- Email: [email protected]
Study on prevention of frost heave with reinforcement (in Chinese)
368A
REINFORCEMENTEARTH
Machine excavation 968249 The determination of rock material properties to predict the performance of machine excavation in tunnels C. D. Arthur, Quarterly Journal of Engineering Geology, 29(l), 1996, pp 67-81. Au extensive suite of laboratory tests is combined with a comprehensive literature search in order to investigate the interrelationships between some commonly cited rock parameters. Rock material strength and hardness, with regard to common tunnel excavation techniques is found to be a combination of shear and tensile strength and can respectively be designated as cutting strength and abrasivity. An overall classification system is proposed which incorporates these parameters into an unambiguous notation in order to clarify test data and facilitate interpretation. An incremental approach for rock testing programmes is constructed in the form of a flow chart. The model proposes how the efficiency of current test programmes can be improved. (from Author) 968250 Improving eartkmoving estimating by more realistic knowledge J. Christian 8c Tian Xing Xie, Canadian Journal of Civil Engineering, 23(l), 1996, pp 250-259. Inaccuracies are often built into earthmoving estimates by the fairly sweeping assumptions that are made during the estimating process. The factors that affect the performance of machines are discussed, including the common types of earthmoving operations. The importance of haul distance in determining which type of equipment should be used is also considered. The selection of equipment and estimation of costs for earthmoving depend heavily on human experience. The means of eliciting human experience are described in detial. Because of this reliance on human experience, a prototype knowledge-based expert system was developed using a shell program. The system is able to select the most appropriate fleet of machines, and estimate the cost, for use as a decision support system in planning an earthmoving operation. (from Authors)
ROCK AND SOIL REINFORCEMENT AND SUPPORT Bolts and anchors 968251 Instrumentation for monitoring the dynamic and static behaviour of rock bolts in tunnels A. A. Rodger, G. S. Littlejohn, H. Xu & D. C. Holland, Proceedings - ICE: Geotechnical Engineering, 119(3), 1996, pp 146-155. The field component of the research has comprised an investigation of the instantaneous and long-term response of rock bolts when subjected to blasting at two tunnel construction sites in north Wales, namely Penmaenbach and Pen y Clip. This paper describes the field instrumentation systems devised for the project including the transducers, signal conditioning and recording equipment and the methods for analysis of signals. (from Authors)
Shotcrete 968252 Three year research alms to throw light on sprayed concrete linings ANON, Ground Engineering, 29(3), 1996, p 6. Mott MacDonald and Surrey University are collaborating on new research to enhance understanding of the support interaction between sprayed concrete tunnel linings and soft
& GEOSYNTHETICS ground - and to develop analysis and design methods which reflect this interaction more accurately than current conventional structural analyses. The three-year project centres on obtaining high quality monitoring data to be used for the development of analysis and design methods. One aspect to be investigated is the monitoring and measuring of stresses in sprayed concrete linings for the station tunnels being built at Heathrow’s Terminal 4 as part of the Heathrow Express rail link. (Author)
Direct rock support methods 968253 FulI scale testing of steel arck tunnel supports U. H. Khan, H. S. Mitri & D. Jones, International Journal of Rock Mechanics & Mining Sciences, 33(3), 1996, pp 219-232. The arches, made from RSJ, were tested by jacking the arch legs against blocking points located along the crown of the arch. The number as well as the positions of the blocking points were varied in an effort to simulate various roof loading conditions and constraints. A nonlinear finite element modelting technique was applied to simulate the tested arch supports. Comparison of the ultimate strengths obtained from numerical predictions and experimental results show good agreement. It is found that increasing the number of blocking points causes a substantial gain in the load carrying capacity of the arch support. (from Authors)
Reinforced earth and geosynthetics 968254
A geogrld reinforced embankment on peat over organic silt: a case history R. K. Rowe 8c B. L. J. Mylleville, Can&an Geotechnical Journal, 33(l), 1996, pp 106-122. The behaviour of an instrumented section of a full-scale geogrid reinforced embankment constructed on a very soft deposit of peat overlying organic silt is examined. The results of field monitoring are reported together with engineering properties of the soils obtained from laboratory tests. The bchaviour was analyzed using the finite element method, and the calculated performance is shown to be in good agreement with that observed. (Authors) 968255 Full-scale field experimentation of a new technique for protecting mudstone slopes, Taiwan D. H. Lee, K. G. Tien & C. H. Juang, Engineering Geology, 42(l), 1996, pp 51-63. The new technique involves the use of two types of waterproof materials. One material is ashpalt, and the other is geotextile sheets coated with asphalt. Engineering details of the treatment are presented in this paper. Based on the field observations and measurements, the treated slopes do not show any signs of significant erosion and movement. Thus, the new technique is demonstrated to be effective. (from Authors) 968256 Study on prevention of frost heave with reinforcement (in Chinese) Chen Lun, Guo Ruiping, Li Guangxin & Gao Yuan, Shuili XuebaojJournal of Hydraulic Engineering, 3, 1996, pp 84-88. A series of laboratory frost tests were performed in order to study the application of restraining pressure to prevent frost heave of soils. Results show that, to keep frost heave displacement small enough to prevent structural damage it is not necessary to apply the restraining pressure up to the suspended pressure. The application of reinforcement or suitable design of structure can provide an restraining pressure to greatly reduce the frost-heaving displacement of the structure. (from English summary)
