This document discusses blasting rock through the use of explosives. It provides an overview of blast design and the types of explosives commonly used, including dynamite, slurries, and ANFO. It explains concepts like burden, stemming, and delay devices. The goal of the document is to provide guidance on designing blast hole layouts and calculating explosive amounts for effective blasting of rock.
numerical study and analytical solution of P-wave attenuation insensitive und...Hamed Zarei
1) The document analyzes P-wave attenuation in underground rock structures through both analytical and numerical methods.
2) Analytical and numerical results show that any vacuum or cavity in rock mass greatly increases P-wave attenuation, while rock material with mechanical strength properties in a virtual space decreases attenuation and increases wave energy transmission.
3) Key parameters analyzed include the density and properties of virtual spaces and joints, and results show that factors like cavity thickness and density contrast have significant effects on wave attenuation.
Intelligent back analysis using data from the instrument (poster)Hamed Zarei
This document presents a model using artificial neural networks for back analysis of tunnel monitoring data from the Chehel Chai water conveyance tunnel in Iran. Input data from 27 parameters across 3 categories were used to train a neural network model on results from 18 convergence stations. The trained model was then able to accurately estimate rock mass elasticity and in situ stress values based on new monitoring data, demonstrating its effectiveness for intelligent back analysis of future tunnel monitoring results.
This document discusses blasting rock through the use of explosives. It provides an overview of blast design and the types of explosives commonly used, including dynamite, slurries, and ANFO. It explains concepts like burden, stemming, and delay devices. The goal of the document is to provide guidance on designing blast hole layouts and calculating explosive amounts for effective blasting of rock.
numerical study and analytical solution of P-wave attenuation insensitive und...Hamed Zarei
1) The document analyzes P-wave attenuation in underground rock structures through both analytical and numerical methods.
2) Analytical and numerical results show that any vacuum or cavity in rock mass greatly increases P-wave attenuation, while rock material with mechanical strength properties in a virtual space decreases attenuation and increases wave energy transmission.
3) Key parameters analyzed include the density and properties of virtual spaces and joints, and results show that factors like cavity thickness and density contrast have significant effects on wave attenuation.
Intelligent back analysis using data from the instrument (poster)Hamed Zarei
This document presents a model using artificial neural networks for back analysis of tunnel monitoring data from the Chehel Chai water conveyance tunnel in Iran. Input data from 27 parameters across 3 categories were used to train a neural network model on results from 18 convergence stations. The trained model was then able to accurately estimate rock mass elasticity and in situ stress values based on new monitoring data, demonstrating its effectiveness for intelligent back analysis of future tunnel monitoring results.
The document discusses brittle fracture and stress-controlled failure in tunneling. It describes how stresses concentrate and relax around underground excavations, which can lead to problems like spalling and rockbursts. Spalling occurs when stresses concentrate and exceed the rock strength, causing slabs or wedges to detach from the tunnel walls or roof. Rockbursts are sudden violent failures caused by the buildup and release of strain energy. The document examines failure mechanisms from both phenomenological and mechanistic perspectives, discussing theories like Mohr-Coulomb criteria and Griffith crack propagation theory. It emphasizes that brittle rock strength is stress-dependent and damage initiates at stresses well below peak strength.
The document discusses the New Austrian Tunnelling Method (NATM) for excavating tunnels in weak rock. Some key points of the NATM include: (1) controlling ground deformations by applying early temporary support like rock bolts and shotcrete, (2) using flexible support that deforms with the ground, and (3) closing the tunnel invert quickly to form a load-bearing ring. The NATM also emphasizes monitoring ground movements and revising support as needed to maintain stability. While economical by matching support to conditions, the NATM requires cooperation between engineers to determine daily support requirements.
Tunnelling & underground design (Topic5-hard & weak rock tunnelling)Hamed Zarei
The document discusses different methods for excavating tunnels in rock, including drill-and-blast and mechanical excavation using tunnel boring machines (TBMs). Drill-and-blast involves drilling holes, loading them with explosives, and detonating them in a sequence according to a blast design. TBMs can excavate continuously using a rotating cutter head equipped with cutting tools. Factors that influence the performance of each method include rock properties, drilling/cutting rates, tool wear, and downtime. The goal is to optimize the energy used and fragmentation produced during excavation.
