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Two elastic-plastic soil models for numerical analysis. Technical note
75A
784041 REGRESSION ANALYSIS OF SOIL COMPRESSIBILITY Azzouz, A S; Erizek, R J; Corotis, R B Soils FOumd, VI6, N2, June 1976, i:']-9-29 Statistical techniques are used to analyze amd evaluate experimental data from more than 700 consolidation tests on a large variety of undisturbed soils, add re6ression equations a r e d e v e l o p e d to estimate the eom~cession index and the compression ratio from classification or imdex data. These regression equations are then examined within the framework of a variety of similar, but more restricted, empirical relationships that have been reported by uther investigators. It is found that both the compression imdex amd the compression ratio can be reasonablM well approximated by use of a simgle linear regression model involving only the initial void ratio. Auth. 784042 TWO ELASTIC-PLASTIC SOIL MODELS FOR ~I~MERICAL ANALYSIS. TECHNICAL NOTE Davidson, H L; Chen, W F Soils Found, VI6, N2, June 1976, P43-50 This paper discusses two elastic-plastic soll models - an elastic-perfectly plastic model (extended von Mises model or Erucker-Prager model) amd an elastic-plastlc strain hardening model (Cambridge modal). Both theories incorporate a yield surface or loading surface, which is dependent on the mean normal stress, and on the normality of the deformation rate vector to these surfaces. Analytical forms of stressstrain relationships for these soil models are stated in incr~nental form, suitable for use in nmmerical analysis. Auth. 7~3
TRENEH WALL JACK: AN APPARatUS TO MEASURE THE EQUIVALENT ELASTIC MGDULUS OF SOIL La~rrence, G J L Transport and Road Research Lab supplementary report 347, 1977, 18P The apparatus described can be used to determine the load-deformation characteristics of insitu soil at the side of a trench. The testing procedure is given and results for equivalent modulus of elasticity in a re~oulded cohesive soil compared wlth those obtained from undrained triaxial tests. The values are in reasonable agreement, but results for the trench wall Jack are more consistent. The study relates to the structural design of buried, flexible pipelines. Avail : TRRL, 01d Wokinghem Road, Crowthcrne, Berks, UK
7~0~
DETERMINATION OF THE ROCK PROPERTIES THAT ARE MEASURED BY CYLINDRICAL PRESSURE CELL TESTS IN BOR~OLES Miller, R J; Duvall, W I; Wang, F D USBM 0FR 82-77, 0c% 1977, 47P Investigates the validity Of the ass~mptlon of complete pressure transfer through the s ~ l i p r e n e s l e e v e o f t h e CSM c e l l , a n d what e f f e c t r o c k properties have on the determination of deformation modulus by this cell. The feasibility of using inclusion geges in the sleeve to measure bmrehole dilatation directly was also studied. Theoretical analysis and practical tests led/cared that pressure transfer should be essentially complete, irdependent of the relative stiffness of the cylinder. A successfuX technique was developed for holding the gages in the
sleeve, am~ suggestion ma~e fcr for solvizg t~ ~roblems of too high strain o b s e r v e d in the gages. It was concluded that the use of inclu~ gages offered a faster, mc~e accurate tech~iq~ for obtalni~g defc~mation modulus in situ. Avail: NTIS, Springfield, Va, 22161, USA
(PB 266 829/AS) 784045 FABRICS AND THEIR EFFECT ON THE DEFOF~4ATION ~qqAVIOUR OF SAND Oda, M Saitama Univ, Del:~ o f Foundation EDgineerimg report (special issue), 1976, 59P Analyses 'derived properties' of sand such as shear stremgth, deformation modulus and permeability in terms of the following properties of the ir~llvidual particles: mineralogy, size, shape, spatial arrangement of particles and voids, ard also water content. Discusses furda men~al properties, fabric, effect of initial fabric on the triaxial compression test, and microscopic observation of deformation mechani in the triaxial compression test. Avail: Faculty of Emgineering, Saitama Univ, Urawa, Saitama, Japan
Time dependent behaviour 784046 CHEEP DEFORMATION OF CLAYS Wu, T H; E1 Refal, A N A A; AsU, J R J Geotech Engmg Div ASCE, V104, NGT1, Jan 1978, P61-76 Stress-strain-time behaviour was studied in several clay soils by drained triaxial tests a creep law was derived. The effects of incremental loadir~, anisctropic consolidation plane strain and simple shear were also investigated. The measured stress-strain-time relat: ship was used to compute displacements of an cavation near Cleveland and the results compared with field measurements. The final displacements were in reasonable agreement, but the computed creep rate is much smaller than t~ measured values. 784047 T~ME-DEPENDEN~ MULTILAMINATE MODEL OF ROCKS. A NUMERICAL STUDY OF DEFORMATION AND FAILURE OF ROCK MASSES Zienkiewicz, 0 C; Pande, G N Int J Num Anal Meth Geomech, V1, N3, July-Se]
1977, P219-247 A ne~ model for rocks and rock-Eke material with multiple planes of weakness is ~roposed. The behaviour of the assembly applies tensile and Mohr-Coulomb shear limits on each such pl~ with possible strain dependence of frictional properties. The visco-plastic algorithm which allows the incorporation of time effects is used to obtain static solutions. The model is illustrated by applications to stability of rc~ slopes and behavlour of tunnels. A ~neralizat~ of the model to include arbitrary threa-dimensional distribution of laminae in 'quasi-pla~ strain' is included. The effect of various flo~ rules adolf6ed for plastic straining is indicate Auth.
