining and shear force need not to be transmitted
through it. In case of the composite structure, both of axial force and shear force must be transmitted through the
border of both lining by dowelledly jointing both lining or making the surface of border uneven. As a rule, tunnel
lining combined by segmental lining and secondary lining should be treated as the double shell structure.
If secondary lining is a non-structural member, the design calculation of it can be omitted but, for safety, it might be
made by using dead load as load condition. If a waterproofing membrane without the drainage system is placed
before casting the secondary lining, the secondary lining should be designed for the full water pressure, as
maximum.
Assuming that tunnel lining combined by segmental lining and secondary lining is a double shell structure, the
member forces of secondary lining should be computed by any rational method that properly considers the
interaction between the initial lining and the secondary lining and is compatible with the design of the initial lining.
Examples of methods how to compute member forces are as follows.
46. 31
8.3.1 Bedded Frame Model Method
When the member forces of secondary lining are computed with the bedded frame model, the double ring frame
model should be used. In this model, the outer ring simulates the segmental lining and the inner ring simulates the
secondary lining. Fig.8.3.1 shows how to compute member forces of secondary lining with the bedded frame model.
○ : Hinged Joint ● :Rigid Joint
Double Shell Structure Composite Structure
Fig.8.3.1 Bedded Frame Model
8.3.2 Elastic Equation Method
Assuming that loads acting on lining are sustained by segmental lining and secondary lining in proportion to the
magnitude of the flexural rigidity. Equ.9.3.1 calculates the ratio between loads sustained by secondary lining and
total loads. When member forces of secondary lining are calculated, loads multiplied by μ replace corresponding
loads and EI1+EI2 replace EI in Tab.5.2.1.
μ=(E2I2/Rc2
4)/(E1I1/Rc1
4+ E2I2/Rc2
4) …………………………………………. Equ.9.3.1
8.4 How to check the safety of section
The safety of section should be checked with the limit state design method or the allowable stress design method ,
wchich are the same methods as used for the segmental lining.
47. PART III
REFERENCES
1.Design Example (1)
Refer to “Guidelines-Design Example-1.pdf”.
2.Design Example (2)
Refer to “Guidelines-Design Example-2.pdf”
3.References
48. REFERENCES
AFTES RECOMMANDATIONS RELATIVES A LA CONCEPTION, LE DIMMENTIONNEMENT ET
L’EXECUTION DES REVETEMENTS EN VOUSSOIRS PREFABLIQUES EN BETON ARME INSTALLES A
L’ARRIERE D’UN TUNNELIER (Recommendation published by French TunnellingAssociation (AFTES))
Specification of Shield Tunnelling for Design and Construction published by Japan Society of Civil Engineers
Ahrens, H., Lindner, E., Lux, K.H., 1982. Zur Dimensionierung von Tunnelausbauten nach den ,,Empfehlungen
zur Berechnung von Tunneln im Lockergestein (1980)". Die Bautechnik, nr.8, pp. 260 - 311.
Atkinson, J.H., Potts, D.M., 1978. Calculation of stresses and deformations around shouldow circular tunnels in
soft ground by the method of associated fields. Computer Methods in tunnel design. The Institution of Civil
Engineers, London, pp. 61 - 84.
Donovan, H.J., 1974. Expanded tunnel linings. Tunnels and Tunnelling. March.
Duddek, H. 1972. Zu den berechnungs methoden und Sicherheit von Tunnelbauten. Der Bauingenieur 47, pp. 44 -
52.
Duddeck, H.,Erdman, J. 1985. On Stuctural Design Models for Tunnels in Soft Soil. Underground Space, vol. 9, Nr.
5-6, pp. 246 - 253.
Fujita, K., Kusakabe, O. Editors. 1995. “Underground Construction in soft ground” Proc. Of the Int. Symp. On
Underground Construction in soft ground. New Delhi, India. Balkema, Roterdam.
T. Iftimie. 1998 Overview and a new hypothesis on earth pressure acting on circular tunnel lining. Proc. of
the world tunnel Congress '98 on Tunnels and Metropolises, Sao Paulo, Brasil, 25-30, April 1998.
(A.A.Balkema/Rotterdam/Brookfield 1998) vol.1, p. 267 - 272.
T. Iftimie. Roatesi S. 1996 The numerical modelling of the shield tunnelling method. Calibration with in situ
measurements. Comptes-rendue des Journees d'etudes Internationales A.F.T.E.S. (Specifique), Lyon, France,
21-24 Oct. 1996, p.39-47.
T. Iftimie. 1996 Acontribution to the concept and structural analysis of precast circular linings for shield driven
tunnels. Ph. D. Thesis, Bucharest, Romania.
T. Iftimie. 1994 Prefabricated Lining, Conceptional Analysis and Comparative Studies for Optimal
Solution. Proc. of the ITA International Congress Tunnelling and Ground Conditions
(A.A.Balkema/Rotterdam/Brookfield/1994),April 1994, Cairo, Egipt, p. 339 - 346.
T. Iftimie. 1992 Design consideration and testings in shield –driven tunnels. Proc. of the ITA International
Congress Towards New Worlds in Tunnelling, Acapulco, Mexic,16- 20 May,
(A.A.Balkema/Rotterdam/Brookfield/1994) p. 321 – 326.
I.T.A. - Working Group on general approaches to the design of tunnels, 1988. Guidelines for the disign of Tunnels.
49. Tunnelling and Underground Space Technology, nr.3, pp. 237 - 249.
Jansen, P. 1984. Tragverhalten von Tunelausbauten mit Gelenk Tubbings. Brauschweig Techn. Univ. Disertation.
Kastner, H. 1961. Statik des Tunnel und Stolenbaues. Springer - Verlag Berlin.
Lombardi, G., Amberg, W., 1979. L'Influence de la methode de construction sur l'equilibre final d'un tunnel.
Congres International de Mecanique des Roches. Montreaux , Suisse.
Muir - Wood,A.M. 1975. The circular tunnel in elastic ground. Geotechnique 25, nr. 1, p. 115 -127.
Orlov, S.A. 1961. Metodi staticeskogo rasciota tonnelei. Moscow. Gostroiisdat.
Pantet, A, 1991. Creusement de Galeries a faible profoundeur a l'aide d'un tunnelier a pression de boue. These.
Institut National des SciencesAppliquees de Lyon.
Rozsa, L. 1963. Die Bemessung Kreisformiger Tunnelwandungen aus prefabrizierten Stahlbetonelementen nach
dem Verfahren der Grenzbelastungen. Der Bauingenieur 36, Heft 11, p. 434 - 444.
Schulze, H., Duddek, H., 1964. Spannungen in schildvorgetrieben tunneln. Beton and Stahlbetonbau 8, p.169 -
175.
Sechy,K., 1970. TheArt of Tunneling. Akademiai Kiado, Budapest.
These guidelines are published in the Volume 15, Number 3, July-September of Tunnelling
and Underground Space Technology, the official journal of International Tunnelling
Association. All of copyrights including “Guidelines-Fig. 5.2.6.pdf”, “Guidelines-Design
Example-1.pdf” and “Guidelines-Design Example-2.pdf” are reserved by International
TunnellingAssociation.