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Prevention of sample deterioration. Technical note
l I2A 893O38 Strain-rate influence on the interpretation of plate bearing tests. Technical note Georgiadis, M Geotech Test J VII, N4, Dec 1988. P293-295
893043 Behaviour of dry granular materials under repeated load hiaxial and triaxiai stress conditions. Technical note Shaw, P; Brown, S F Geotechnique V38. N4. Dec 1988, P627-634
The effect of loading rate on the load-settlement response of a bearing plate on clay was studied by performing model tests on a clay bed at 3 different loading rates. Results are interpreted using an exponential model which considers soil as a viscous material. Results show that ultimate capacity and stiffness characteristics of the clay are significantly affected by loading rate.
A pneumatically operated apparatus capable of applying two independent principal stresses under plane strain conditions has been used to examine the response of a 3mm single-size dry granular material. Comparison of results with those predicted using a model based on data from axisymmetric triaxial tests using a sophisticated servo-hydraulic apparatus has shown that this model can be extended to the general threedimensional stress state.
893039 Prevention of sample deterioration. Technical note Brown, P T; Chow, J C P Geotech Test J VII, N4, Dec 1988. P296-300
A simple sample compressor, which can restore in situ vertical stress in a sample and therefore prevent sample deterioration during storage, is described. Its effectiveness was tested by performing unconsolidated undrained triaxial tests on specimens which had been consolidated, unloaded and tested immediately, stored for I week, or not unloaded. Results show that unloading caused changes in undrained strength and modulus, and that the compressor eliminated potentially serious deterioration of the kaolin sample during I week storage. 893040 Uplift resistance of soils Suthcrland, H B Geotechnique V38. N4. Dec 1988. P493-516
28th Rankine Lecture. Using the Sizewell A site as an example, uplift resistance of soils is considered. Uplift resistance of cohesionless soils, cohesive soils and layered soils, modelling uplift resistance of clays, centrifuge tests and finite element models for uplift resistance, further model tests on cohesionless soils, offshore applications of embedded anchors and foundations for transmission line towers are discussed. 89304 ! Elasto-plastic version of the double sliding model in undrained simple shear tests de Josselin de Jong, G Geotechnique V38, N4, Dec 1988, P533-555
Use of the elasto-plastic double sliding, free rotating (DSFR) model for materials with internal friction to predict the stress history in undrained simple shear tests is presented. First, the dilatant version of DSFR model is redeveloped using only the laws of friction to give plastic constitutive equations, and then the elastic parts of the constitutive equations are derived. The response of the elasto-plastic DSFR sample in undrained simple shear is considered. The essential features of the stress history obtained from the analysis resemble those actually observed in tests. 893042 Analysis of the cone pressuremeter test in clay Houlsby, G T; Withers, N J Geotechnique V38, N4, Dec 1988, P575-587
The cone pressuremeter is a new in situ testing device combining an electric piezocone with the pressuremeter test. An analysis of the test in clay is presented. An analytical method to derive undrained shear strength and shear modulus from full displacement pressuremeter test data is outlined, and applied to 7 tests using the prototype cone pressuremeter. Derived strength and stiffness values are compared with other test data for the same site, showing good agreement.
893044 Influence of microfabric on behaviour of Tertiary fine-grained sedimentary rocks from central North Island, New Zealand Huppert. F lnt Assoc Engng Geol Bull N38, Oct 1988. P83-93
Behaviour of the soft sedimentary rocks was studied by considering the influence of microfabric. Structural elements, fabric arrangement and relation of microfabric to geotechnical behaviour are described. Results show 3 types of fabric, skeletal, matrix and turbostatic. Bonding, stability of structural elements and contact strength evolution during compaction and stress relief are discussed. 893045 Structural strength anisotropy of silty clays in connection with their shearing rate Kolodziejczyk, U lnt Assoc Engng Geoi Bull N38, Oct 1988. PI05-110 300 oriented samples were obtained in 3 directions perpendicular to each other, which marked the directions of the geological structure. The samples were sheared under triaxial compression at 3 rates of deformation,and spatial orientation of shear surfaces determined. Data were used to produce summary contour graphs. Application of "double spatial orientation" of the cylindrical samples enabled reference of each surface to in situ conditions so the geometrical relation of shear surfaces with stratification, direction of geological structures and orientation of natural colluvial surfaces could be established. 893046 Block punch index test van der Schrier, J S lnt Assoc Engng Geol Bull N38, Oct 1988, P121-126
The block punch index test has been developed to test small flat samples of rock. A variety of rock types was tested for uniaxial compressive strength, Brazilian tensile strength and block punch index value. Comparison of results showed reasonable agreement. The test is recommended as an index test not as a method for determining shear strength. 893047 Investigation into the influence of size on the mechanical properties of aggregates Turk, N; Dearman, W R Int Assoc Engng Geol Bull N38, Oct 1988, P143-149
Non-standard and standard size aggregates were tested under BS 812-1975 to assess the effect of aggregate size on aggregate mechanical properties. Two dolerites, a granite and 2 limestones were tested. Results show that aggregate impact value (AIV), aggregate crushing value (ACV) and 10% fines load values were aggregate size dependent. Relationships between the results are discussed.
