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The effect of a nonlinear Mohr-Coulomb criterion on the stresses and plastic deformation near a circular opening in poorly consolidated permeable medium
EXCAVATIONS:OPENING probability,
reliability and reliability index of single failure
mode are discussed under u-constraint level. The same are then derived using a fuzzy random approach. (from English summary) 967263 A structural reliability algorithm (in Chinese)
analysis
method based on genetic
Zhao Yangang & Jiang Jinren, Earthquake Engineering & Engineering Vibration, 15(3), 1995, pp 45-58. Presents a genetic algorithm for searching the most likely failure point which is not limited by restrictive assumptions about search space, such as continuity or existence of derivatives. The workings of genetic algorithm in structural reliability are investigated and three intellectual faculties are introduced to improve the search process. From examples it is found that the problems in deciding the length of strings can be effectively improved. (from English summary) 967264 Stochastic response analysis of tall building structures with added hysteretic energy dissipation devices (in Chinese) Tian Qianli, A. K. H. Kwan & Y. K. Cheung, Earthquake Engineering & Engineering Vibration, 15(2), 1995, pp 109117.
An approximate method is presented to analyse tall building structures with added hysteretic energy dissipation devices. The structure is modeled as a cantilever beam on hysteretic nonlinear supports. Its governing equation is derived by using Ritz method and linearized in each iterative step, based on an equivalent linearized method. This method is relatively inexpensive in computation and therefore allows assessment of effects of various parameters on responses. Results show that the use of wire-cable isoslator combined with viscoelastic damping layers is a good example of energy dissipation device, so it is recommended as a novel aseismic mechanism. (English summary) 967265 The singular solutions of axisymmetric elastodynamic problem for multilayered halfspace by means of transfer matrix (in Chinese) Meng Fanshun, Guo Haiyan & Yie Tianqi, Earthquake Engineering & Engineering Vibration, 15(2), 1995, pp 44-51. A singular solution of the axisymmetric elastodynamic problem for the multilayered halfspace due to any axisymmetrical dynamic load acting within layered media is derived in the time domain with the aid of Laplace-Hankel mixed transforms and transfer matrix method. This method is clear and the corresponding formulas simple and convenient. An example is presented. (from English summary) 967266 An introduction to the method and analytical program for prediction of earthquake damage of rectangular reinforced concrete cistern (in Chinese) Guo Endong & Feng Qimin, Earthquake Engineering & Engineering Vibration, 15(2), 1995, pp l-9.
A method and an analytical program for prediction of earthquake damage to rectangular reinforced cisterns are presented. The results of earthquake damage prediction of two cisterns are obtained using this method and program. The conclusion is that the underground cistern has better earthquake resistance compared with ground cisterns. (from English summary) 967267 Analytical solutions of viscoelastic multilayered halfplane problem to an arbitrary buried source (in Chinese) Meng Fanshun, Yang Dehai &Wang Youlong, Earthquake Engineering & Engineering Vibration, 15(3), 1995, pp 32-37.
Assuming the 2-dimensional plan strain state, analytical solutions of viscoelastic multilayered halfplane problem to an arbitrary buried source are derived with the aid of Fourier-
STRESS
323A
transforms and transfer matrix me presented. (from English summary)
EXCAVATIONS Genera 967268 The use of underground space in Hong A. W. Malone, Tunneiling & Undergroun 1 l(l), 1996, pp 57-64.
e Techno1ogy,
In 1991, the Hong Kong Government adopted a policy of encouraging development in rock caverns, where such development is appropriate. The underground aption has recently been selected for certain facilities considered environmentally unattractive for surface placement. The aper discusses technical aspects of some of the cavern schemes currently under construction. It also traces the history of cavern usage in Hong Kong and describes the Hong Kong Geotechnical Engineering Office’s study of the potential use of underground space in Hong Kong. (Author)
Geological
factors
967269 A soft layer to control soil arching abode a basic
A. N. Dancygier
& D. Z. Yankelevsky,
~~~~~~er~ng
Structures, 18(5), 1996, pp 378-386.
