Brief advice on some corrective measures to be used before and after crossing the ground or rock due to induced breakdown during the excavation phase of a tunnel in an urban area using the traditional NATM System or using a TBM EPB
The document discusses various theories and approaches for estimating loads and pressures on underground structures like tunnels. It describes how earth/rock pressures, water pressure, and loosening of rock masses can load tunnels. Several theories are explained that take different approaches to estimating vertical loads, lateral pressures, and bottom pressures on tunnels based on factors like depth, soil/rock properties, excavation method, and structural support. Key theorists discussed include Bierbäumer, Terzaghi, Tsimbaryevitch, and others and their formulas for calculating various pressure types on tunnels.
Soil dynamics deals with the behavior of soils subjected to changing loads over time, such as during earthquakes. The properties of soils in the top 20-30 meters below ground significantly influence how earthquake shaking propagates upward. While soil mechanics considers static loads, soil dynamics analyzes dynamic loads that vary over time, requiring consideration of properties like hysteretic behavior. Applications include machine foundations, geotechnical earthquake engineering, construction vibrations, subsurface characterization using seismic methods, offshore structures, traffic vibrations, and vibration control. Dynamic loads can be periodic, non-periodic, deterministic, non-deterministic, cyclic, or random like earthquake shaking.
The document provides a structural design post-mortem report for the Kampung Pulai Visitor Interpretive Centre project. It identifies issues with the existing building's structural components and proposes improvements. The summary discusses foundations, identifying bored pile foundation as the most suitable option. It is a deep foundation type that can extend into soil with sufficient bearing capacity without requiring excavation. Compared to driven piles, bored piles have lower risk of damage during installation and allow for precise length control. The report analyzes and compares different foundation types to propose the most stable, feasible and economical solution.
This document summarizes a study on modeling negative friction forces on pile foundations in loess soils prone to consolidation. It discusses European and Ukrainian design standards, previous research, and a case study modeling test pile behavior using PLAXIS 3D Foundation software. The study aims to clarify methods for incorporating negative skin friction forces resulting from soil consolidation, which can reduce pile capacity. Numerical modeling is seen as a way to better understand pile-soil interaction and deformation over time compared to physical testing alone.
This document contains the structural analysis of a two-storey bungalow located in Jakarta, Indonesia. It includes architectural plans of the ground floor, first floor, and roof. Structural plans show the structural layout and load distribution plans indicate how loads are transferred through the structure. Two beams and two columns were selected for individual analysis. Beam B-C/14a carries uniform loads which were calculated. Beam B/13-15 carries both uniform and point loads. The selected internal column B/13 and perimeter column C/13 were analyzed to determine their ultimate load capacities.
The document outlines key design criteria for high-rise buildings, including:
1. Limit states design philosophy to ensure structures can withstand worst case loads during construction and usage with an acceptable probability of failure.
2. Consideration of construction sequencing and methods to allow for rapid erection given the large capital costs of high-rise projects.
3. Accounting for all expected gravitational and lateral loads over the building's lifetime, including combinations of dead, live, wind and earthquake loads.
The document summarizes seismic damages from the 2001 Bhuj earthquake in India. It killed over 13,000 people and destroyed nearly 400,000 homes. Common failures of reinforced concrete structures included soft stories, floating columns, strong column weak beam configurations, mass and plan irregularities, poor construction materials and techniques, and pounding between adjacent buildings. Soft story failures occurred particularly in buildings with large ground floor openings. Floating columns and strong column weak beam designs led to column failures. Masonry structures commonly experienced out-of-plane wall failures, in-plane shear failures, connection failures between walls and floors, diaphragm failures, and failures around wall openings.
Lyapichev. Analysis, design & behavior of CFRDsYury Lyapichev
This document provides information on the analysis, design, behavior, and seismic resistance of concrete face rockfill dams (CFRDs). It discusses numerical modeling of CFRDs, stresses in the concrete face and underlying transition zones, and the effects of high compressibility of rockfill materials. It also summarizes general recommendations for dynamic analysis and design of high CFRDs in seismic regions, including use of roller compacted concrete to reduce concrete face deformation. A new design for the 275m high Kambarata-1 CFRD in Kyrgyzstan incorporates this technique to improve seismic safety.
The document discusses various theories and approaches for estimating loads and pressures on underground structures like tunnels. It describes how earth/rock pressures, water pressure, and loosening of rock masses can load tunnels. Several theories are explained that take different approaches to estimating vertical loads, lateral pressures, and bottom pressures on tunnels based on factors like depth, soil/rock properties, excavation method, and structural support. Key theorists discussed include Bierbäumer, Terzaghi, Tsimbaryevitch, and others and their formulas for calculating various pressure types on tunnels.
Soil dynamics deals with the behavior of soils subjected to changing loads over time, such as during earthquakes. The properties of soils in the top 20-30 meters below ground significantly influence how earthquake shaking propagates upward. While soil mechanics considers static loads, soil dynamics analyzes dynamic loads that vary over time, requiring consideration of properties like hysteretic behavior. Applications include machine foundations, geotechnical earthquake engineering, construction vibrations, subsurface characterization using seismic methods, offshore structures, traffic vibrations, and vibration control. Dynamic loads can be periodic, non-periodic, deterministic, non-deterministic, cyclic, or random like earthquake shaking.
The document provides a structural design post-mortem report for the Kampung Pulai Visitor Interpretive Centre project. It identifies issues with the existing building's structural components and proposes improvements. The summary discusses foundations, identifying bored pile foundation as the most suitable option. It is a deep foundation type that can extend into soil with sufficient bearing capacity without requiring excavation. Compared to driven piles, bored piles have lower risk of damage during installation and allow for precise length control. The report analyzes and compares different foundation types to propose the most stable, feasible and economical solution.
This document summarizes a study on modeling negative friction forces on pile foundations in loess soils prone to consolidation. It discusses European and Ukrainian design standards, previous research, and a case study modeling test pile behavior using PLAXIS 3D Foundation software. The study aims to clarify methods for incorporating negative skin friction forces resulting from soil consolidation, which can reduce pile capacity. Numerical modeling is seen as a way to better understand pile-soil interaction and deformation over time compared to physical testing alone.
This document contains the structural analysis of a two-storey bungalow located in Jakarta, Indonesia. It includes architectural plans of the ground floor, first floor, and roof. Structural plans show the structural layout and load distribution plans indicate how loads are transferred through the structure. Two beams and two columns were selected for individual analysis. Beam B-C/14a carries uniform loads which were calculated. Beam B/13-15 carries both uniform and point loads. The selected internal column B/13 and perimeter column C/13 were analyzed to determine their ultimate load capacities.
The document outlines key design criteria for high-rise buildings, including:
1. Limit states design philosophy to ensure structures can withstand worst case loads during construction and usage with an acceptable probability of failure.
2. Consideration of construction sequencing and methods to allow for rapid erection given the large capital costs of high-rise projects.
3. Accounting for all expected gravitational and lateral loads over the building's lifetime, including combinations of dead, live, wind and earthquake loads.
The document summarizes seismic damages from the 2001 Bhuj earthquake in India. It killed over 13,000 people and destroyed nearly 400,000 homes. Common failures of reinforced concrete structures included soft stories, floating columns, strong column weak beam configurations, mass and plan irregularities, poor construction materials and techniques, and pounding between adjacent buildings. Soft story failures occurred particularly in buildings with large ground floor openings. Floating columns and strong column weak beam designs led to column failures. Masonry structures commonly experienced out-of-plane wall failures, in-plane shear failures, connection failures between walls and floors, diaphragm failures, and failures around wall openings.
Lyapichev. Analysis, design & behavior of CFRDsYury Lyapichev
This document provides information on the analysis, design, behavior, and seismic resistance of concrete face rockfill dams (CFRDs). It discusses numerical modeling of CFRDs, stresses in the concrete face and underlying transition zones, and the effects of high compressibility of rockfill materials. It also summarizes general recommendations for dynamic analysis and design of high CFRDs in seismic regions, including use of roller compacted concrete to reduce concrete face deformation. A new design for the 275m high Kambarata-1 CFRD in Kyrgyzstan incorporates this technique to improve seismic safety.
This document discusses rockfall hazards and analysis. It begins with an introduction noting that rockfalls are a major hazard for mountainous transportation routes and have resulted in numerous deaths. It then discusses the mechanics of rockfalls, noting that slope geometry and surface materials are most important in determining rockfall trajectories. Various measures to reduce rockfall hazards are discussed, including identification of problems, reducing energy from excavation, installing physical barriers like nets and ditches, and the Rockfall Hazard Rating System used to assess slopes.
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 objective of this project is to calculate the factor of safety of a complex slope situation. The stress distribution zones are also shown in the project. The probability of slope failure can be shown using FLAC3D software.
