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Instability and ill-posedness in the deformation of granular materials
35A seen in weak rock zones or special or enlarged intersections. Results of monitoring during a nearby earthquake of magnitude 5.4 on the Richter scale are also presented.
911271 Cordless geo data-link Teal, D L E Proc Conference on Instrumentation in Geatedudccd Engineering, Nottingham, 3-5 April 1989 I/1, P343-354. Publ London: Thomas Telford, 1989 The traditional 'umbilical' cable data link to monitoring systems has faults in liability to damage, disruptive installation, and costs. To remove these drawbacks, cordless, battery powered, microprocessor controlled instrumentation has been developed. Hardware is described, and initial field trials and future developments discussed.
911272 Trar~lncer for measuring normal and shear stresses Rowlands, G O; Deipak, R; Wersching, S N Proc Conference on Instrumentation in Geotecludcal Engineering, Nottingham, 3-J April 1989 I/1, P355-374. Publ London: Thomas Telford, 1989 A simple boundary stress transducer for measurement of shear and radial stresses on a pile shaft is presented. It is relatively easy to manufacture and requires only 8 strain gauges to monitor the readings. Calibration procedures and optimisation of design by finite element analysis are described. Installation on the pile shaft and typical test output are described.
911273 Long term monitoring of surface movements of reservoirs by surveying techniques Ashkenazi, V; Dodson, A H; Jones, D E B; Samson, N Proc Conference on Instrumentation in Geoeeclmical Engineering, Nottingham, 3-5 April 1989 VI, P375-385. Publ London: Thomas Telford, 1989 Geodetic networks to provide information about the embankments and underlying strata of the Queen Mother reservoir at Datchet are described. The structure is formed largely of ballast with a clay core keyed to the underlying London Clay. Precision theodolites (some self-recording), electronic distance measuring instruments, and spirit levels are installed. Statistical analysis of data allows positions to be determined with accuracy of millimetres or less. Long term trends have been determined.
9 ! i 274 Instrumentation for highway works - obtaining value for money Greenwood, J R; Herrick, G W Proc Conference on Instrumentation in Geotechnical Engineering, Nottinghmm, 3-5 April 1989 I/1, P387-398. Publ London: Thomas Telford, 1989 Typical instrumentation used by the DoT Eastern Region for construction control, design control, checking of design assumptions, or research and feedback is described. Installation problems, damage resistance, reliability, and limitations in monitoring settlements, groundwater, and structures are discussed, with particular reference to cost effectiveness.
911275
Rock nt~h ra~ investigation in post pillar cut and fill mining and interior support for mxbilimtion Durra, S K; Lahiri, D Proc International Symposium on Underground Engineering, New Delhi, 14-17 April 1988 VI. P351-363. Publ Rotterdam: A A Balkema, 1988 Cut and fill mining is generally used in narrow orebodies, but geological and geotechnical information collated through site investigation has made it possible to apply this technique to mine wide deposits. Through numerical modelling techniques, stress induced failure criteria and stability parameters can be derived. Both support techniques and instruments used in monitoring the ground around excavations are outlined. Numerical modelling and geomechanical classifications are also discussed.
Analysis Techniques and Design Methods See: 911150, 911345
Stress analysis See also: 911068, 911123, 911124. 911125, 911193, 911338, 911379, 911276 Homogeneous and Iocaiised deformation in granular materials: a mechanistic model Chandler, H W lnt J Engng Sci t/28, N8. 1990, P719-734 A model for granular flow is presented which is an extension of critical state soil mechanics, using both local deformation at grain contacts and rearrangement of particles to account jointly for bulk deformation. It is used to simulate drained and undrained triaxial tests, and output is in qualitative agreement with laboratory results. Some tests are simulated in which shear bands can occur. The failure surface predicted is similar to that of the Mohr-Coulomb criterion, whilst using a yield surface with circular cross-section on the plane of constant pressure. 911277 Instability and ill-poseduess in the deformation of granular materials Schaeffer, D G lat J Nnm Anal Meth Geomcch 1/14, N4, May 1990, P253278 Linear stability analysis of the partial differential equations of granular flow is presented. The constitutive models include elastic effects, non-associated flow, and shear strain hardening. Conditions for the equations to be stable and well posed are evaluated. Two different types of instability are found. Parameters in constitutive equations govern which appears first. For one, shear bands occur in an approximately homogeneous specimen, for the other they are preceded by inhomogeneous deformation. Comparisons with experimental results are discussed.