The possibility of controlling arching by application of a soft layer in the soil above a roof is investigated and described. New definitions, that better describe various aspects of the phenomenon, are proposed, and used in a quantitative analysis of the problem. The effects of the soft layer are discussed and it is shown that there is an optimal length of the soft layer that yields minimal loading on the buried roof. (from Authors) 967270 Modelling of ground movements layered ground R. J. Grant & R. N. Taylor, Ground ~~gi~eeri~~, 29(l), 1996, p 29. A project is described in which a 2D or plane strain analogue is being used to study the effect of tunnelling in layered ground using both physical model tests and numerical analysis. The main objective of the work is to improve methods of estimating surface and subsurface movements caused by tunnelling in layered ground. Analysis of the various test data indicates the following: surface and subsurface settlement troughs within both the sand and the clay are reasonably represented by the commonly assumed Gaussian distribution; the settlement trough width is independent of volume loss due to tunnel excavation; the width of the subsurface settlement troughs tends to be greater than predictions made using current practice. (from
Stresses around openi 967271 The effect of a nonlinear Mohr-Couliomb crit stresses and plastic deformation n poorly consolidated permeable m Y. Wang, International Journal of eeb~~~c~& Mining
Sciences, 33(2), 1996, pp 197-203. A closed-form solution for the stresses near a circuiar opening is presented. A nonlinear MC criterion is introduced which is used to govern the permissible stresses near opening. Poroelastic medium is assumed for those regions where stress state is within the criterion envelop and a perfects plastic medium is assumed for the regions in which such a criterion is exceeded. Only a steady state flow is considered which can be decoupled from the deformation. According to the calcula-
324A
EXCAVATIONSTUNNELS
tion the stresses by a linear MC criterion are overestimated, but the plastic radius is underestimated. Both the effective tangential stress and the plastic radius can be significantly affected by pore pressure penetration. It is concluded that the pore pressure penetration effect on the stress analyses and plastic zone prediction must be incorporated. (Author) 967272 The use of stress-strength relationships in the assessment of tunnel stability R. Bhasin & E. Grimstad, Tunnelling & Underground Space Technology, 1l(l), 1996, pp 93-98. A method of predicting probable ground behaviour considering stress-strength relationships is presented. The influence of overburden pressure and rock mass strength are considered in forecasting stability problems in tunnels. In particular, squeezing, spalling and loosening of the rock mass in tunnels constructed through the complex geological set-up of the Himalayas have been analysed. A new Q-system correlation which takes into account the dimension of an opening is suggested for evaluating support pressures in squeezing ground. (from Authors)
Excavation
failure mechanisms
of itself would prevent the construction of road tunnels longer than the Saint-Gothard (16 918 m); and that road tunnels may reach 20 km to 25 km. (from Author) 967276
Automated surveying speeds construction K. Rabensteiner, Tunnels & Tunnelling, 28(l), 1996, pp 4041. This article describes an integrated tunnel monitoring system which combines modern optical 3D techniques with the latest motor&d surveying instruments. It is particularly applicable in NATM projects. System hardware and software are outlined, and deformed monitoring, profile measuring and control, and setting out are detailed. (J.M.McLaughlin) 967277 New York City subway link-up M. Page, Tunnels & Tunnelling, 28(3), 1996, pp 16-18. Reports on the construction of the 63rd Street Connector subway for the New York City Transit Authority. The project is divided into four major contracts which will connect the 63rd Street subway to the Queens Boulevard-bound subway. The contract details and current state of the works are reviewed. (C.Paice)
967273
967278
Experimental study on failure process of surrounding rocks for excavation openings (in Chinese) Zhao Zhenying, Shuili Xuebao/Journal of Hydraulic Engineering, 12, 1995, pp 23-28. Several model tests for a large underground hydroplant are presented. The state of secondary strain, failure process and safey factor in rock surrounding excavation openings have been studied with geological structure being considered. (English summary)
Tunnels
High pressure jet grouting at Islais Creek ANON, Tunnels & Tunnelling, 28(l), 1996, p 35. Describes the high pressure jet grouting technique used as an alternative to compressed air to support a shield driven tunnel face on a sewer system upgrading program in the San Francisco area. The project includes excavation of two sewer tunnels in soft organic silty clay. Both tunnels will have a final steel lining. The Rodinjet 1 high pressure jet grouted columns were used to pre-treat the ground in and around the tunnel excavation, providing temporary tunnel support and face stability. This is the first example of full face grouted tunnel treatment in North America. (J.M.McLaughlin)
967274
967279