Behaviour of Anchored Pile Wall Under Dynamic Load & EarthquakeIJERDJOURNAL
ABSTRACT:- The purpose of this study is to observe the behaviour of concrete pile wall that to be constructed in the Gazino Station of Ulus–Keçiören under the determined soil properties and site conditions, the studied area consisting existing four-storey building, excavation of two layers and supporting the pile wall with anchors, the water pressure is involved in this study and the ground water level is changeable to three levels, dynamic load to be applied and concentrated on the top of pile wall which will be subjected to earthquake on basement recorded by USGS in 1989.
Lyapichev. New RCC dams (Inter. Conf. on RCC, 2003)Yury Lyapichev
Seismic analyses of stress-strain state of new type of composed faced symmetrical hardfill dams with central zone of rockfill enriched with cement mortar of different heights & slopes are performed & compared with the traditional gravity RCC dams
This document summarizes key aspects of soil-structure interaction and its effects during seismic events. It discusses different soil types and their interaction with seismic waves, as well as soil liquefaction and remedial measures. It describes the two main types of soil-structure interaction: kinematic interaction due to foundation instability, and inertial interaction caused by soil deformation from structural forces. Detrimental effects can include increased natural period leading to resonance, and increased ductility demands. Past earthquakes demonstrated the importance of considering soil-structure response. Modeling methods include direct and substructure approaches. Eurocode 8 recognizes cases where soil-structure interaction must be considered.
Seismic Design of Buried Structures in PH and NZLawrence Galvez
This document discusses seismic design of buried rectangular structures according to Philippines and New Zealand design codes. It notes that buried structures generally perform better in earthquakes than above-ground structures due to less dynamic amplification effects. While the Mononobe-Okabe method is commonly used internationally for seismic design, the document argues this method has limitations and conservatisms. It reviews Philippines and New Zealand code requirements, which generally do not consider dynamic earth pressures for buried structures. The document proposes simplified seismic design approaches are needed to minimize conservatism for buried structures.
INFLUENCE OF SOIL-STRUCTURE INTERACTION ON RESPONSE OF A MULTI-STORIED BUILDI...SJ BASHA
This document discusses analyzing the influence of soil-structure interaction on the response of a multi-storied building to earthquake forces. It focuses on a 12-story building located in Amaravathi, India, which consists of different soil/rock profiles. Earthquake analysis is performed with the building resting on different soil types, and the fundamental time periods, base shears, and displacements are compared to a fixed base condition. The equivalent lateral force method and free vibration analysis are used to evaluate the structural response considering soil-structure interaction effects. Results are presented and conclusions are drawn regarding how soil properties influence seismic behavior.
Temporary Tie Backs in the Building Construction by Bill Morales MSc CCEBill Morales MSc
Temporary tieback walls were used to support deep excavations for a construction project with buildings surrounding the site. The project involved excavating an 18m by 4.5m pit in stages, with tied-back shotcrete walls on the south, west and east sides and a traditional wall on the north side. A total of 246 tiebacks were installed over 4 stages as excavation proceeded downwards. The tiebacks were designed for temporary support only and were later removed once construction was complete. The anchored walls successfully supported the excavation and adjacent buildings, including during a 6.5 magnitude earthquake during construction.
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.
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.
Transfer Slabs Beams Design Tall Building- تصميم بلا طات وجوائز التحويل الأب...Dr.Youssef Hammida
Transfer Slabs Beams Design Tall Building- تصميم بلا طات وجوائز التحويل الأبنية البرجية- Construction of Transfer Plate
It is the Slab / Beam from which picked up columns may be started where there are no columns underneath. So, it is a kindl of frame in which upper storey columns are directly supported over these slab and hence are cr... more abstract
The document discusses soil-structure interaction (SSI), which refers to how the motion of a structure influences the response of the soil and vice versa. It notes that SSI effects are more prominent for structures where piston-action effects are significant. The types of SSI are inertial, kinematic, and foundation deformation interactions. The degree of SSI influence depends on soil stiffness, structural properties, and dynamic characteristics. Two common analysis methods are the direct method using finite element modeling and the substructure method, which is more computationally efficient. Factors like soil compressibility and regional subsidence can affect SSI, with resonance effects also influencing seismic response due to SSI.
The document discusses the Torino Metro Line 1 project in Italy. It describes the general characteristics of the metro line including the tunnel dimensions, length, and stations. It then discusses several key aspects that had to be managed for the project, including the contract type, procurement of a tunnel boring machine, complex design process due to the urban environment, public opinion, legislative conditions, and environmental requirements. The geology of the tunnel route consisting of quaternary deposits is also summarized.
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.
1. The document examines the use of Tunnel Stability Factor (TSF) to estimate convergence and face stability in weak rock tunnels. TSF considers rock mass strength, overburden height, and tunnel size.
2. Parametric numerical analyses were conducted on 74 tunnels varying in size, depth, and rock mass quality. Dimensionless plots of plastic zone radius and convergence vs TSF showed good correlation despite varying conditions.
3. Guidelines for criticality of stability were developed based on convergence-to-radius ratio ranges associated with TSF levels, indicating severe squeezing for TSF < 0.2 and increased risk of collapse below 0.3 without support.
This document provides information about retaining walls. It defines retaining walls and their purpose to provide stability to natural terrain when slopes are modified. It describes the main types of retaining walls: gravity walls, cantilever walls, and counterfort walls. It also discusses the loads acting on retaining walls, including active earth pressure, passive earth pressure, self-weight, and surcharge loads. The document includes an example problem to calculate the factor of safety against sliding and overturning for a concrete gravity retaining wall.
- Soil-structure interaction (SSI) describes how the response of soil influences the motion of a structure, and vice versa, rather than having independent displacements.
- The three critical aspects of SSI are: 1) Inertia effects on base shear and moment, 2) How base shear relates to foundation/soil displacement, 3) How moment relates to foundation/soil rotation.
- The degree of SSI influence depends on soil stiffness, structure properties like period and damping, and structure stiffness and mass. SSI is more important for flexible structures on soft soil.
Auvinet exc foundations and geotechnical hazards cfpbolivia
The document provides an overview of geotechnical hazards and challenges for excavations and foundations in Mexico City, where the soft lacustrine clays are highly compressible and susceptible to subsidence. Three key points:
1) The subsoil of Mexico City can be divided into three zones (foothills, transition, lake) with the lake zone containing the most compressible clays. Subsidence rates in some areas exceed 1m per year due to groundwater extraction.
2) Excavations require lateral support systems like sheet piles, diaphragm walls, or precast walls due to the low shear strength of the clays. Design must consider failures of slopes, walls, or the excav
SOIL STRUCTURE INTERACTION STUDY ON PLANE BUILDING FRAME SUPPORTED ON PILE GR...IAEME Publication
Background/Objectives: The main objective of this work is to determine the soil interaction of a plane building frame underpinned by pile groups which are embedded in cohesive soil (clayey soil).Methods: The impact of Soil-Structure Interaction on response of a 4 storey framed Building underpinned by Pile group is reported in this paper. The four storey frame consists of three bays and columns of the frame supported by a pile group. The Pile group is presumed to be embedded in the Cohesive soil mass (clayey soil). The soil mass is represented by equivalent springs. The displacement of the building frame caused due to the deflection of the foundation with and without Soil Structure Interaction is analyzed using ANSYS. Findings: Soil non-linearity in lateral direction is indicated by the P-Y curve developed using Matlock equations. The soil properties which are used for clay (cohesive soil) are from the Triaxial Consolidated Undrained Compression Test on soil. Shear Force and Bending Moments at the base of the columns are determined for the frame which is analyzed with and without consideration of soil structure interaction.
Foaming and polymeric agents used in test for the conditioning of soils during the progress of excavation work for a tunnel with a mechanized shield of the TBM EPB type.
The Rion Antirion bridge in Greece connects the Peloponnese peninsula to the mainland across the Gulf of Corinth. Its foundations had to withstand severe environmental conditions including weak soils, earthquakes up to magnitude 7.0, and long-term tectonic movements. The innovative foundation concept adopted reinforced the natural ground with steel tubular piles and included a gravel layer between the piles and foundation raft. This provided capacity to resist the large seismic forces while minimizing differential settlement hazards. Extensive site investigations characterized the poor soil properties to ensure compatible design of seismic demand and foundation capacity.
This document discusses rockfall hazards and analysis. It begins with an introduction noting that rockfalls are a major hazard for mountainous transportation routes and have resulted in numerous deaths. It then discusses the mechanics of rockfalls, noting that slope geometry and surface materials are most important in determining rockfall trajectories. Various measures to reduce rockfall hazards are discussed, including identification of problems, reducing energy from excavation, installing physical barriers like nets and ditches, and the Rockfall Hazard Rating System used to assess slopes.
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 objective of this project is to calculate the factor of safety of a complex slope situation. The stress distribution zones are also shown in the project. The probability of slope failure can be shown using FLAC3D software.
Behaviour of Anchored Pile Wall Under Dynamic Load & EarthquakeIJERDJOURNAL
ABSTRACT:- The purpose of this study is to observe the behaviour of concrete pile wall that to be constructed in the Gazino Station of Ulus–Keçiören under the determined soil properties and site conditions, the studied area consisting existing four-storey building, excavation of two layers and supporting the pile wall with anchors, the water pressure is involved in this study and the ground water level is changeable to three levels, dynamic load to be applied and concentrated on the top of pile wall which will be subjected to earthquake on basement recorded by USGS in 1989.
