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Irregular stress-strain and progressive failure
88A
843O64 Determination of the anisotroplc elastic moduli of coal Szwilski, A B int J Rock Mech Min Sci V21, N1, Feb 1984, P3-12 A method that determines the two, mutually orthogonal, effective elastic moduli in the plane perpendicular to a borehole has been developed. The theory relates the radial displacements in a cylindrical borehole to an elastically orthotropic material. A triaxial compression cell capable of loading 300mm coal cubes by means of six steel flatjacks was used. Measurement of surface displacements of a centrally drilled borehole were taken using a USBM deformation gauge. The influence of the principal structural features of coal on the elastic behaviour.and other deformational characteristics is discussed. Auth. 843065 Endochronic modeling for shear hysteresis of sand Han-Chin Wu; Jiun-Chyuan Sheu J Geotech Engng Div ASCE VI09, NGT12, Dec 1983, P1539-1550 A version of the endochronic theory for sand is applied to describe the experimental results of a crystal silica No 20 sand under cyclic simple shearing. 843O66 Past consolidation stress estimates in Cretaceous clay Khera, R P; Schulz, H J Geotech Engng Div ASCE VIIO, NGT2, Feb 1984, P189202 Consolidation tests were performed on both undisturbed and remoulded specimens of Anderton clay and the soil fabric was studied by X-ray diffraction and scanning electron microscopy. It is concluded that: (1) the undisturbed overconsolidated soil has greater unrecoverable strain in the lateral direction compared with the vertical; (2) a more realistic estimate of the precompression stress is obtained when the direction of applied stress coincides with that of the higher unrecovered strain; (3) if a highly overconsolidated soil recovers some or all of the unreleased strain whilst in contact with water, it is no longer able to recall the stress history and a lower value of precompression stress is obtained; and (4) it is not possible to predict the behaviour of undisturbed soil from tests on remoulded soil. 843067 Approximate prediction of soil deformation under drainedrepeated loading Yasuhara, K; Yamanouchi, T; Fujiwara, H; Aoto, H; Hirao, K Soils Found 1/23, N2, June 1983, P13-25 Following a simplified law revealed in a series of repeated triaxial compression tests on a compacted sandy soil, a method is introduced for predicting the converged strain of saturated cohesive soils in repeated oedometer tests and drained repeated triaxial compression tests. Diagrams of the load increment ratio and the converged strain plots are presented for the approximate prediction of settlement of soils under repeated loading.
843068 Stress-strain model for granular materials considering mechanism of fabric change Matsuoka, H; Geka, H Soils Found V23. N2, June 1983, P83-97 A new relationship between strains and fabric change of granular materials is derived and by combining it with a relationship between stresses and fabric change, a stress-strain relationship is formulated under two dimensional stress conditions. The concept of'Spatial Mobilized Plane' (SMP) is introduced to extend this relationship to the three dimensional state.
843069 Continuum theory of coupled seepage and motion problem in saturated porous media. Technical note Ichikawa, Y; Kawamoto, T Soils Found V23, N2, June 1983, P165-167 Mass and linear momentum laws are introduced and reduced to a coupled seepage equation assuming the averaged velocity concept, Darcy's law and a coupled equation of motion. Under proper constitutive assumptions, the coupled equations may be solved for both static and dynamic problems. 843070 Development of a strain measurement system for soils and its application to sand around a buried pipe Takagi, N; Nishio, N; Yoneyama, K; Shimamura, K Soils Found V23, N3, Sept 1983, P65-79 A strain measurement system is developed to determine exact strain distributions in soil in model tests using an X-ray technique. The method determines displacements in soils by tracing images of small lead shot recorded on X-ray films. The lead shot are embedded in advance in the soil in a lattice pattern. As an example the method is applied to model tests studying the behaviour of sand around a buried pipe. 843071 Irregular stress-strain and progressive failure Sotiropoulos, E; Cavounidis, S Proc lOth International Conference on Soil Mechanics and Foundation Engineering, Stockholm, 15-19 June 1981 V3. P527-531. Publ Rotterdam: A. A. Balkema, 1981 The stress-strain curves of a sizeable number of samples of an overconsolidated blue marl exhibited irregular behaviour. An important type of irregularity was that the shear stress passed to the softening side of the curve without ever reaching the expected peak shear strength. The possible implications of such behaviour on the mechanism of progressive failure of slopes are examined. Auth. 843072 ln-situ dynamic deformation properties of soft rock masses Ishikawa, K; Miyajima, K; Hibino, S; Fujiwara, Y; Yamagata, M Proc 5th Congress of the International Society for Rock Mechanics, Melbourne, 10-15 April 1983 V1, PA5-AS. Publ Rotterdam: A. A. Balkema, 1983 In situ dynamic loading tests were performed inside a test adit 2.5m x 2.5m at two sites to estimate the deformation bchaviour of foundation rocks during earthquakes. It is concluded that heterogeneous multiple layer rock formations as represented by the weathered granite at site A can be simulated by the elastoplastic model. A composite layer type rock mass as represented by the interbedded layers of mudstone and sandstone at site B can be expressed in terms of the visco-elastic model. 843073 Evaluation of the deformability of anisotropic rock masses from the results of field tests (In German) Kiehl, J R; Wittke, W Proc 5th Congress of the International Society for Rock Mechanics, Melbourne, 10-15 April 1983 VI, PA75-A85. Publ Rotterdam: A. A. Balkema, 1983 Formulae and diagrams for the evaluation of the parameters of anisotropic rock masses from the results of dilatometer and flat jack tests based on analytical and numerical methods are presented. In situ triaxial tests on rock specimens largely isolated from the surrounding rock mass by slots make possible the determination of several parameters from one sample.