World class tunnelling P. Hartley, Tunnels & Tunnelling, 27(12), 1995, pp 36-44. A review of major tunnelling projects worldwide. European projects described include the immersed tube tunnel under the River Lee at Cork in the Republic of Ireland; the 3.5 km long Oresund immersed tube tunnel which forms part of the link between Denmark and Sweden; a water supply tunnel for Cadiz in Spain; the Milan and Rome metros in Italy; NATM tunnelling on the Munich Metro which suffered a collapse recently; UK progress on the London Jubilee Line Extension and the Heathrow Express Tunnels are detailed. Tunnelling activities in the Americas includes: the Los Angeles Metro; a 90 km water tunnel for New York City, and urban metro tunnelling projects in several Latin American countries. In the Pacific Rim, progress on several underground rail projects, Hona Kone’s Western Harbour Crossine six-lane immersed tube;oad tinnel; China’s Three Gorges Hydroelectric power project; and the Blue Mountains sewage transfer scheme in Austria are reviewed. (J.M.McLaughlin)
Terminal condition P. Wheeler, Ground Engineering, 29(l), 1996, pp 14-16. Fifteen months after the collapse of the Heathrow Express Central Terminal Area, work is progressing at full speed on the rescue operations. Construction of the CTA within a 60 m diameter secant piled cofferdam and changes in tunnelling strategy should bring project completion back to within six months of the original programme. (Author)
967275
Major road tunnel projects - how far can we go? M. Marec, Tunnelling & Underground Space Technology, 11(l), 1996, pp 21-26. Considers the main length-limiting elements for road tunnels. Each of the following factors is discussed in terms of the effect of it on road tunnel length: 1) Heading face distance; 2) Site ventilation; 3) Heating-up of the ground; 4) Soil pressures; 5) Risk of inflows under pressure; 6) Deep level geological reconnaissance constraints; 7) Time required for construction; and 8) Construction costs. Other factors are specific to road tunnels; 9) Ventilation and 10) Driver claustrophobia and boredom. the latter factor may eventually be the more restrictive. The conclusion is that none of these factors in and
967280
Tunnel vision D. Parker, New Civil Engineer (NCE), 1166, 1996, p 12. This short article discusses the elaborate settlement monitoring program which was established along the length of London’s Jubilee Line Extension tunnels between Green Park and Waterloo. The monitoring team installed over 2000 electrolevels and set up a network of 7000 reference points along the route, including 9 monitors on the bottom of a basement swimming pool in Pall Mall. With hindsight the engineers have concluded that the monitoring exercise was somewhat over the top. (C.Paice) 967281 Engineers face up to the bogs and tunnels M. Winney, New Civil Engineer (NCE), 1165, 1996, pp 6-7. This article reports on the engineering challenges which face the contractors preparing to bid for the 108 km Channel Tunnel Rail Link. The project will be split into 5 equal value parcels, namely: St Pa&as and its approaches, the London tunnels. Thames vallev to the A2. the whole of the rural section-through Kent, and system wide installation of track, power and signalling. The route of the project and the various engineering aspects along it are reviewed. (C.Paice)
reliability and reliability index of single failure
mode are discussed under u-constraint level. The same are then derived using a fuzzy random approach. (from English summary) 967263 A structural reliability algorithm (in Chinese)
analysis
method based on genetic
Zhao Yangang & Jiang Jinren, Earthquake Engineering & Engineering Vibration, 15(3), 1995, pp 45-58. Presents a genetic algorithm for searching the most likely failure point which is not limited by restrictive assumptions about search space, such as continuity or existence of derivatives. The workings of genetic algorithm in structural reliability are investigated and three intellectual faculties are introduced to improve the search process. From examples it is found that the problems in deciding the length of strings can be effectively improved. (from English summary) 967264 Stochastic response analysis of tall building structures with added hysteretic energy dissipation devices (in Chinese) Tian Qianli, A. K. H. Kwan & Y. K. Cheung, Earthquake Engineering & Engineering Vibration, 15(2), 1995, pp 109117.
An approximate method is presented to analyse tall building structures with added hysteretic energy dissipation devices. The structure is modeled as a cantilever beam on hysteretic nonlinear supports. Its governing equation is derived by using Ritz method and linearized in each iterative step, based on an equivalent linearized method. This method is relatively inexpensive in computation and therefore allows assessment of effects of various parameters on responses. Results show that the use of wire-cable isoslator combined with viscoelastic damping layers is a good example of energy dissipation device, so it is recommended as a novel aseismic mechanism. (English summary) 967265 The singular solutions of axisymmetric elastodynamic problem for multilayered halfspace by means of transfer matrix (in Chinese) Meng Fanshun, Guo Haiyan & Yie Tianqi, Earthquake Engineering & Engineering Vibration, 15(2), 1995, pp 44-51. A singular solution of the axisymmetric elastodynamic problem for the multilayered halfspace due to any axisymmetrical dynamic load acting within layered media is derived in the time domain with the aid of Laplace-Hankel mixed transforms and transfer matrix method. This method is clear and the corresponding formulas simple and convenient. An example is presented. (from English summary) 967266 An introduction to the method and analytical program for prediction of earthquake damage of rectangular reinforced concrete cistern (in Chinese) Guo Endong & Feng Qimin, Earthquake Engineering & Engineering Vibration, 15(2), 1995, pp l-9.