Lyapichev. New RCC dams (Inter. Conf. on RCC, 2003)Yury Lyapichev
Seismic analyses of stress-strain state of new type of composed faced symmetrical hardfill dams with central zone of rockfill enriched with cement mortar of different heights & slopes are performed & compared with the traditional gravity RCC dams
This document summarizes key aspects of soil-structure interaction and its effects during seismic events. It discusses different soil types and their interaction with seismic waves, as well as soil liquefaction and remedial measures. It describes the two main types of soil-structure interaction: kinematic interaction due to foundation instability, and inertial interaction caused by soil deformation from structural forces. Detrimental effects can include increased natural period leading to resonance, and increased ductility demands. Past earthquakes demonstrated the importance of considering soil-structure response. Modeling methods include direct and substructure approaches. Eurocode 8 recognizes cases where soil-structure interaction must be considered.
Seismic Design of Buried Structures in PH and NZLawrence Galvez
This document discusses seismic design of buried rectangular structures according to Philippines and New Zealand design codes. It notes that buried structures generally perform better in earthquakes than above-ground structures due to less dynamic amplification effects. While the Mononobe-Okabe method is commonly used internationally for seismic design, the document argues this method has limitations and conservatisms. It reviews Philippines and New Zealand code requirements, which generally do not consider dynamic earth pressures for buried structures. The document proposes simplified seismic design approaches are needed to minimize conservatism for buried structures.
INFLUENCE OF SOIL-STRUCTURE INTERACTION ON RESPONSE OF A MULTI-STORIED BUILDI...SJ BASHA
This document discusses analyzing the influence of soil-structure interaction on the response of a multi-storied building to earthquake forces. It focuses on a 12-story building located in Amaravathi, India, which consists of different soil/rock profiles. Earthquake analysis is performed with the building resting on different soil types, and the fundamental time periods, base shears, and displacements are compared to a fixed base condition. The equivalent lateral force method and free vibration analysis are used to evaluate the structural response considering soil-structure interaction effects. Results are presented and conclusions are drawn regarding how soil properties influence seismic behavior.
Temporary Tie Backs in the Building Construction by Bill Morales MSc CCEBill Morales MSc
Temporary tieback walls were used to support deep excavations for a construction project with buildings surrounding the site. The project involved excavating an 18m by 4.5m pit in stages, with tied-back shotcrete walls on the south, west and east sides and a traditional wall on the north side. A total of 246 tiebacks were installed over 4 stages as excavation proceeded downwards. The tiebacks were designed for temporary support only and were later removed once construction was complete. The anchored walls successfully supported the excavation and adjacent buildings, including during a 6.5 magnitude earthquake during construction.
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.
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.
Transfer Slabs Beams Design Tall Building- تصميم بلا طات وجوائز التحويل الأب...Dr.Youssef Hammida
Transfer Slabs Beams Design Tall Building- تصميم بلا طات وجوائز التحويل الأبنية البرجية- Construction of Transfer Plate
It is the Slab / Beam from which picked up columns may be started where there are no columns underneath. So, it is a kindl of frame in which upper storey columns are directly supported over these slab and hence are cr... more abstract
The document discusses soil-structure interaction (SSI), which refers to how the motion of a structure influences the response of the soil and vice versa. It notes that SSI effects are more prominent for structures where piston-action effects are significant. The types of SSI are inertial, kinematic, and foundation deformation interactions. The degree of SSI influence depends on soil stiffness, structural properties, and dynamic characteristics. Two common analysis methods are the direct method using finite element modeling and the substructure method, which is more computationally efficient. Factors like soil compressibility and regional subsidence can affect SSI, with resonance effects also influencing seismic response due to SSI.
The document discusses the Torino Metro Line 1 project in Italy. It describes the general characteristics of the metro line including the tunnel dimensions, length, and stations. It then discusses several key aspects that had to be managed for the project, including the contract type, procurement of a tunnel boring machine, complex design process due to the urban environment, public opinion, legislative conditions, and environmental requirements. The geology of the tunnel route consisting of quaternary deposits is also summarized.
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.
1. The document examines the use of Tunnel Stability Factor (TSF) to estimate convergence and face stability in weak rock tunnels. TSF considers rock mass strength, overburden height, and tunnel size.
2. Parametric numerical analyses were conducted on 74 tunnels varying in size, depth, and rock mass quality. Dimensionless plots of plastic zone radius and convergence vs TSF showed good correlation despite varying conditions.
3. Guidelines for criticality of stability were developed based on convergence-to-radius ratio ranges associated with TSF levels, indicating severe squeezing for TSF < 0.2 and increased risk of collapse below 0.3 without support.
This document provides information about retaining walls. It defines retaining walls and their purpose to provide stability to natural terrain when slopes are modified. It describes the main types of retaining walls: gravity walls, cantilever walls, and counterfort walls. It also discusses the loads acting on retaining walls, including active earth pressure, passive earth pressure, self-weight, and surcharge loads. The document includes an example problem to calculate the factor of safety against sliding and overturning for a concrete gravity retaining wall.
- Soil-structure interaction (SSI) describes how the response of soil influences the motion of a structure, and vice versa, rather than having independent displacements.
- The three critical aspects of SSI are: 1) Inertia effects on base shear and moment, 2) How base shear relates to foundation/soil displacement, 3) How moment relates to foundation/soil rotation.
- The degree of SSI influence depends on soil stiffness, structure properties like period and damping, and structure stiffness and mass. SSI is more important for flexible structures on soft soil.
Auvinet exc foundations and geotechnical hazards cfpbolivia
The document provides an overview of geotechnical hazards and challenges for excavations and foundations in Mexico City, where the soft lacustrine clays are highly compressible and susceptible to subsidence. Three key points:
1) The subsoil of Mexico City can be divided into three zones (foothills, transition, lake) with the lake zone containing the most compressible clays. Subsidence rates in some areas exceed 1m per year due to groundwater extraction.
2) Excavations require lateral support systems like sheet piles, diaphragm walls, or precast walls due to the low shear strength of the clays. Design must consider failures of slopes, walls, or the excav
SOIL STRUCTURE INTERACTION STUDY ON PLANE BUILDING FRAME SUPPORTED ON PILE GR...IAEME Publication
Background/Objectives: The main objective of this work is to determine the soil interaction of a plane building frame underpinned by pile groups which are embedded in cohesive soil (clayey soil).Methods: The impact of Soil-Structure Interaction on response of a 4 storey framed Building underpinned by Pile group is reported in this paper. The four storey frame consists of three bays and columns of the frame supported by a pile group. The Pile group is presumed to be embedded in the Cohesive soil mass (clayey soil). The soil mass is represented by equivalent springs. The displacement of the building frame caused due to the deflection of the foundation with and without Soil Structure Interaction is analyzed using ANSYS. Findings: Soil non-linearity in lateral direction is indicated by the P-Y curve developed using Matlock equations. The soil properties which are used for clay (cohesive soil) are from the Triaxial Consolidated Undrained Compression Test on soil. Shear Force and Bending Moments at the base of the columns are determined for the frame which is analyzed with and without consideration of soil structure interaction.
Foaming and polymeric agents used in test for the conditioning of soils during the progress of excavation work for a tunnel with a mechanized shield of the TBM EPB type.
The Rion Antirion bridge in Greece connects the Peloponnese peninsula to the mainland across the Gulf of Corinth. Its foundations had to withstand severe environmental conditions including weak soils, earthquakes up to magnitude 7.0, and long-term tectonic movements. The innovative foundation concept adopted reinforced the natural ground with steel tubular piles and included a gravel layer between the piles and foundation raft. This provided capacity to resist the large seismic forces while minimizing differential settlement hazards. Extensive site investigations characterized the poor soil properties to ensure compatible design of seismic demand and foundation capacity.
The document summarizes the design and construction of the foundations for the Rion Antirion Bridge in Greece. Key points:
- The foundations had to withstand severe environmental conditions like weak soil, earthquakes, and tectonic movements. An innovative concept was adopted using large diameter caissons resting on reinforced natural ground with steel pipe inclusions.
- Under each caisson, 150-200 steel pipe inclusions 2m in diameter were driven into the soil in a 7m grid to reinforce it. A 2.8m thick gravel layer separated the caisson from the inclusions.
- This concept provided capacity design by allowing sliding at the gravel interface during large seismic forces, limiting forces on the super
Lyapichev: Analysis, design & behavior of CFRDsYury Lyapichev
Comprehensive numerical analysis, design & behavior of some high concrete face rockfill dams (CFRDs) are given including recommendations for improvement their safety in seismic regions .
The document summarizes the design and construction of the foundations for the Rion Antirion Bridge in Greece. An innovative foundation concept was adopted using steel tubular piles driven into the seabed to reinforce the soil, with a gravel layer between the piles and the concrete caisson foundation. This concept provided seismic capacity and minimized differential settlement risks. Close cooperation between designers, contractors, and reviewers was essential to developing and implementing this challenging foundation solution.
