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Instrumental reliability at Harvard Square Station
17A
861 ! 28 Some facts about the reliability of vibrating wire instruments Bordes, J J; Debreuille. P J Trans Res Rec NIO04, 1985, P20-27 The use of vibrating wire instruments, in particular strain gauges and pore pressure cells from a single manufacturer, over a 50 year period is reviewed. Durability, survival rates and causes of instrument failure during manufacture, installation and use are discussed. Time stability and ageing of such instruments is examined. Numerous case studies of their use are described. It is concluded that, from the evidence presented, vibrating wire instruments offer a high degree of stability, accuracy and durability.
861129 Instrumental reliability at Harvard Square Station
Analysis Techniques and Design Methods 861132 Computing costs for FEM analysis of foundation engineering problems and possible ways of increasing efficiency Schad, H lnt J Num Anal Meth Geomech V9, N3, May-June 1985, P261-275 The computing times required by several FEM programs are compared. The FEM numerical analysis is split into its constituent parts - hardware, software, element-mesh and element-type, iteration technique and constitutional model - and it is shown that savings of around 20% in computing time can be made at each level. Overall computing time can be reduced by around 10%, making it economic to solve three dimensional problems by FEM.
Rawnsley, R P; Russel, H A; Hansmire, W H Trans Res Rec N1004, 1985, P27-34
Rock block analysis
Expansion of Harvard Square Station, Cambridge, Massachusetts, USA, employed slurry walls (concrete cast in place within slurry filled trenches) for both excavation and final support. Because of proximity of other structures, ground, building and slurry wall movements were measured by a complex monitoring system using inclinometers, extensometers, tiltmeters, load cells, piezometers and strain gauges. The system was designed such that each parameter was measured by more than one instrument, to cover for the use of instrumentation inappropriate for that specific case, and measurements were correlated with constructional activities and geological conditions. The system proved very reliable, and this is concluded to be due to the use of qualified and experienced staff in its design, installation and use.
861133 Reasonable block-supporting structure for open-pit planning model (In Chinese)
861130 Closing remarks on reliability of geotechnical instrumentation Dunnicliff, J Trans Res Rec NlO04, 1985, P46-49 Factors which promote reliability in a monitoring system are briefly reviewed, including simplicity, self-verification, durability, planning, installation, calibration and maintenance. Methods of measuring total stress, pore pressure, load and stress in structural components, and deformations are briefly summarised and the relative reliability with which they may be measured is assessed.
Zhang, Y D Nonferr Met V37, N3, Aug 1985, P1-5 When modelling open pit mines for planning purposes, it is necessary to adopt a suitable block structure to fit with the chosen mathematical model. Different block supporting structures are analysed and compared and recommendations made for their applications. 861134
Mathematical modelling of jointed rock masses Olofsson, T PhD Thesis, Lulea Univ 1985:42 D, 143P A theoretical model of the mechanical behaviour of jointed rock masses is developed using the equivalent material approach, where structural components, intact rock and joints are all assigned continuous properties. The state of the art in rock mass modelling is briefly reviewed and the properties of joints and intact rock examined. An elasto-visco-plastic model for a jointed rock mass is formulated and tested for various values of the material properties and compared with the results of shear box tests. The model is then applied to a tunnelling problem, the displacement around a circular opening in a jointed rock mass.
Stress analysis See also: 861043
861135 Viscoelastic analysis of piles and pile groups 861131 Deformation measurements with non-stationary electronic inclinometers (In German) Mohlenbrink, W Proc 6th National Rock Mechanics Symposium, Aachen, 3-4 April 1985 P195-200. Publ Essen: German Society for Soil Mechanics and Foundation Engineering, 1985 The use of modern measuring techniques, in particular electronic inclinometers, to monitor the deformation of large dams, is described. Distortions may be detected in their early stages using computer aided data acquisition and analysis.