This document discusses various tunnelling methods for soft ground, including cut and cover, shield tunnelling using compressed air or slurry, and earth pressure balance tunnelling. Cut and cover involves excavating a trench and placing pre-cast concrete segments, and was used for 75% of the Canada Line project in Vancouver. Shield tunnelling methods provide constant support to the advancing tunnel face. Compressed air shields fell out of favor due to health and safety issues, while slurry shields use bentonite slurry to support the face but require expensive separation plants. Earth pressure balance tunnelling was developed to address limitations of slurry shields, supporting the face through pressure control without slurry or separation plants.
Tunnelling & underground design (Topic3-geotechnical data baseline reports)Hamed Zarei
This document discusses risk management in tunneling projects. It begins by providing context on managing hazards in tunneling projects such as contractual disputes, unforeseen conditions, and equipment failures. It then discusses how contracts are used to manage financial risk and trends toward design-build contracts with tight schedules and budgets. An example is given of the St. Gotthard tunnel project that went over budget and late due to pressure to meet deadlines. The document outlines the risk management process of identifying hazards, analyzing probability and consequences, evaluating risk, and implementing risk reduction measures. It discusses owner-contractor roles and responsibilities in risk management as well as types of tunneling contracts and approaches to construction delivery such as design-build. The document concludes
The Gotthard Base Tunnel project in Switzerland faced significant geological uncertainties and challenges during construction. Known risks included water inflows and weak ground conditions in brittle fault zones, squeezing ground in weak rock masses, and potential rockbursts in deep, high-stress sections. Unknown risks that emerged included unexpectedly thick and extensive buried valleys during the construction of the Lötschberg Base Tunnel, which caused a major flood during construction. For the Gotthard Base Tunnel, running ground conditions in water-saturated dolomite formations and the crossing of subhorizontal faults near Faido presented challenges that led to project delays and cost overruns. Addressing these complex geological conditions and unknowns required extensive geological investigations and flexible tunnel construction
Tunnelling & underground design (Topic1-introduction to the tunnelling industry)Hamed Zarei
This document provides an overview of past and present tunnelling projects and challenges. It discusses the stuck Bertha tunnel boring machine in Seattle which has been stuck since 2013 due to overheating. It also discusses cost overruns and litigation on the Seymour-Capilano Twin Tunnels project in BC. Finally, it provides details on the course topics, lectures, and assignments for an introduction to tunnelling class.
Modeling of twain Tunnel water conveyanceHamed Zarei
1. The document discusses creating a tunnel model using PLAXIS software, including defining the geometry, material properties, and boundary conditions of the tunnel and surrounding rock.
2. A horseshoe-shaped tunnel with a diameter of 5.3m and space of 12m between tunnels is modeled. Rock and shotcrete material properties are input along with standard earthquake boundary conditions.
3. Dynamic analysis is performed by applying a prescribed displacement at the bottom boundary and vertical harmonic load to model an earthquake, with results viewed in output graphs.
NATM (New Austrian Tunneling Method ) in TunnelingHamed Zarei
1. NATM (New Austrian Tunneling Method) is a flexible tunneling method that utilizes shotcrete, wire mesh, rock bolts, and lattice girders for tunnel support. It mobilizes the strength of the rock mass and uses dynamic design that adapts the support based on rock conditions.
2. Excavation in NATM progresses from top heading to benches in poor rock. It is done in small sequential cells to support unstable ground. Primary lining of shotcrete is applied immediately after excavation.
3. Rock mass is classified using methods like RQD, RMR, and Q-factor to determine appropriate support. Flexible shotcrete and bolting allow adaptation to changing geology encountered during tunnel
The document discusses brittle fracture and stress-controlled failure in tunneling. It describes how stresses concentrate and relax around underground excavations, which can lead to problems like spalling and rockbursts. Spalling occurs when stresses concentrate and exceed the rock strength, causing slabs or wedges to detach from the tunnel walls or roof. Rockbursts are sudden violent failures caused by the buildup and release of strain energy. The document examines failure mechanisms from both phenomenological and mechanistic perspectives, discussing theories like Mohr-Coulomb criteria and Griffith crack propagation theory. It emphasizes that brittle rock strength is stress-dependent and damage initiates at stresses well below peak strength.
The document discusses the New Austrian Tunnelling Method (NATM) for excavating tunnels in weak rock. Some key points of the NATM include: (1) controlling ground deformations by applying early temporary support like rock bolts and shotcrete, (2) using flexible support that deforms with the ground, and (3) closing the tunnel invert quickly to form a load-bearing ring. The NATM also emphasizes monitoring ground movements and revising support as needed to maintain stability. While economical by matching support to conditions, the NATM requires cooperation between engineers to determine daily support requirements.