!~ 1989 Pergamon Press plc. Reproduction not permitted
893043 Behaviour of dry granular materials under repeated load hiaxial and triaxiai stress conditions. Technical note Shaw, P; Brown, S F Geotechnique V38. N4. Dec 1988, P627-634
The effect of loading rate on the load-settlement response of a bearing plate on clay was studied by performing model tests on a clay bed at 3 different loading rates. Results are interpreted using an exponential model which considers soil as a viscous material. Results show that ultimate capacity and stiffness characteristics of the clay are significantly affected by loading rate.
A pneumatically operated apparatus capable of applying two independent principal stresses under plane strain conditions has been used to examine the response of a 3mm single-size dry granular material. Comparison of results with those predicted using a model based on data from axisymmetric triaxial tests using a sophisticated servo-hydraulic apparatus has shown that this model can be extended to the general threedimensional stress state.
893039 Prevention of sample deterioration. Technical note Brown, P T; Chow, J C P Geotech Test J VII, N4, Dec 1988. P296-300
A simple sample compressor, which can restore in situ vertical stress in a sample and therefore prevent sample deterioration during storage, is described. Its effectiveness was tested by performing unconsolidated undrained triaxial tests on specimens which had been consolidated, unloaded and tested immediately, stored for I week, or not unloaded. Results show that unloading caused changes in undrained strength and modulus, and that the compressor eliminated potentially serious deterioration of the kaolin sample during I week storage. 893040 Uplift resistance of soils Suthcrland, H B Geotechnique V38. N4. Dec 1988. P493-516
28th Rankine Lecture. Using the Sizewell A site as an example, uplift resistance of soils is considered. Uplift resistance of cohesionless soils, cohesive soils and layered soils, modelling uplift resistance of clays, centrifuge tests and finite element models for uplift resistance, further model tests on cohesionless soils, offshore applications of embedded anchors and foundations for transmission line towers are discussed. 89304 ! Elasto-plastic version of the double sliding model in undrained simple shear tests de Josselin de Jong, G Geotechnique V38, N4, Dec 1988, P533-555
Use of the elasto-plastic double sliding, free rotating (DSFR) model for materials with internal friction to predict the stress history in undrained simple shear tests is presented. First, the dilatant version of DSFR model is redeveloped using only the laws of friction to give plastic constitutive equations, and then the elastic parts of the constitutive equations are derived. The response of the elasto-plastic DSFR sample in undrained simple shear is considered. The essential features of the stress history obtained from the analysis resemble those actually observed in tests. 893042 Analysis of the cone pressuremeter test in clay Houlsby, G T; Withers, N J Geotechnique V38, N4, Dec 1988, P575-587
The cone pressuremeter is a new in situ testing device combining an electric piezocone with the pressuremeter test. An analysis of the test in clay is presented. An analytical method to derive undrained shear strength and shear modulus from full displacement pressuremeter test data is outlined, and applied to 7 tests using the prototype cone pressuremeter. Derived strength and stiffness values are compared with other test data for the same site, showing good agreement.
893044 Influence of microfabric on behaviour of Tertiary fine-grained sedimentary rocks from central North Island, New Zealand Huppert. F lnt Assoc Engng Geol Bull N38, Oct 1988. P83-93
Behaviour of the soft sedimentary rocks was studied by considering the influence of microfabric. Structural elements, fabric arrangement and relation of microfabric to geotechnical behaviour are described. Results show 3 types of fabric, skeletal, matrix and turbostatic. Bonding, stability of structural elements and contact strength evolution during compaction and stress relief are discussed. 893045 Structural strength anisotropy of silty clays in connection with their shearing rate Kolodziejczyk, U lnt Assoc Engng Geoi Bull N38, Oct 1988. PI05-110 300 oriented samples were obtained in 3 directions perpendicular to each other, which marked the directions of the geological structure. The samples were sheared under triaxial compression at 3 rates of deformation,and spatial orientation of shear surfaces determined. Data were used to produce summary contour graphs. Application of "double spatial orientation" of the cylindrical samples enabled reference of each surface to in situ conditions so the geometrical relation of shear surfaces with stratification, direction of geological structures and orientation of natural colluvial surfaces could be established. 893046 Block punch index test van der Schrier, J S lnt Assoc Engng Geol Bull N38, Oct 1988, P121-126
The block punch index test has been developed to test small flat samples of rock. A variety of rock types was tested for uniaxial compressive strength, Brazilian tensile strength and block punch index value. Comparison of results showed reasonable agreement. The test is recommended as an index test not as a method for determining shear strength. 893047 Investigation into the influence of size on the mechanical properties of aggregates Turk, N; Dearman, W R Int Assoc Engng Geol Bull N38, Oct 1988, P143-149
Non-standard and standard size aggregates were tested under BS 812-1975 to assess the effect of aggregate size on aggregate mechanical properties. Two dolerites, a granite and 2 limestones were tested. Results show that aggregate impact value (AIV), aggregate crushing value (ACV) and 10% fines load values were aggregate size dependent. Relationships between the results are discussed.
!~ 1989 Pergamon Press plc. Reproduction not permitted