Ahmad, S; Davies, T G; Manolis, G D lnt J Num Anal Meth Geomech vg, N3, May-June 1985, P237-252 The axial and lateral load-displacement response of single piles and pile groups during the secondary consolidation (creep) phase of deformation is obtained by idealizing the soil as a linear viscoelastic material. The boundary element method is used to model the soil half space, and the piles, which are assumed to behave elastically, are idealised as beamcolumns. By using the correspondence principle, the problem is solved in the Laplace transform domain and the final solution by numerical inversion of the transformed data. The salient features of the viscoelastic response are identified in several
861 ! 28 Some facts about the reliability of vibrating wire instruments Bordes, J J; Debreuille. P J Trans Res Rec NIO04, 1985, P20-27 The use of vibrating wire instruments, in particular strain gauges and pore pressure cells from a single manufacturer, over a 50 year period is reviewed. Durability, survival rates and causes of instrument failure during manufacture, installation and use are discussed. Time stability and ageing of such instruments is examined. Numerous case studies of their use are described. It is concluded that, from the evidence presented, vibrating wire instruments offer a high degree of stability, accuracy and durability.
861129 Instrumental reliability at Harvard Square Station
Analysis Techniques and Design Methods 861132 Computing costs for FEM analysis of foundation engineering problems and possible ways of increasing efficiency Schad, H lnt J Num Anal Meth Geomech V9, N3, May-June 1985, P261-275 The computing times required by several FEM programs are compared. The FEM numerical analysis is split into its constituent parts - hardware, software, element-mesh and element-type, iteration technique and constitutional model - and it is shown that savings of around 20% in computing time can be made at each level. Overall computing time can be reduced by around 10%, making it economic to solve three dimensional problems by FEM.
Rawnsley, R P; Russel, H A; Hansmire, W H Trans Res Rec N1004, 1985, P27-34
Rock block analysis
Expansion of Harvard Square Station, Cambridge, Massachusetts, USA, employed slurry walls (concrete cast in place within slurry filled trenches) for both excavation and final support. Because of proximity of other structures, ground, building and slurry wall movements were measured by a complex monitoring system using inclinometers, extensometers, tiltmeters, load cells, piezometers and strain gauges. The system was designed such that each parameter was measured by more than one instrument, to cover for the use of instrumentation inappropriate for that specific case, and measurements were correlated with constructional activities and geological conditions. The system proved very reliable, and this is concluded to be due to the use of qualified and experienced staff in its design, installation and use.
861133 Reasonable block-supporting structure for open-pit planning model (In Chinese)
861130 Closing remarks on reliability of geotechnical instrumentation Dunnicliff, J Trans Res Rec NlO04, 1985, P46-49 Factors which promote reliability in a monitoring system are briefly reviewed, including simplicity, self-verification, durability, planning, installation, calibration and maintenance. Methods of measuring total stress, pore pressure, load and stress in structural components, and deformations are briefly summarised and the relative reliability with which they may be measured is assessed.
Zhang, Y D Nonferr Met V37, N3, Aug 1985, P1-5 When modelling open pit mines for planning purposes, it is necessary to adopt a suitable block structure to fit with the chosen mathematical model. Different block supporting structures are analysed and compared and recommendations made for their applications. 861134
Mathematical modelling of jointed rock masses Olofsson, T PhD Thesis, Lulea Univ 1985:42 D, 143P A theoretical model of the mechanical behaviour of jointed rock masses is developed using the equivalent material approach, where structural components, intact rock and joints are all assigned continuous properties. The state of the art in rock mass modelling is briefly reviewed and the properties of joints and intact rock examined. An elasto-visco-plastic model for a jointed rock mass is formulated and tested for various values of the material properties and compared with the results of shear box tests. The model is then applied to a tunnelling problem, the displacement around a circular opening in a jointed rock mass.
Stress analysis See also: 861043
861135 Viscoelastic analysis of piles and pile groups 861131 Deformation measurements with non-stationary electronic inclinometers (In German) Mohlenbrink, W Proc 6th National Rock Mechanics Symposium, Aachen, 3-4 April 1985 P195-200. Publ Essen: German Society for Soil Mechanics and Foundation Engineering, 1985 The use of modern measuring techniques, in particular electronic inclinometers, to monitor the deformation of large dams, is described. Distortions may be detected in their early stages using computer aided data acquisition and analysis.
Ahmad, S; Davies, T G; Manolis, G D lnt J Num Anal Meth Geomech vg, N3, May-June 1985, P237-252 The axial and lateral load-displacement response of single piles and pile groups during the secondary consolidation (creep) phase of deformation is obtained by idealizing the soil as a linear viscoelastic material. The boundary element method is used to model the soil half space, and the piles, which are assumed to behave elastically, are idealised as beamcolumns. By using the correspondence principle, the problem is solved in the Laplace transform domain and the final solution by numerical inversion of the transformed data. The salient features of the viscoelastic response are identified in several