A method and an analytical program for prediction of earthquake damage to rectangular reinforced cisterns are presented. The results of earthquake damage prediction of two cisterns are obtained using this method and program. The conclusion is that the underground cistern has better earthquake resistance compared with ground cisterns. (from English summary) 967267 Analytical solutions of viscoelastic multilayered halfplane problem to an arbitrary buried source (in Chinese) Meng Fanshun, Yang Dehai &Wang Youlong, Earthquake Engineering & Engineering Vibration, 15(3), 1995, pp 32-37.
Assuming the 2-dimensional plan strain state, analytical solutions of viscoelastic multilayered halfplane problem to an arbitrary buried source are derived with the aid of Fourier-
STRESS
323A
transforms and transfer matrix me presented. (from English summary)
EXCAVATIONS Genera 967268 The use of underground space in Hong A. W. Malone, Tunneiling & Undergroun 1 l(l), 1996, pp 57-64.
e Techno1ogy,
In 1991, the Hong Kong Government adopted a policy of encouraging development in rock caverns, where such development is appropriate. The underground aption has recently been selected for certain facilities considered environmentally unattractive for surface placement. The aper discusses technical aspects of some of the cavern schemes currently under construction. It also traces the history of cavern usage in Hong Kong and describes the Hong Kong Geotechnical Engineering Office’s study of the potential use of underground space in Hong Kong. (Author)
Geological
factors
967269 A soft layer to control soil arching abode a basic
A. N. Dancygier
& D. Z. Yankelevsky,
~~~~~~er~ng
Structures, 18(5), 1996, pp 378-386.
The possibility of controlling arching by application of a soft layer in the soil above a roof is investigated and described. New definitions, that better describe various aspects of the phenomenon, are proposed, and used in a quantitative analysis of the problem. The effects of the soft layer are discussed and it is shown that there is an optimal length of the soft layer that yields minimal loading on the buried roof. (from Authors) 967270 Modelling of ground movements layered ground R. J. Grant & R. N. Taylor, Ground ~~gi~eeri~~, 29(l), 1996, p 29. A project is described in which a 2D or plane strain analogue is being used to study the effect of tunnelling in layered ground using both physical model tests and numerical analysis. The main objective of the work is to improve methods of estimating surface and subsurface movements caused by tunnelling in layered ground. Analysis of the various test data indicates the following: surface and subsurface settlement troughs within both the sand and the clay are reasonably represented by the commonly assumed Gaussian distribution; the settlement trough width is independent of volume loss due to tunnel excavation; the width of the subsurface settlement troughs tends to be greater than predictions made using current practice. (from
Stresses around openi 967271 The effect of a nonlinear Mohr-Couliomb crit stresses and plastic deformation n poorly consolidated permeable m Y. Wang, International Journal of eeb~~~c~& Mining
Sciences, 33(2), 1996, pp 197-203. A closed-form solution for the stresses near a circuiar opening is presented. A nonlinear MC criterion is introduced which is used to govern the permissible stresses near opening. Poroelastic medium is assumed for those regions where stress state is within the criterion envelop and a perfects plastic medium is assumed for the regions in which such a criterion is exceeded. Only a steady state flow is considered which can be decoupled from the deformation. According to the calcula-
324A
EXCAVATIONSTUNNELS
tion the stresses by a linear MC criterion are overestimated, but the plastic radius is underestimated. Both the effective tangential stress and the plastic radius can be significantly affected by pore pressure penetration. It is concluded that the pore pressure penetration effect on the stress analyses and plastic zone prediction must be incorporated. (Author) 967272 The use of stress-strength relationships in the assessment of tunnel stability R. Bhasin & E. Grimstad, Tunnelling & Underground Space Technology, 1l(l), 1996, pp 93-98. A method of predicting probable ground behaviour considering stress-strength relationships is presented. The influence of overburden pressure and rock mass strength are considered in forecasting stability problems in tunnels. In particular, squeezing, spalling and loosening of the rock mass in tunnels constructed through the complex geological set-up of the Himalayas have been analysed. A new Q-system correlation which takes into account the dimension of an opening is suggested for evaluating support pressures in squeezing ground. (from Authors)
Excavation
failure mechanisms
of itself would prevent the construction of road tunnels longer than the Saint-Gothard (16 918 m); and that road tunnels may reach 20 km to 25 km. (from Author) 967276