Presentazione torino 5 aprile 2016 vancouver con noteGuido Bentivoglio
1. The document discusses risk management strategies for tunneling projects, using the Vancouver Canada Line tunnel as a case study. It faced risks from unstable soil and proximity to buildings.
2. To mitigate risks to nearby towers, tunnelers lowered the alignment, increased spacing between tunnels, improved soil conditioning, and located maintenance areas in safer locations. These steps allowed tunneling without damaging the towers.
3. Proper risk management through measures like controlling excavation parameters, monitoring ground movements, and adapting tunnel design based on geological conditions helped complete the challenging tunneling project successfully and safely.
This document discusses the design of pillars in underground coal mining. It notes that pillar failure can be either gradual or sudden, with sudden failures causing disasters. Statutory guidelines for pillar dimensions are provided but have limitations as mine depths increase. The author proposes modifications to the standard formula for calculating rock load on pillars to account for dynamic loads during pillar extraction, with a dynamic load factor. Two common formulas for estimating pillar strength are examined, with the author noting limitations and suggesting greater consideration of pillar width in the calculations. Overall, the author aims to provide a more scientifically-based approach to pillar design for stability during formation and extraction.
This document discusses the design of pillars in underground coal mining. It notes that pillar failure can be either gradual or sudden, with sudden failures causing disasters. Statutory guidelines for pillar dimensions are provided but have limitations as mine depths increase. The author proposes modifications to the standard formula for calculating rock load on pillars to account for dynamic loads during pillar extraction, with a dynamic load factor. Two common formulas for estimating pillar strength are examined, with the author noting limitations and making suggestions to better account for depth and pillar width factors. Overall, the author aims to provide a more scientifically-based approach to pillar design for stability during formation and extraction.
The Rion Antirion Bridge project involves constructing a 3 km long multi-cable stayed bridge across the Gulf of Corinth in western Greece. It will be one of the largest bridges of its type in the world. The project faces significant engineering challenges due to high seismic activity in the region, deep weak soil layers, and the potential for fault displacements. Sophisticated dynamic analyses and foundation designs were required to develop a structure that can withstand strong earthquakes while maintaining serviceability. The bridge design utilizes seismic isolation of the deck and innovative reinforced soil foundations to improve bearing capacity and control failure modes under high seismic loads.
Inelastic seismic response of single-story structure in hilly areas owing to ...IRJET Journal
This document summarizes a study that examines the inelastic seismic response of single-story reinforced concrete structures in hilly areas subjected to sloping ground and bidirectional ground motions. Three typical single-story structural models are developed with columns of varying heights due to slope angles of 15, 25, 35, and 45 degrees. The study analyzes the response of these structures both with and without beam-column joints. It also evaluates using a tuned liquid damper and masonry infill walls as mitigation techniques to reduce vibration and deformation from earthquakes. The conclusions of the study could help update seismic design code provisions for structures in hilly terrain.
special concrete and high performance concreteErankajKumar
GROUTING OF CONCRETE, advantage ofGrouting,Characteristics of Grouting, GUNTING OF
CONCRETE, Application of Guniting, Properties of Guniting, advantage and disadvantage of Guniting, UNDERWATER CONCRETING, Properties of underwater concrete, METHODS OF UNDERWATER CONCRETE, advantage and disadvantage of underwater concrete, HOT WEATHERING CONCRETE, precautions, COLD WEATHER CONCRETING, PUMPABLE CONCRETE, Requirements of Mix Design for Pumpable Concrete, Ready Mixed Concrete RMC, Types of Ready Mixed Concrete, advantage and disadvantage of ready mixed concrete, introduction in High performance concrete HPC, selection of materials, behaviour of fresh high performance concrete HPC , behaviour of Hardened High performance concrete HPC when to use High performance concrete HPC , application of HPC , Advantage of HPC , Limitations of HPC
This document is a seminar report on foundations and their types. It discusses shallow foundations like isolated, wall, combined, and strap footings as well as raft foundations. It also discusses deep foundations like pile foundations. Pile foundations transfer loads through skin friction and end bearing. Piles can be friction piles that transfer load through skin friction or end bearing piles that transfer load through end bearing. The report provides details on pile foundation classification and properties that affect foundation selection like soil bearing capacity, properties, and distribution of base pressure. It aims to study different foundation types and their uses based on soil and structural load conditions.
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.
This document discusses the foundation design processes for two major bridge projects - the Vasco da Gama Bridge in Lisbon, Portugal and the Rion-Antirion Bridge in Greece. For the Vasco da Gama Bridge, the foundations consisted of vertical large diameter bored concrete piles due to favorable soil conditions and design requirements. For the Rion-Antirion Bridge, the soil conditions were less favorable so an innovative foundation concept was developed and implemented, which allowed for some permanent displacement under seismic loading. The additional time for design of the Rion-Antirion Bridge was crucial to developing and validating this new foundation solution.
This document discusses geological considerations for successful tunneling. It describes how the rock type, geological structures, and groundwater conditions can impact tunnel construction. Competent rocks like massive igneous rocks allow safe but slow tunneling without lining, while incompetent or fractured rocks require support. Folded or jointed rocks, fault zones, and water-bearing formations present challenges. Proper site investigation is needed to evaluate the geology and plan appropriate excavation and support methods.
The document summarizes the design and construction of the foundations for the Rion Antirion Bridge in Greece. Key points:
1) The foundations used an innovative design of large diameter gravity caissons resting on reinforced natural ground, with steel tubular inclusions and a gravel layer, to address weak soil conditions, seismic activity, and tectonic movements.
2) Subsurface investigations found deep alluvial deposits with low strength and shear wave velocities, posing challenges for the large bridge piers.
3) The foundation concept used capacity design principles, with the gravel layer absorbing inelastic deformations and inclusions providing overstrength to prevent deep failures, allowing sliding if design loads were exceeded.
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 provides an overview of longwall top coal caving (LTCC), which is a method of underground mining used to extract thick coal seams over 4.5m. LTCC uses a longwall setup with powered roof supports and a rear conveyor to allow the top section of coal to cave into the goaf area behind the face. Key factors that influence the success of LTCC include the coal seam characteristics, surrounding rock strata, stress conditions, and fracture development in the top coal. Challenges to implementing LTCC include geological and geotechnical considerations, impacts to the mining environment, and equipment design requirements.
The document discusses literature related to longwall mining geo-technical studies conducted at Ramagundam region in SCCL, India. It summarizes the key findings from 9 completed longwall panels at GDK.10A incline mine including production trends, geological conditions, equipment specifications, and analyses of caving behavior and periodic weighting distances for different panel lengths. Face length was found to influence main and periodic fall spans, with main fall varying between 63-78m for face lengths from 90-170m.
This document discusses underground coal mining methods and operations. It begins by describing different means of accessing underground coal seams, such as adits, shafts, and cross measure drifts. Factors to consider in selecting an access method include coal clearance, ventilation, topography, overburden depth, and costs. It then discusses development work, including driving main roadways and cut-throughs, and the equipment used like continuous miners and roof bolters. Pillars are left behind to support the mine openings, including barrier pillars to separate panels and chain pillars to control subsidence during longwall mining.
This document discusses various foam and resin products used for filling voids, consolidating soils, and waterproofing in tunneling and underground mining applications. It provides details on several products including Silex-330-Foam, PU-8402-Foam, and PU-8408-FR-Foam, describing their properties such as expansion capacity, reaction times, densities, and suitability for use in water-filled environments. The document also mentions a new implosion separation technology for extracting rare earth minerals that is highly sustainable and energy efficient.
I state that I am not looking for candidate but for a "Trust Structure" such as "Trust Company" or "Brokerage Services" or similar that has the skills and knowledge to comunicate with the top management of the Board of two of the most important business credit institutions of the world by capitalization, in the top 10, for the liquidation of some very important "assets", in US currency which, this Foundation, holds the "Power of Attorney".
In my long professional career of almost 45 years, in addition to underground structures, I also had to deal with the structural rehabilitation of bridges, viaducts, embankments, earth and concrete dams.
Therefore, through this new post, I would like to begin to address the problems inherent in the degradation of the concrete of our above-ground infrastructures, using particular resinous and cementitious formulations for the construction, repair and restoration of bridges.
This document discusses polymeric materials for constructing fallout shelters to withstand nuclear radiation. It proposes a new material called Structural Polymer Concrete (SPC) Series 4.0 that has compressive strengths exceeding reinforced concrete, reaching up to 3,000 kg/cm2. SPC 4.0 is proposed as an ideal material for anti-nuclear bunkers due to its high strength and ability to resist effects of nuclear explosions like shock waves, heat, and radiation better than traditional reinforced concrete structures. The document provides details on the formulation and performance characteristics of SPC 4.0 that make it suitable for nuclear fallout shelters.