843O64 Determination of the anisotroplc elastic moduli of coal Szwilski, A B int J Rock Mech Min Sci V21, N1, Feb 1984, P3-12 A method that determines the two, mutually orthogonal, effective elastic moduli in the plane perpendicular to a borehole has been developed. The theory relates the radial displacements in a cylindrical borehole to an elastically orthotropic material. A triaxial compression cell capable of loading 300mm coal cubes by means of six steel flatjacks was used. Measurement of surface displacements of a centrally drilled borehole were taken using a USBM deformation gauge. The influence of the principal structural features of coal on the elastic behaviour.and other deformational characteristics is discussed. Auth. 843065 Endochronic modeling for shear hysteresis of sand Han-Chin Wu; Jiun-Chyuan Sheu J Geotech Engng Div ASCE VI09, NGT12, Dec 1983, P1539-1550 A version of the endochronic theory for sand is applied to describe the experimental results of a crystal silica No 20 sand under cyclic simple shearing. 843O66 Past consolidation stress estimates in Cretaceous clay Khera, R P; Schulz, H J Geotech Engng Div ASCE VIIO, NGT2, Feb 1984, P189202 Consolidation tests were performed on both undisturbed and remoulded specimens of Anderton clay and the soil fabric was studied by X-ray diffraction and scanning electron microscopy. It is concluded that: (1) the undisturbed overconsolidated soil has greater unrecoverable strain in the lateral direction compared with the vertical; (2) a more realistic estimate of the precompression stress is obtained when the direction of applied stress coincides with that of the higher unrecovered strain; (3) if a highly overconsolidated soil recovers some or all of the unreleased strain whilst in contact with water, it is no longer able to recall the stress history and a lower value of precompression stress is obtained; and (4) it is not possible to predict the behaviour of undisturbed soil from tests on remoulded soil. 843067 Approximate prediction of soil deformation under drainedrepeated loading Yasuhara, K; Yamanouchi, T; Fujiwara, H; Aoto, H; Hirao, K Soils Found 1/23, N2, June 1983, P13-25 Following a simplified law revealed in a series of repeated triaxial compression tests on a compacted sandy soil, a method is introduced for predicting the converged strain of saturated cohesive soils in repeated oedometer tests and drained repeated triaxial compression tests. Diagrams of the load increment ratio and the converged strain plots are presented for the approximate prediction of settlement of soils under repeated loading.
843068 Stress-strain model for granular materials considering mechanism of fabric change Matsuoka, H; Geka, H Soils Found V23. N2, June 1983, P83-97 A new relationship between strains and fabric change of granular materials is derived and by combining it with a relationship between stresses and fabric change, a stress-strain relationship is formulated under two dimensional stress conditions. The concept of'Spatial Mobilized Plane' (SMP) is introduced to extend this relationship to the three dimensional state.
843069 Continuum theory of coupled seepage and motion problem in saturated porous media. Technical note Ichikawa, Y; Kawamoto, T Soils Found V23, N2, June 1983, P165-167 Mass and linear momentum laws are introduced and reduced to a coupled seepage equation assuming the averaged velocity concept, Darcy's law and a coupled equation of motion. Under proper constitutive assumptions, the coupled equations may be solved for both static and dynamic problems. 843070 Development of a strain measurement system for soils and its application to sand around a buried pipe Takagi, N; Nishio, N; Yoneyama, K; Shimamura, K Soils Found V23, N3, Sept 1983, P65-79 A strain measurement system is developed to determine exact strain distributions in soil in model tests using an X-ray technique. The method determines displacements in soils by tracing images of small lead shot recorded on X-ray films. The lead shot are embedded in advance in the soil in a lattice pattern. As an example the method is applied to model tests studying the behaviour of sand around a buried pipe. 843071 Irregular stress-strain and progressive failure Sotiropoulos, E; Cavounidis, S Proc lOth International Conference on Soil Mechanics and Foundation Engineering, Stockholm, 15-19 June 1981 V3. P527-531. Publ Rotterdam: A. A. Balkema, 1981 The stress-strain curves of a sizeable number of samples of an overconsolidated blue marl exhibited irregular behaviour. An important type of irregularity was that the shear stress passed to the softening side of the curve without ever reaching the expected peak shear strength. The possible implications of such behaviour on the mechanism of progressive failure of slopes are examined. Auth. 843072 ln-situ dynamic deformation properties of soft rock masses Ishikawa, K; Miyajima, K; Hibino, S; Fujiwara, Y; Yamagata, M Proc 5th Congress of the International Society for Rock Mechanics, Melbourne, 10-15 April 1983 V1, PA5-AS. Publ Rotterdam: A. A. Balkema, 1983 In situ dynamic loading tests were performed inside a test adit 2.5m x 2.5m at two sites to estimate the deformation bchaviour of foundation rocks during earthquakes. It is concluded that heterogeneous multiple layer rock formations as represented by the weathered granite at site A can be simulated by the elastoplastic model. A composite layer type rock mass as represented by the interbedded layers of mudstone and sandstone at site B can be expressed in terms of the visco-elastic model. 843073 Evaluation of the deformability of anisotropic rock masses from the results of field tests (In German) Kiehl, J R; Wittke, W Proc 5th Congress of the International Society for Rock Mechanics, Melbourne, 10-15 April 1983 VI, PA75-A85. Publ Rotterdam: A. A. Balkema, 1983 Formulae and diagrams for the evaluation of the parameters of anisotropic rock masses from the results of dilatometer and flat jack tests based on analytical and numerical methods are presented. In situ triaxial tests on rock specimens largely isolated from the surrounding rock mass by slots make possible the determination of several parameters from one sample.