Automated surveying speeds construction K. Rabensteiner, Tunnels & Tunnelling, 28(l), 1996, pp 4041. This article describes an integrated tunnel monitoring system which combines modern optical 3D techniques with the latest motor&d surveying instruments. It is particularly applicable in NATM projects. System hardware and software are outlined, and deformed monitoring, profile measuring and control, and setting out are detailed. (J.M.McLaughlin) 967277 New York City subway link-up M. Page, Tunnels & Tunnelling, 28(3), 1996, pp 16-18. Reports on the construction of the 63rd Street Connector subway for the New York City Transit Authority. The project is divided into four major contracts which will connect the 63rd Street subway to the Queens Boulevard-bound subway. The contract details and current state of the works are reviewed. (C.Paice)
967273
967278
Experimental study on failure process of surrounding rocks for excavation openings (in Chinese) Zhao Zhenying, Shuili Xuebao/Journal of Hydraulic Engineering, 12, 1995, pp 23-28. Several model tests for a large underground hydroplant are presented. The state of secondary strain, failure process and safey factor in rock surrounding excavation openings have been studied with geological structure being considered. (English summary)
Tunnels
High pressure jet grouting at Islais Creek ANON, Tunnels & Tunnelling, 28(l), 1996, p 35. Describes the high pressure jet grouting technique used as an alternative to compressed air to support a shield driven tunnel face on a sewer system upgrading program in the San Francisco area. The project includes excavation of two sewer tunnels in soft organic silty clay. Both tunnels will have a final steel lining. The Rodinjet 1 high pressure jet grouted columns were used to pre-treat the ground in and around the tunnel excavation, providing temporary tunnel support and face stability. This is the first example of full face grouted tunnel treatment in North America. (J.M.McLaughlin)
967274
967279
World class tunnelling P. Hartley, Tunnels & Tunnelling, 27(12), 1995, pp 36-44. A review of major tunnelling projects worldwide. European projects described include the immersed tube tunnel under the River Lee at Cork in the Republic of Ireland; the 3.5 km long Oresund immersed tube tunnel which forms part of the link between Denmark and Sweden; a water supply tunnel for Cadiz in Spain; the Milan and Rome metros in Italy; NATM tunnelling on the Munich Metro which suffered a collapse recently; UK progress on the London Jubilee Line Extension and the Heathrow Express Tunnels are detailed. Tunnelling activities in the Americas includes: the Los Angeles Metro; a 90 km water tunnel for New York City, and urban metro tunnelling projects in several Latin American countries. In the Pacific Rim, progress on several underground rail projects, Hona Kone’s Western Harbour Crossine six-lane immersed tube;oad tinnel; China’s Three Gorges Hydroelectric power project; and the Blue Mountains sewage transfer scheme in Austria are reviewed. (J.M.McLaughlin)
Terminal condition P. Wheeler, Ground Engineering, 29(l), 1996, pp 14-16. Fifteen months after the collapse of the Heathrow Express Central Terminal Area, work is progressing at full speed on the rescue operations. Construction of the CTA within a 60 m diameter secant piled cofferdam and changes in tunnelling strategy should bring project completion back to within six months of the original programme. (Author)
967275
Major road tunnel projects - how far can we go? M. Marec, Tunnelling & Underground Space Technology, 11(l), 1996, pp 21-26. Considers the main length-limiting elements for road tunnels. Each of the following factors is discussed in terms of the effect of it on road tunnel length: 1) Heading face distance; 2) Site ventilation; 3) Heating-up of the ground; 4) Soil pressures; 5) Risk of inflows under pressure; 6) Deep level geological reconnaissance constraints; 7) Time required for construction; and 8) Construction costs. Other factors are specific to road tunnels; 9) Ventilation and 10) Driver claustrophobia and boredom. the latter factor may eventually be the more restrictive. The conclusion is that none of these factors in and
967280
Tunnel vision D. Parker, New Civil Engineer (NCE), 1166, 1996, p 12. This short article discusses the elaborate settlement monitoring program which was established along the length of London’s Jubilee Line Extension tunnels between Green Park and Waterloo. The monitoring team installed over 2000 electrolevels and set up a network of 7000 reference points along the route, including 9 monitors on the bottom of a basement swimming pool in Pall Mall. With hindsight the engineers have concluded that the monitoring exercise was somewhat over the top. (C.Paice) 967281 Engineers face up to the bogs and tunnels M. Winney, New Civil Engineer (NCE), 1165, 1996, pp 6-7. This article reports on the engineering challenges which face the contractors preparing to bid for the 108 km Channel Tunnel Rail Link. The project will be split into 5 equal value parcels, namely: St Pa&as and its approaches, the London tunnels. Thames vallev to the A2. the whole of the rural section-through Kent, and system wide installation of track, power and signalling. The route of the project and the various engineering aspects along it are reviewed. (C.Paice)