In 2005, through the pages of a prestigious Italian trade magazine, I turned to readers, if they were aware of how many methods of excavating underground tunnels, with mechanized cutters, could exist in the complex world of mechanical engineering of the subsoil.
Even today, after 17 years, I have received only a few positive feedbacks.
Up to now, the advantage of excavating with circular mechanized cutters arises from the guarantee because we are able to know the structural stability for any type of tunnel. In practice, it has been possible for many years to create tunnels with different cross sections, rather than circular ones.
In fact, it is possible to design, and at the same time excavate, tunnels with rectangular and oval sections, taking into account that, in the underground excavation, there are always stress states that are little known to most of us, even if we are technicians in the sector.
New emerging problems linked to sustainability and innovation are the development of a new concept of underground excavation, developed in the last 30 years, with particular mechanized cutters to create very versatile tunnels, with different types of configurations. The 3 types of excavation machines most used and known today, for the type of soil on which they must operate, are illustrated below, in figure 01) [Silt & Clay, Sand, Gravel and Rock]
As a technician I try to illustrate my geopolitical vision on why there is a lack of raw materials worldwide, recalling that today the technologies used in the mining sector are very advanced compared to yesterday despite the fact that mining companies lack a unified vision and often struggle to use the scarce resources made available on digital investments.
However, despite the mistrust of many mining companies, I would like to point out that it is still possible, especially in this world scenario, to complete any process of technological innovation that is constantly evolving, as is digitization, which is now possible even in 6G mode [where, compared to 5G, speeds of about 206.25 gigabits per second can be reached] as well as artificial intelligence, on which I urge you to pay your attention, because these are the technologies that will help us change many things quickly to get more efficient mines.
In fact, by integrating more access technologies, covering a larger physical space, it is by providing the best basic capacity, such as communication, to be able to go up to the great depths of the subsoil and the sea, with modern equipment that will be increasingly mechanized, in robotic mode, supporting multiple services, not only necessary for excavation, but all this also contributes to greater operator safety and all in "Green" mode.
This is where the policy must be concentrated, towards the company, helping it, with new targeted investments and new regulations, to evolve its organizational characteristics over time and therefore its ability to manage innovation processes, through the modification of new proposals of law to help us coordinate research and innovation on a global level and not for the conquest of new territories, through absurd wars.
The earth's subsoil and the seabed are the resources of all of us and, starting with the creation of a virtual union, worldwide, in which we will all be interconnected and, if we can manage the flow of data in reproducing any object, created to support the reproduction of mixed mining environments between real and virtual, with human-machine interaction in real time, we can really have a significant reduction in costs and very reduced times, in a controlled way, in search of all those minerals that we need, including the "Rare Earths", even without the use of manpower and with the use of fewer and fewer components.
However, my intent is only to begin to do some clarity with you, to make environmental friends better understand and not only that the ways in which environmental issues are addressed today are currently only instrumental, borrowed from some politicians and from politics, because, these gentlemen still have not realized what we are talking about and discussing.
Mr. LAMANNA Luigi Franco Mr. LAMANNA Luigi Franco has worked in these 45 years as a professional consultant and technical management activity in the various civil, industrial, military, hydraulic, railway, motorway sectors and in the last 25 years in the "Tunneling" sector for land consolidation. , their stabilization in excavation, etc.
For the "Mining" sector, in recent years it has been dealing with the extraction of "Rare Earths" and for the stabilization of slopes [open pit mines], consolidation of the rock support, shotcrete, particular
injections with cements or formulations resinous while, in the "Engineering" of particular "Technologies", for the rehabilitation of deteriorated reinforced concrete structures, following earthquakes or other causes, in particular concrete or earth dams.
Particular attention is paid to the use of special and formulated "resinous" cements and related technologies for the consolidation and repair of masonry, iron and wood.
Polymers are commonly used to condition soils excavated by EPB tunnel boring machines (TBMs). Laboratory tests are required to determine the appropriate polymer dosage and conditioning parameters for different soil types. Polyacrylamides (PAs) and partially hydrolyzed polyacrylamide (PHPA) polymers are often used due to their ability to form gels when hydrated and interact with soil particles. PHPA polymers can disperse clays and flocculate clayey soils. Proper conditioning with polymers helps maintain pressure at the excavation face, reduces cutter head friction, and facilitates soil removal.
In 2005, through the pages of a prestigious Italian trade magazine, I turned to readers, if they were aware
of how many methods of excavating underground tunnels, with mechanized cutters, could exist in the
complex world of mechanical engineering of the subsoil.
Even today, after 17 years, I have received only a few positive feedbacks.
The FOUNDATION will create an INNOVATIVE INDUSTRIAL CENTER to support ECO-SUSTAINABLE and ECO-INNOVATIVE projects through research and development of new integrated architecture protocols for air, subsoil and seabed using sixth generation technologies involving participatory startups. The center's objectives are exclusively focused on research and development to innovate humanity and the planet through digital transformation and augmenting the human experience with new materials.
Rock Reinforcement is used to indicated method of enhancing the rock mass strength and hence improving the ability of rock mass to contain the engineering excavation without deforming excessively.
Rock Support is used to indicated method of applying supporting loads or displacement constraints as additional structural elements, so that the engineering excavation retains its integrity.
Commonly an anti-nuclear shelter, equipped with particular technological systems, which ensure the complete aseptic air inside it, is indicated as a housing solution to avoid contamination by nuclear radiation during an armed conflict with the use of unconventional weapons. .
The envelope is usually made from a load-bearing structure in reinforced concrete and built directly underground, in depth, to make the most of the shielding action of the ground to defend itself from contamination by chemical weapons and biological weapons and thus avoid contact with every source of pollution and ensure the survival of the occupants for a very variable period of time.
In the event of a nuclear disaster, the release of radioactive substances [radioisotopes] does not happen all at once, but continues over time in the form of gases, vapors and dust. Hence, our exposure to radioactivity is prolonged and depends on the strength and direction of the winds and on our proximity or distance from the place where the nuclear disaster occurred.
Usually the lining, for this type of excavation, using TBM-EPB, is made with prefabricated concrete segments, and through this memory, I would like to suggest a new technology and related methodology using, instead of the "Pel-Gravel", of the lightweight cellular concrete / concrete CLC [Reported by ACI Committee 523].
What is very important is that even this type of proposed material must also be able to influence the interaction between the support [which is the rock] and the excavation behavior along the tunnel layout.
Let's start this article with the problems of water infiltration through cracks that occur in prefabricated segments after the assembly phase in a new tunnel under construction.
As illustrated several times, in tunnels, especially in metropolitan areas, it very often happens that excavation works must be carried out below the aquifer level, sometimes at quite high pressures. This is a problem that requires a lot of attention on the part of the designer and the executors, since due to the presence of a pitch, the following can occur:
- problems during the excavation phase;
- problems related to alteration of the aquifer;
- problems with infiltration through the joints and / or cracks that occur in the prefabricated segments due to poor execution of the same or for other reasons.
According to Japanese researchers from the Japan Agency for Marine-Earth Science and Technology there are between 80 and 100 billion tons of rare earths at a depth of between 3,500 and 6,000 meters below the botton of the Pacific Ocean in an area that lies beneath the jurisdiction of Hawaii, east of Tahiti in an area under the jurisdiction of French Polynesia and in the Japanese seabed.
At this depth, between 4 and 6 thousand meters, in addition to the presence of rare earths, there are expanses of polymetallic nodules [1], which are chemical sedimentary rocks, siliceous-metalliferous, spherical or lenticular, characterized from a dark crust of black, bluish or brown color, and from an average diameter of 5 cm and which may contain different percentages of minerals depending on the magma from which the degassing originates (they continuously form where clack-smokers are present) .
I would like to point out that in the vicinity of these black-smokers, typical of the oceanic ridge areas, the temperature goes from 400° C up to 1,000° C and the acidity of the sea water is so low that it touches a pH of 2, 8.
Según investigadores japoneses de la Agencia Japonesa de Ciencia y Tecnología Marina-Terrestre, hay entre 80 y 100 mil millones de toneladas de tierras raras a una profundidad de entre 3,500 y 6,000 metros por debajo del fondo del Océano Pacífico en un área que se encuentra debajo de la jurisdicción. de Hawai, al este de Tahití en un área bajo la jurisdicción de la Polinesia Francesa y en el fondo marino japonés.
A esta profundidad, entre 4 y 6 mil metros, además de la presencia de tierras raras, existen extensiones de nódulos polimetálicos [1], que son rocas sedimentarias químicas, silíceo-metalíferas, esféricas o lenticulares, caracterizadas por una corteza oscura de De color negro, azulado o marrón, y de un diámetro medio de 5 cm y que pueden contener diferentes porcentajes de minerales en función del magma del que se origina la desgasificación (se forman de forma continua donde hay clac-fumadores).
Me gustaría señalar que en las cercanías de estos fumadores negros, típicos de las zonas de cordilleras oceánicas, la temperatura va desde los 400 ° C hasta los 1.000 ° C y la acidez del agua de mar es tan baja que toca un pH de 2, 8.