784041 REGRESSION ANALYSIS OF SOIL COMPRESSIBILITY Azzouz, A S; Erizek, R J; Corotis, R B Soils FOumd, VI6, N2, June 1976, i:']-9-29 Statistical techniques are used to analyze amd evaluate experimental data from more than 700 consolidation tests on a large variety of undisturbed soils, add re6ression equations a r e d e v e l o p e d to estimate the eom~cession index and the compression ratio from classification or imdex data. These regression equations are then examined within the framework of a variety of similar, but more restricted, empirical relationships that have been reported by uther investigators. It is found that both the compression imdex amd the compression ratio can be reasonablM well approximated by use of a simgle linear regression model involving only the initial void ratio. Auth. 784042 TWO ELASTIC-PLASTIC SOIL MODELS FOR ~I~MERICAL ANALYSIS. TECHNICAL NOTE Davidson, H L; Chen, W F Soils Found, VI6, N2, June 1976, P43-50 This paper discusses two elastic-plastic soll models - an elastic-perfectly plastic model (extended von Mises model or Erucker-Prager model) amd an elastic-plastlc strain hardening model (Cambridge modal). Both theories incorporate a yield surface or loading surface, which is dependent on the mean normal stress, and on the normality of the deformation rate vector to these surfaces. Analytical forms of stressstrain relationships for these soil models are stated in incr~nental form, suitable for use in nmmerical analysis. Auth. 7~3
TRENEH WALL JACK: AN APPARatUS TO MEASURE THE EQUIVALENT ELASTIC MGDULUS OF SOIL La~rrence, G J L Transport and Road Research Lab supplementary report 347, 1977, 18P The apparatus described can be used to determine the load-deformation characteristics of insitu soil at the side of a trench. The testing procedure is given and results for equivalent modulus of elasticity in a re~oulded cohesive soil compared wlth those obtained from undrained triaxial tests. The values are in reasonable agreement, but results for the trench wall Jack are more consistent. The study relates to the structural design of buried, flexible pipelines. Avail : TRRL, 01d Wokinghem Road, Crowthcrne, Berks, UK
7~0~
DETERMINATION OF THE ROCK PROPERTIES THAT ARE MEASURED BY CYLINDRICAL PRESSURE CELL TESTS IN BOR~OLES Miller, R J; Duvall, W I; Wang, F D USBM 0FR 82-77, 0c% 1977, 47P Investigates the validity Of the ass~mptlon of complete pressure transfer through the s ~ l i p r e n e s l e e v e o f t h e CSM c e l l , a n d what e f f e c t r o c k properties have on the determination of deformation modulus by this cell. The feasibility of using inclusion geges in the sleeve to measure bmrehole dilatation directly was also studied. Theoretical analysis and practical tests led/cared that pressure transfer should be essentially complete, irdependent of the relative stiffness of the cylinder. A successfuX technique was developed for holding the gages in the
sleeve, am~ suggestion ma~e fcr for solvizg t~ ~roblems of too high strain o b s e r v e d in the gages. It was concluded that the use of inclu~ gages offered a faster, mc~e accurate tech~iq~ for obtalni~g defc~mation modulus in situ. Avail: NTIS, Springfield, Va, 22161, USA
(PB 266 829/AS) 784045 FABRICS AND THEIR EFFECT ON THE DEFOF~4ATION ~qqAVIOUR OF SAND Oda, M Saitama Univ, Del:~ o f Foundation EDgineerimg report (special issue), 1976, 59P Analyses 'derived properties' of sand such as shear stremgth, deformation modulus and permeability in terms of the following properties of the ir~llvidual particles: mineralogy, size, shape, spatial arrangement of particles and voids, ard also water content. Discusses furda men~al properties, fabric, effect of initial fabric on the triaxial compression test, and microscopic observation of deformation mechani in the triaxial compression test. Avail: Faculty of Emgineering, Saitama Univ, Urawa, Saitama, Japan
Time dependent behaviour 784046 CHEEP DEFORMATION OF CLAYS Wu, T H; E1 Refal, A N A A; AsU, J R J Geotech Engmg Div ASCE, V104, NGT1, Jan 1978, P61-76 Stress-strain-time behaviour was studied in several clay soils by drained triaxial tests a creep law was derived. The effects of incremental loadir~, anisctropic consolidation plane strain and simple shear were also investigated. The measured stress-strain-time relat: ship was used to compute displacements of an cavation near Cleveland and the results compared with field measurements. The final displacements were in reasonable agreement, but the computed creep rate is much smaller than t~ measured values. 784047 T~ME-DEPENDEN~ MULTILAMINATE MODEL OF ROCKS. A NUMERICAL STUDY OF DEFORMATION AND FAILURE OF ROCK MASSES Zienkiewicz, 0 C; Pande, G N Int J Num Anal Meth Geomech, V1, N3, July-Se]
1977, P219-247 A ne~ model for rocks and rock-Eke material with multiple planes of weakness is ~roposed. The behaviour of the assembly applies tensile and Mohr-Coulomb shear limits on each such pl~ with possible strain dependence of frictional properties. The visco-plastic algorithm which allows the incorporation of time effects is used to obtain static solutions. The model is illustrated by applications to stability of rc~ slopes and behavlour of tunnels. A ~neralizat~ of the model to include arbitrary threa-dimensional distribution of laminae in 'quasi-pla~ strain' is included. The effect of various flo~ rules adolf6ed for plastic straining is indicate Auth.