REINFORCEMENTEARTH
Machine excavation 968249 The determination of rock material properties to predict the performance of machine excavation in tunnels C. D. Arthur, Quarterly Journal of Engineering Geology, 29(l), 1996, pp 67-81. Au extensive suite of laboratory tests is combined with a comprehensive literature search in order to investigate the interrelationships between some commonly cited rock parameters. Rock material strength and hardness, with regard to common tunnel excavation techniques is found to be a combination of shear and tensile strength and can respectively be designated as cutting strength and abrasivity. An overall classification system is proposed which incorporates these parameters into an unambiguous notation in order to clarify test data and facilitate interpretation. An incremental approach for rock testing programmes is constructed in the form of a flow chart. The model proposes how the efficiency of current test programmes can be improved. (from Author) 968250 Improving eartkmoving estimating by more realistic knowledge J. Christian 8c Tian Xing Xie, Canadian Journal of Civil Engineering, 23(l), 1996, pp 250-259. Inaccuracies are often built into earthmoving estimates by the fairly sweeping assumptions that are made during the estimating process. The factors that affect the performance of machines are discussed, including the common types of earthmoving operations. The importance of haul distance in determining which type of equipment should be used is also considered. The selection of equipment and estimation of costs for earthmoving depend heavily on human experience. The means of eliciting human experience are described in detial. Because of this reliance on human experience, a prototype knowledge-based expert system was developed using a shell program. The system is able to select the most appropriate fleet of machines, and estimate the cost, for use as a decision support system in planning an earthmoving operation. (from Authors)
ROCK AND SOIL REINFORCEMENT AND SUPPORT Bolts and anchors 968251 Instrumentation for monitoring the dynamic and static behaviour of rock bolts in tunnels A. A. Rodger, G. S. Littlejohn, H. Xu & D. C. Holland, Proceedings - ICE: Geotechnical Engineering, 119(3), 1996, pp 146-155. The field component of the research has comprised an investigation of the instantaneous and long-term response of rock bolts when subjected to blasting at two tunnel construction sites in north Wales, namely Penmaenbach and Pen y Clip. This paper describes the field instrumentation systems devised for the project including the transducers, signal conditioning and recording equipment and the methods for analysis of signals. (from Authors)
Shotcrete 968252 Three year research alms to throw light on sprayed concrete linings ANON, Ground Engineering, 29(3), 1996, p 6. Mott MacDonald and Surrey University are collaborating on new research to enhance understanding of the support interaction between sprayed concrete tunnel linings and soft
& GEOSYNTHETICS ground - and to develop analysis and design methods which reflect this interaction more accurately than current conventional structural analyses. The three-year project centres on obtaining high quality monitoring data to be used for the development of analysis and design methods. One aspect to be investigated is the monitoring and measuring of stresses in sprayed concrete linings for the station tunnels being built at Heathrow’s Terminal 4 as part of the Heathrow Express rail link. (Author)
Direct rock support methods 968253 FulI scale testing of steel arck tunnel supports U. H. Khan, H. S. Mitri & D. Jones, International Journal of Rock Mechanics & Mining Sciences, 33(3), 1996, pp 219-232. The arches, made from RSJ, were tested by jacking the arch legs against blocking points located along the crown of the arch. The number as well as the positions of the blocking points were varied in an effort to simulate various roof loading conditions and constraints. A nonlinear finite element modelting technique was applied to simulate the tested arch supports. Comparison of the ultimate strengths obtained from numerical predictions and experimental results show good agreement. It is found that increasing the number of blocking points causes a substantial gain in the load carrying capacity of the arch support. (from Authors)
Reinforced earth and geosynthetics 968254
A geogrld reinforced embankment on peat over organic silt: a case history R. K. Rowe 8c B. L. J. Mylleville, Can&an Geotechnical Journal, 33(l), 1996, pp 106-122. The behaviour of an instrumented section of a full-scale geogrid reinforced embankment constructed on a very soft deposit of peat overlying organic silt is examined. The results of field monitoring are reported together with engineering properties of the soils obtained from laboratory tests. The bchaviour was analyzed using the finite element method, and the calculated performance is shown to be in good agreement with that observed. (Authors) 968255 Full-scale field experimentation of a new technique for protecting mudstone slopes, Taiwan D. H. Lee, K. G. Tien & C. H. Juang, Engineering Geology, 42(l), 1996, pp 51-63. The new technique involves the use of two types of waterproof materials. One material is ashpalt, and the other is geotextile sheets coated with asphalt. Engineering details of the treatment are presented in this paper. Based on the field observations and measurements, the treated slopes do not show any signs of significant erosion and movement. Thus, the new technique is demonstrated to be effective. (from Authors) 968256 Study on prevention of frost heave with reinforcement (in Chinese) Chen Lun, Guo Ruiping, Li Guangxin & Gao Yuan, Shuili XuebaojJournal of Hydraulic Engineering, 3, 1996, pp 84-88. A series of laboratory frost tests were performed in order to study the application of restraining pressure to prevent frost heave of soils. Results show that, to keep frost heave displacement small enough to prevent structural damage it is not necessary to apply the restraining pressure up to the suspended pressure. The application of reinforcement or suitable design of structure can provide an restraining pressure to greatly reduce the frost-heaving displacement of the structure. (from English summary)