~) 1991 Pergamon Press plc. Reproduction not permitted
911271 Cordless geo data-link Teal, D L E Proc Conference on Instrumentation in Geatedudccd Engineering, Nottingham, 3-5 April 1989 I/1, P343-354. Publ London: Thomas Telford, 1989 The traditional 'umbilical' cable data link to monitoring systems has faults in liability to damage, disruptive installation, and costs. To remove these drawbacks, cordless, battery powered, microprocessor controlled instrumentation has been developed. Hardware is described, and initial field trials and future developments discussed.
911272 Trar~lncer for measuring normal and shear stresses Rowlands, G O; Deipak, R; Wersching, S N Proc Conference on Instrumentation in Geotecludcal Engineering, Nottingham, 3-J April 1989 I/1, P355-374. Publ London: Thomas Telford, 1989 A simple boundary stress transducer for measurement of shear and radial stresses on a pile shaft is presented. It is relatively easy to manufacture and requires only 8 strain gauges to monitor the readings. Calibration procedures and optimisation of design by finite element analysis are described. Installation on the pile shaft and typical test output are described.
911273 Long term monitoring of surface movements of reservoirs by surveying techniques Ashkenazi, V; Dodson, A H; Jones, D E B; Samson, N Proc Conference on Instrumentation in Geoeeclmical Engineering, Nottingham, 3-5 April 1989 VI, P375-385. Publ London: Thomas Telford, 1989 Geodetic networks to provide information about the embankments and underlying strata of the Queen Mother reservoir at Datchet are described. The structure is formed largely of ballast with a clay core keyed to the underlying London Clay. Precision theodolites (some self-recording), electronic distance measuring instruments, and spirit levels are installed. Statistical analysis of data allows positions to be determined with accuracy of millimetres or less. Long term trends have been determined.
9 ! i 274 Instrumentation for highway works - obtaining value for money Greenwood, J R; Herrick, G W Proc Conference on Instrumentation in Geotechnical Engineering, Nottinghmm, 3-5 April 1989 I/1, P387-398. Publ London: Thomas Telford, 1989 Typical instrumentation used by the DoT Eastern Region for construction control, design control, checking of design assumptions, or research and feedback is described. Installation problems, damage resistance, reliability, and limitations in monitoring settlements, groundwater, and structures are discussed, with particular reference to cost effectiveness.
911275
Rock nt~h ra~ investigation in post pillar cut and fill mining and interior support for mxbilimtion Durra, S K; Lahiri, D Proc International Symposium on Underground Engineering, New Delhi, 14-17 April 1988 VI. P351-363. Publ Rotterdam: A A Balkema, 1988 Cut and fill mining is generally used in narrow orebodies, but geological and geotechnical information collated through site investigation has made it possible to apply this technique to mine wide deposits. Through numerical modelling techniques, stress induced failure criteria and stability parameters can be derived. Both support techniques and instruments used in monitoring the ground around excavations are outlined. Numerical modelling and geomechanical classifications are also discussed.
Analysis Techniques and Design Methods See: 911150, 911345
Stress analysis See also: 911068, 911123, 911124. 911125, 911193, 911338, 911379, 911276 Homogeneous and Iocaiised deformation in granular materials: a mechanistic model Chandler, H W lnt J Engng Sci t/28, N8. 1990, P719-734 A model for granular flow is presented which is an extension of critical state soil mechanics, using both local deformation at grain contacts and rearrangement of particles to account jointly for bulk deformation. It is used to simulate drained and undrained triaxial tests, and output is in qualitative agreement with laboratory results. Some tests are simulated in which shear bands can occur. The failure surface predicted is similar to that of the Mohr-Coulomb criterion, whilst using a yield surface with circular cross-section on the plane of constant pressure. 911277 Instability and ill-poseduess in the deformation of granular materials Schaeffer, D G lat J Nnm Anal Meth Geomcch 1/14, N4, May 1990, P253278 Linear stability analysis of the partial differential equations of granular flow is presented. The constitutive models include elastic effects, non-associated flow, and shear strain hardening. Conditions for the equations to be stable and well posed are evaluated. Two different types of instability are found. Parameters in constitutive equations govern which appears first. For one, shear bands occur in an approximately homogeneous specimen, for the other they are preceded by inhomogeneous deformation. Comparisons with experimental results are discussed.
~) 1991 Pergamon Press plc. Reproduction not permitted