Tunnelling & underground design (Topic5-hard & weak rock tunnelling)Hamed Zarei
The document discusses different methods for excavating tunnels in rock, including drill-and-blast and mechanical excavation using tunnel boring machines (TBMs). Drill-and-blast involves drilling holes, loading them with explosives, and detonating them in a sequence according to a blast design. TBMs can excavate continuously using a rotating cutter head equipped with cutting tools. Factors that influence the performance of each method include rock properties, drilling/cutting rates, tool wear, and downtime. The goal is to optimize the energy used and fragmentation produced during excavation.
This document discusses various tunnelling methods for soft ground, including cut and cover, shield tunnelling using compressed air or slurry, and earth pressure balance tunnelling. Cut and cover involves excavating a trench and placing pre-cast concrete segments, and was used for 75% of the Canada Line project in Vancouver. Shield tunnelling methods provide constant support to the advancing tunnel face. Compressed air shields fell out of favor due to health and safety issues, while slurry shields use bentonite slurry to support the face but require expensive separation plants. Earth pressure balance tunnelling was developed to address limitations of slurry shields, supporting the face through pressure control without slurry or separation plants.
Tunnelling & underground design (Topic3-geotechnical data baseline reports)Hamed Zarei
This document discusses risk management in tunneling projects. It begins by providing context on managing hazards in tunneling projects such as contractual disputes, unforeseen conditions, and equipment failures. It then discusses how contracts are used to manage financial risk and trends toward design-build contracts with tight schedules and budgets. An example is given of the St. Gotthard tunnel project that went over budget and late due to pressure to meet deadlines. The document outlines the risk management process of identifying hazards, analyzing probability and consequences, evaluating risk, and implementing risk reduction measures. It discusses owner-contractor roles and responsibilities in risk management as well as types of tunneling contracts and approaches to construction delivery such as design-build. The document concludes
The Gotthard Base Tunnel project in Switzerland faced significant geological uncertainties and challenges during construction. Known risks included water inflows and weak ground conditions in brittle fault zones, squeezing ground in weak rock masses, and potential rockbursts in deep, high-stress sections. Unknown risks that emerged included unexpectedly thick and extensive buried valleys during the construction of the Lötschberg Base Tunnel, which caused a major flood during construction. For the Gotthard Base Tunnel, running ground conditions in water-saturated dolomite formations and the crossing of subhorizontal faults near Faido presented challenges that led to project delays and cost overruns. Addressing these complex geological conditions and unknowns required extensive geological investigations and flexible tunnel construction
Tunnelling & underground design (Topic1-introduction to the tunnelling industry)Hamed Zarei
This document provides an overview of past and present tunnelling projects and challenges. It discusses the stuck Bertha tunnel boring machine in Seattle which has been stuck since 2013 due to overheating. It also discusses cost overruns and litigation on the Seymour-Capilano Twin Tunnels project in BC. Finally, it provides details on the course topics, lectures, and assignments for an introduction to tunnelling class.
Modeling of twain Tunnel water conveyanceHamed Zarei
1. The document discusses creating a tunnel model using PLAXIS software, including defining the geometry, material properties, and boundary conditions of the tunnel and surrounding rock.
2. A horseshoe-shaped tunnel with a diameter of 5.3m and space of 12m between tunnels is modeled. Rock and shotcrete material properties are input along with standard earthquake boundary conditions.
3. Dynamic analysis is performed by applying a prescribed displacement at the bottom boundary and vertical harmonic load to model an earthquake, with results viewed in output graphs.
NATM (New Austrian Tunneling Method ) in TunnelingHamed Zarei
1. NATM (New Austrian Tunneling Method) is a flexible tunneling method that utilizes shotcrete, wire mesh, rock bolts, and lattice girders for tunnel support. It mobilizes the strength of the rock mass and uses dynamic design that adapts the support based on rock conditions.
2. Excavation in NATM progresses from top heading to benches in poor rock. It is done in small sequential cells to support unstable ground. Primary lining of shotcrete is applied immediately after excavation.
3. Rock mass is classified using methods like RQD, RMR, and Q-factor to determine appropriate support. Flexible shotcrete and bolting allow adaptation to changing geology encountered during tunnel