The immediate future of humanity, in my opinion, must not be projected towards the conquest of space but must be directed towards the subsoil of the earth. From now until 2050, the demand for minerals will increase by more than 300% and extraction will grow at unprecedented rates.
Worldwide there is already a real "hunting" for new materials, in particular those called "rare earths", because they can replace, as already happens in certain industrial and strategic sectors [1] those that are normally used as a source of energy together with other minerals [2], always present in the subsoil, but less valuable.
Before moving on to the repair techniques and materials to be used for the reinforcement of the "cortical layer" of concrete, inside a railway tunnel, it is necessary to make a premise premising that, although many repair techniques are known, they are very different from each other when you are in the presence of a road tunnel, made of traditional or fiber-reinforced concrete, and a hydraulic or railway tunnel, made of prefabricated self-supporting ashlars or traditional reinforced concrete, where, overall, in particular, the concept of durability is enormously different.
PUBLICATION IN ITALIAN AND ENGLISH
In the construction and design of a tunnel, the preliminary study of the rock mass along its route cannot be ignored because it is necessary, first of all, even in the first phase of the design, to consider the various aspects: functional, environmental, social, economic, etc. .
However, the fundamental part is given by the behavior of the geological formations, also in relation to water, which must be studied and analyzed both from a geological and geotechnical point of view. These are the most important factors to consider both in the design and construction phase of a tunnel. In particular:
- crossing of faults and milonitized areas with the presence of fluid-plastic soil;
- strong floods of water;
- gas inflows.
NAME:
-Luigi Franco LAMANNA,
SOCIAL POSITION:
-Independent Consultant Tunneling , mining and Oil specialized in mechanized tunneling with Hard Rock TBM and Soft Soil EPB Shields, -Expert and consultant in structural reinforcement (wood, masonry and concrete),
-Chief Executive Officer the FONDAZIONE INTERNAZIONALE DI CENTRO STUDI E RICERCHE - NGO,
ADDRESS:
- Via dei Serpenti 132, 00184 Rome, Italy,
-Phone: +39 06 4742581,
-e-mail: lamannaluigifranco1@gmail.com
More from FONDAZIONE INT.LE CENTRO STUDI E RICERCHE-ONLUS (NGO) (20)
This study Examines the Effectiveness of Talent Procurement through the Imple...DharmaBanothu
In the world with high technology and fast
forward mindset recruiters are walking/showing interest
towards E-Recruitment. Present most of the HRs of
many companies are choosing E-Recruitment as the best
choice for recruitment. E-Recruitment is being done
through many online platforms like Linkedin, Naukri,
Instagram , Facebook etc. Now with high technology E-
Recruitment has gone through next level by using
Artificial Intelligence too.
Key Words : Talent Management, Talent Acquisition , E-
Recruitment , Artificial Intelligence Introduction
Effectiveness of Talent Acquisition through E-
Recruitment in this topic we will discuss about 4important
and interlinked topics which are
Digital Twins Computer Networking Paper Presentation.pptxaryanpankaj78
A Digital Twin in computer networking is a virtual representation of a physical network, used to simulate, analyze, and optimize network performance and reliability. It leverages real-time data to enhance network management, predict issues, and improve decision-making processes.
Accident detection system project report.pdfKamal Acharya
The Rapid growth of technology and infrastructure has made our lives easier. The
advent of technology has also increased the traffic hazards and the road accidents take place
frequently which causes huge loss of life and property because of the poor emergency facilities.
Many lives could have been saved if emergency service could get accident information and
reach in time. Our project will provide an optimum solution to this draw back. A piezo electric
sensor can be used as a crash or rollover detector of the vehicle during and after a crash. With
signals from a piezo electric sensor, a severe accident can be recognized. According to this
project when a vehicle meets with an accident immediately piezo electric sensor will detect the
signal or if a car rolls over. Then with the help of GSM module and GPS module, the location
will be sent to the emergency contact. Then after conforming the location necessary action will
be taken. If the person meets with a small accident or if there is no serious threat to anyone’s
life, then the alert message can be terminated by the driver by a switch provided in order to
avoid wasting the valuable time of the medical rescue team.
Build the Next Generation of Apps with the Einstein 1 Platform.
Rejoignez Philippe Ozil pour une session de workshops qui vous guidera à travers les détails de la plateforme Einstein 1, l'importance des données pour la création d'applications d'intelligence artificielle et les différents outils et technologies que Salesforce propose pour vous apporter tous les bénéfices de l'IA.
Prediction of Electrical Energy Efficiency Using Information on Consumer's Ac...PriyankaKilaniya
Energy efficiency has been important since the latter part of the last century. The main object of this survey is to determine the energy efficiency knowledge among consumers. Two separate districts in Bangladesh are selected to conduct the survey on households and showrooms about the energy and seller also. The survey uses the data to find some regression equations from which it is easy to predict energy efficiency knowledge. The data is analyzed and calculated based on five important criteria. The initial target was to find some factors that help predict a person's energy efficiency knowledge. From the survey, it is found that the energy efficiency awareness among the people of our country is very low. Relationships between household energy use behaviors are estimated using a unique dataset of about 40 households and 20 showrooms in Bangladesh's Chapainawabganj and Bagerhat districts. Knowledge of energy consumption and energy efficiency technology options is found to be associated with household use of energy conservation practices. Household characteristics also influence household energy use behavior. Younger household cohorts are more likely to adopt energy-efficient technologies and energy conservation practices and place primary importance on energy saving for environmental reasons. Education also influences attitudes toward energy conservation in Bangladesh. Low-education households indicate they primarily save electricity for the environment while high-education households indicate they are motivated by environmental concerns.
Generative AI Use cases applications solutions and implementation.pdfmahaffeycheryld
Generative AI solutions encompass a range of capabilities from content creation to complex problem-solving across industries. Implementing generative AI involves identifying specific business needs, developing tailored AI models using techniques like GANs and VAEs, and integrating these models into existing workflows. Data quality and continuous model refinement are crucial for effective implementation. Businesses must also consider ethical implications and ensure transparency in AI decision-making. Generative AI's implementation aims to enhance efficiency, creativity, and innovation by leveraging autonomous generation and sophisticated learning algorithms to meet diverse business challenges.
https://www.leewayhertz.com/generative-ai-use-cases-and-applications/
Generative AI Use cases applications solutions and implementation.pdf
2022_03_ENG_Subsidence.pdf
1. Title:
Brief advice on some corrective measures to be used before and after crossing the ground or rock due to
induced breakdown during the excavation phase of a tunnel in an urban area using the traditional NATM
System or using a TBM-EPB
by Luigi Franco, LAMANNA (*)
1. Introduction
Below I would like to illustrate, through a simple schematic representation, the procedure to be adopted to cross an
area in which there is a "fault", and at the same time try to reduce the consequent damage, following a possible
"collapse" of the soil / rock, during the excavation phase of a tunnel for the metropolitan and / or railway network,
using a TBM-EPB Mechanized Cutter.
The methodological techniques that are usually adopted are very varied, however our only goal, through this
memory, is only to suggest, based on our experience, the types of consumables to be used in such situations, for
engineering applied in underground and highly urbanized environments, and therefore requires a preventive study,
which must be increasingly technologically advanced, to determine the real impact of the construction of these
underground lines on the buildings present on the surface.
Photo 01 – Some examples of subsidence in the metropolitan area
2. Brief and concise illustration of the "subsidence" in situ
We are all aware that if a "collapse" of the ground should occur,during the excavation phase, the TBM will be blocked
because a large "quantity of earth and / or a mass of rock" has entered the cracks, through the cutting disc [cutter],
present on the rotating head of the mechanized cutter
So, first of all, the TBM operator will try to try to "delete any errors", in particular, by performing some actions to be
able to unlock, pulling the TBM back. Therefore, as a first activity, he will try to:
- remove the block "of the earth or rock mass";
- stabilize the "ground / rock" in front of the rotating head, called in the jargon "excavation face";
- it is then to evaluate whether it is necessary to create a "unlocking pilot tunnel", this is necessary to get in front of
the "rotating cutting head" [of the mechanized cutter], which is the external part on which the tools are placed
[cutters], whose function is to break up the soil, to remove the latter [the earth] or the collapsed rock mass,
performing reinforcement treatments, by means of rapid injections of particular "chemical resins" and verify the
causes of the "collapse and / or the phenomenon of subsidence" that has arisen, assess any damage [even the TBM
cutter itself can suffer considerable damage] and make very important decisions on how to intervene.
All
photos
illustred
are
copied
from
the
WEB
2. Once all this has been done, which requires very long treatment times to eliminate the elastic component of the
deformation, the TBM can be started again and immediately afterwards, the excavation can be continued.
Thus described it seems very simple, but in reality we are faced with a truly complex geological event because, during
the excavation phase with a TBM-EPB, and in a highly urbanized area, it is necessary to have preventive control, to
respect fundamental constraints. In particular:
1. avoid damage to the infrastructures and buildings on the surface present in the urbanized area;
2. guarantee the safety of workers in all phases of work because the staff has to work in small spaces and many
times, to unlock the TBM head, small charges must be detonated, creating the problem of manually removing the
rock fragments;
3. check the normal increase in stresses in the temporary lining as a result of the decay of the soil resistance
parameters, asymmetrical loads (due to geomorphology, in particular in the vicinity of another cavity), and soil
heterogeneity;
4. avoid the triggering and re-mobilization of instability phenomena of the excavation side;
5. recover the most difficult part which is the plastic component through the injection of a stabilizing resin
formulation.
Photo 02 – Example of the subsidence phenomenon outside the metropolitan area
I would like to point out that the construction of metropolitan tunnels in urban environments inevitably produces
an alteration of the stress-strain state of the ground. The effect is felt at the level of the country / road level in a
more sensitive way the more superficial the tunnels themselves are: the mechanized excavation and the ways in
which this is carried out inevitably produce the development of subsidence that also spread over great distances
and can sometimes have a catastrophic impact on the urban environment due to the presence of artefacts and
infrastructures close to the excavations [v. buildings, bridges, roads, railway lines, etc.] and this particularly
conditions the choice of the excavation technique, especially the one in which mechanized TBM-EPB cutters are
used, or those with the traditional system [NATM Method] or even open pit [Cut and Cover], where all must prevent
and minimize any subsidence phenomena that may occur on the surface.
I remind the technicians of the sector that many times the phenomenon of "subsidence", during the excavation
phase, in particular using TBM-EPB, is caused by consolidation processes of clayey sediments due to a decrease
in water content or due to external loads , given their particularity of presenting a high compressibility.
However, the factors that most influence the movements induced by the excavation are due to the tension variations
associated with the various construction phases, in the realization of deep excavations, which involve variations in
the stress state, in the hydraulic boundary conditions and, above all, in the thrust conditions of the surrounding land
that can give rise to appreciable displacements on the surface.
All
photos
illustred
are
copied
from
the
WEB
3. Fig. 01 – Graphic representation of the subsidence basin in correspondence of a superficial tunnel. There subsidence curve varies according
to the type of terrain encountered (coarse-grained soils K = 0.2-0.3 while fine-grained soils the value will be K = 0.6-0.7)
A significant proportion of the displacements produced by the construction of an excavation with the traditional
[NATM Method] or open pit [Cut and Cover] system occurs already before the excavation in the phase of
construction of the support works which, as for the subsequent construction phases, can be understood through the
determination of the so-called "stress path". In fact, by ideally subjecting an element of soil to such stress paths, it
is easy to demonstrate that subsequent inversions of the "stress paths" can be associated with important variations
in the stiffness characteristics of the soils and consequently greater deformations induced in the surrounding volume.
Therefore, the geotechnical and environmental problems connected to the construction of metropolitan or railway
infrastructures, as well as the alteration of the stress equilibrium induced by the excavation, can induce subsidence
of the ground strictly connected with a potential damage to the interference of the buildings [Building Condition
Survey BCS and Building Risk Assessment BRA] and the civil structures existing on the surface, as they are all linked
to the effects that the construction of deep excavations, and therefore involves, as on the physical environment that
surrounds them, an interference with the underground services etc., but will be subject to an in-depth future
memory. However, it should be noted that the construction of underground works, in particular tunnels or
underground and railway stations, is always subject to certain constraints that greatly depend on the conditions of
the place and the type of work to be built.
It is in fact very important to remember that the construction of tunnels for metropolitan and railway transport
requires, in addition to stabilizing the excavation, also the difficult control of the deformation during the entire life
of the work, a requirement which can be met by means of a considerable limitation of the maximum pressures that
are determined on the lining and on the concrete prefabricated segments, definitive in the long term, resulting in
the limitation of the formation and / or failure of the lining. I would like to underline how well the designers of
modern infrastructures are aware that the behavior, particularly that of the rock, whether pushing or swelling, is not
uniform along the tunnel and that therefore the development of pressures in the long term can be extremely
variable.
I would like to point out that, when using the excavation technique using the traditional NATM Method system, a
shotcrete coating, used without particular measures, is not suitable when one is in the presence of pushing or
swelling soils and / or rocks. In these cases our main objective will be to limit the deformation of the ground and /
or the rock by means of a temporary support, but it is often not sufficient to contain the deformation of the rock
and is damaged or completely destroyed by subsidence.
Longitudinal subsidence profile
Excavation face
Extensione of the susubsidence
Transverse subsidence profile
All
photos
illustred
are
copied
from
the
WEB
4. Fig. 02 – NATM Method – Possible ground movements induced by the construction of underground structures. The
color photo illustrates control parameters of foundation buildings [Risk classification according to Rankin, 1988]
However, without using the appropriate precautions, the ground and / or the rock slowly "pushes" the already
broken lining until a position of equilibrium is reached or the excavation collapses. Therefore, one of the appropriate
countermeasures is to introduce yielding ribs together with anchors [a topic already addressed in a previous
memoir].
2.1 - Anchoring to the rock
I would like to briefly illustrate the excavation of tunnels, with the traditional NATM method, which takes place
according to the following phases, because I would like to underline once again what I describe at the bottom of the
conclusion of this point 2.1):
- excavation, carried out with hydraulic hammers operated by compressed air or gas, depending on the expected
behavior of the soil;
- removal of debris;
- safety by laying a pre-coating with metal supporting structural elements (ribs) and subsequent application of
reinforced Spritz-Beton (coating).
In particular, the anchoring to the rock takes place through a structural element operating in traction, capable of
transmitting forces to the ground.
Functional parts of the anchor are:
- the locking device and the distribution plate placed at the head of the bar;
- the reinforcement consisting of steel or glass fiber bars or profiles;
- mechanical expansion anchoring device, or as we want to underline later, by means of a particular formulation of
silicate resin (organo-mineral and non-polluting), in the terminal section of the structural element in order to
guarantee a perfect union between rock and bar .
DIRECTION OF EXCAVATION
All
photos
illustred
are
copied
from
the
WEB
5. Photo 03 – From our experience of tests done in the laboratory using a climatic chamber we have
I was able to verify that the steel bar did not suffer any corrosion and that the particular resin formulated
silicatica has not undergone any degradation but is able to pass aging tests of more than 100 years (500 years)
In the recent past, not to mention even today, the fixing of the steel iron bar was done by injecting a cement mortar.
I would like to underline that the resistance of the anchor depends on the resistance of the reinforcement, on the
adhesion (which can be guaranteed over time only by the injection of the particular formulation of silicate resin)
between rock and bar as well as on the nature of the ground.
The silicate resin formulation that I suggest is a non-polluting product, does not catch fire, is not corrosive,
penetrates cracks of the order of 0.005 inches and also blocks any water present in the subsoil.
3. Some hypotheses to solve the problems that are encountered
The campaign of preventive geognostic investigations being studied aims to characterize the stratigraphy from a
geological, geotechnical and environmental point of view by means of in situ tests along the route of the future
underground or railway line.
In recent decades, the new metropolitan lines and in particular the high-speed railway ones provide for the
construction of tunnels, even of large diameter for the railway ones, and which develop in extremely variable rock
masses, using mechanized TBM-type cutters, even in high convergence rock masses. But thanks to the technological
progress in the field of cutting tools [cutters] and in the power / thrust of modern TBMs, it is now very rare that a
rock formation can be considered economically “unmillable”.
In fact, today the TBM has been developed to operate in adverse rocky conditions and in particular in the presence
of high convergence rock masses and subsidence of the excavation face, even with large diameters [12-15 meters].
The ability of the TBM to operate in such adverse excavation conditions is an essential element in the case of large
diameter tunnels and in the presence of complex geological formations.
In fact, when digging in the presence of a water table, in addition to allowing dry machining, this [the TBM] is able
to ensure the stability of the excavation face, through the control of neutral pressures. The apparently most
advantageous stabilization technique results in a "catchment" of the aquifer which, however, entails inevitable
resentments on the regime of the underground water table in the construction phase.
Particularly interesting and innovative are the most modern techniques for limiting induced settlements for the
protection of existing structures on the surface, through soil consolidation, carried out directly in the construction
phase to compensate for induced resentments.
3.1 - Brief summary of the consolidation intervention in a fault area and in the presence of water flows
Another of the most important aspects during the excavation phases by means of a TBM of a blind hole tunnel in a
fault zone with water flows whose presence, many times, has not been identified by the boreholes. In addition to
All
photos
illustred
are
copied
from
the
WEB
6. causing discomfort in the work environment, these cause instability, especially in difficult terrain. It is therefore
necessary to adopt particular measures, such as the immediate stop of the TBM, to make investigative holes to
obtain information on the nature of the material and the extent of the fault zone, then proceed with a waterproofing
and consolidation through injections of sub-holes horizontal radial pattern (nr. 8 ÷ 10 holes, inclined from 3° ÷ 12°),
of one-component hydro-reactive polyurethane resin of the PU-8402-FOAM type (or a modified formulation called
PU-8408-FOAM type) and then look for to stabilize the landslide front with the insertion and injection of a particular
formulation of organo-mineral resin (foam) of the SILEX-330-FOAM type.
The peculiarity of this new PU-8408-FOAM type product is that, during injection, if the resin comes into contact with
water, it increases in volume, if it does not find water, it hardens without foaming and at the same time pushes the
porous material in the innermost layers forming an impermeable and compact layer of variable thickness.
Fig 04 - Schematic representation of excavation near a fault. Interception of the fault. Unstable material: clay, sand, debris, ect.
Furthermore, the presence of several extended faults, and if there is a high tendency of the front to collapse, in
addition to what has been previously described, it is necessary to create a protective umbrella for the consolidation
of the front up to and beyond 3 meters by intervening on the healthy rock, injecting some product. of the SILEX-330-
FOAM type and if necessary another product of the SILEX-304-STONE type [non-expansive] which, thanks to its high
fluidity, the latter resinous formulation is able to penetrate even through cracks of a few hundred microns in width
In fact, the mixture of a resinous nature tends to follow the major cracks, where the pressure losses are less high, to
the detriment of the minor cracks which remain open.
To solve this, I suggest interrupting the injection for at least 5 minutes, waiting for the already injected product to
catalyze and repeat the treatment until the rejection pressure is reached.
Fig. 05 - Schematic representation of the approach phase with radial perforation and injection (no. 8 holes) of resin type PU-8402-FOAM
INTERCEPTED EOLOGICAL ANOMALY
PROBE HOLES
TBM-EPB
TBM-EPB
Injection of resin
type PU-8402-PU
APPROACH PHASE WITH RADIAL PERFORATION
AND INJECTION
7. 3.1.1) - Some considerations on the injection of polyurethane foam of the "PU-8402-FOAM" type to block the
water on the excavation face.
The range of polyurethane formulations allows the structural consolidation of a large part of the soil, but the use of
one or the other product must be evaluated on site based on the geomorphological characteristics found.
As already mentioned, since most of the products are two-component, they must be injected by means of special
pumps with a static mixer in the head. The component feed pipes, which are separated, can be several meters long,
as long as the pump has sufficient pressure.
Furthermore, as previously mentioned, the type of product "PU-8402-FOAM", being a single-component product
that reacts only in the presence of water or moist soil, having a very long pot-life (even for several days, if stored at
dry), there are no limits of use, subject to sufficient pumping pressure, to the length of the injection pipes.
Fig. 06 - Schematic representation of the approach phase to 3-5 m. with radial perforation and injection (no. 12 holes)
of resin type SILEX-330-FOAM
It should be borne in mind that many of the products mentioned above have been studied and formulated precisely
for the control of water inflows in tunnels, mines and underground works in general. I repeat, the product type "PU-
8402-FOAM" is a polyurethane resin formulation designed specifically for the rapid blocking of water during
excavation with TBM-EPB cutters. When the formulation comes into contact with water, a chemical reaction rapidly
takes place which leads to the formation of a consolidating foam with closed cells, characterized by absolute
impermeability and chemical stability.
I specify that during practical applications on site, to allow the advancement of the TBM, even in difficult soils and
with high water flows, the expansion factor is linked to the quantity of catalyst introduced since, the formulation
type "PU-8402 - FOAM ", is a single-component product that reacts only in the presence of water; in the absence of
water, it remains stable, in the form of a gel, even for several years, and consequently the blocking power of water
is determined by the amount of water present and the pressure of the same and the quantity of catalyst introduced
(from 1 ÷ 5%).
The information described in this study experience led me to conclude that the consolidation and waterproofing
injection interventions in an underground environment, especially in the vicinity of water sources intended for
human consumption, require greater attention and knowledge in the choice of products to be injected. In fact, the
problem of water outflows in tunnels and in underground works in general, must not be seen only as a cause of
delay or increase in costs in the construction phase, but as a rehabilitation and prevention action in order to make
our intervention compatible with environmental protection.
4 - Some hypotheses of preventive safety to avoid in situ subsidence
The route of a tunnel considered that develops in an urbanized environment, the tunnel underpass, with reduced
coverage of the underground line as well as the lithological nature of the subsoil, highlighted by means of a detailed
cost-benefit analysis, it is necessary to decide the most suitable excavation method , as an alternative to the
TBM-EPB
Injection of resin
type SILEX-330-FOAM
APPROACH PHASE WITH RADIAL PERFORATION
AND INJECTION – 3-5 m
8. traditional type, and therefore it is necessary to operate with preventive interventions to contain the excavation in
order to limit subsidence on the surface.
Fig. 07 – Scheme of the stabilization and / or consolidation phase of the ground (bearing capacity), even in the presence of pressurized
groundwater, before excavation with TBM along the path of the future tunnel by injection of resin from above. This type of intervention
must be carried out under the control of the environmental impact. This type of treatment can be carried out when it is possible to
intervene from above, as the tunnel is not very deep, within the metropolitan areas.
A method of treating the stability of the ground of the excavation face is that by means of injections of cement
mixtures and / or resinous formulations which arises from the need to improve the characteristics of mechanical
resistance and impermeability of porous soils or rock masses. The improvement can be obtained with various
injection techniques which can be classified according to the level of inlet pressure and according to the type of
mixtures used. In the construction of metropolitan and / or metropolitan tunnels in urban areas, in recent decades
there has been a notable development, worldwide, on the use of the mechanized balanced pressure shield [TBM-
EPB Earth Pressure Balance Machine] and on the function of chemistry in the treatment of soils through a series of
mixtures that produce the maintenance and stability of the soil of the excavation face.
The mixes can be used in consolidating and / or waterproofing treatments [preventive and otherwise] to allow the
excavation phase in conditions of maximum safety as well as reducing surface subsidence and soil permeability.
5- Conclusions
The design and construction of a tunnel, as we have mentioned above in this brief memoir, is conditioned by multiple
factors that can vary over time according to the evolution of the preliminary knowledge to the final stages, thus
allowing, many times, to adapt the project to the geological-technical conditions that gradually meet.
The convenience of carrying out consolidation interventions, to be defined according to the geological characteristics
and also by the excavation methods, are the fundamental tool for maintaining the integrity of the core at the face
and allowing the advancement of the cutter in an environment that has not already collapsed.
Much has already been illustrated in various articles on the traditional NATM system. There is a wide range of
publications both of a general nature and on specific experiences. While the purpose of this new article of mine is
to draw attention to how some particular types of resinous formulations are participating in the rapid evolution in
progress of the new ways of building new infrastructural tunnels and not with the use of TBMs.
Current TBMs are proving to be able to overcome the exceptional events that may be encountered during excavation
very well, in particular during the excavation of a deep and very high-coverage tunnel, where the forces of nature
can generate unpredictable and extremely critical conditions and that, at the same time, these conditions can be
faced and overcome by innovative methodologies and technologies, as demonstrated daily by the competence and
dedication of many technicians in the sector.
TBM-EPB
9. The introduction of cement injections as a useful means for filling any voids on the back of a coating or for
consolidating the soil or rock surrounding a cavity is now superseded by the use of new silicate-based resinous
formulas (CFC-free and halogens) because these harden in a few minutes and also because the same resins can
participate in supporting part of the load in a short time and be able to combine with the particular geological
conditions that arise.
Fig. 08 – Examples of consolidation underthe roads and manufactured before digging a tunnel for underground
Furthermore, the choice between the different excavation systems is substantially dictated by the geotechnical and
geomechanical characteristics of the soil and the cost / benefit ratio of the intervention. Remembering that
construction times and costs cannot yet be predicted. But finally today the construction of the tunnels has finally
been industrialized for any terrain and tension conditions because the excavation progress no longer depends on
the ground but the terrain is modified in order to proceed as quickly as possible.
In fact, the discussion of these topics, as I have always pointed out in my articles, can often seem trivial. Also to
clarify that preliminary investigations are necessary, both in the design and construction phases, and that the
application of injection procedures, the types and characteristics of the mixtures, as well as their methods, have
become essential in the construction of a tunnel. However, my only purpose is to have, on the basis of the mutual
knowledge and experience of the readers, through the effort to use a simple and respectful language made up of
information exchange, which in this context has nothing to do with deep emotions or with vested interests, but to
arrive all together, through observations, theories, through our cognitive abilities, also made by the different
professional roles, of those who deal with this particular sector, without decentralizing ourselves from our reference
information, we will not be able to understand some of our colleagues and therefore everything would be nothing
more than a simple flawed information. But is not so. Because we need the insights needed for greater
understanding, as well as pre-containment measures. However, the conflicting opinions that can emerge from all
gallery experts, as has happened in the past, are being examined by the undersigned author.
(*) Luigi Franco, LAMANNA
Independent Technical Consultant in the sector of Tunnelling, Mining and Underground Technology
President of the Fondazione Internazionale di Centro Studi e Ricerche, ONG
132, via dei Serpenti, 00184 ROMA, Italy, U.E.
Email: lamannaluigifranco1@gmail.com