摘要:

A graphical interpolation method which had previously been used for predicting the behaviour of sand in triaxial test conditions has been modified to become applicable to a remoulded saturated clay.The method consists in covering a given region of the principal stress plane by the results of a number of drained compression tests whose stress paths are related to a common consolidation line and are sufficiently close to each other so as to enable intermediate values of different parameters to be found by simple interpolation.The method was applied to a remoulded saturated clay both in normally consolidated and overconsolidated state, and an attempt was made to predict by interpolation the behaviour of the clay in undrained shear and K0-consolidation test respectively.By comparing the predicted behaviour of the clay with that observed in actual tests, a fair agreement was found for undrained tests, whereas for the K0-consolidation test the agreement was poor.It is suggested that the predicting of the behaviour of the clay in a given type of test on the basis of a general picture obtained from a series of tests of a different type is possible provided that in both types of tests the type of consolidation, the sign of the isotropic and deviatoric components of the strain tensor, and the rate of strain are respectively the same.

ISSN:0008-3674    

DOI:10.1139/t65-007

出版商:NRC Research Press    

年代:1965

数据来源: NRC

ISSN:0008-3674    

DOI:10.1139/t65-008

出版商:NRC Research Press    

年代:1965

数据来源: NRC

ISSN:0008-3674    

DOI:10.1139/t65-009

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

The rate at which soil specimens are compressed in the standard consolidation test is farther from reality than the rate of strain in any other test. For a short period after the application of a load increment the rate of compression may be several million times faster than that experienced in the field. This paper describes a series of tests carried out at constant rates of compression varying from 0.16 to 8 per cent per hour in which pore pressures were measured. The effective stress-compression curves are compared with an average curve obtained by incremental loading. Based on these results, it is concluded that the compressibility of this soil is dependent on the average rate of compression and that the soil structure has a substantial time-dependent resistance to compression. This time-dependent resistance may be expected to have a significant influence on computed permeability coefficients and field rates of consolidation.

ISSN:0008-3674    

DOI:10.1139/t65-010

出版商:NRC Research Press    

年代:1965

数据来源: NRC

ISSN:0008-3674    

DOI:10.1139/t65-011

出版商:NRC Research Press    

年代:1965

数据来源: NRC

ISSN:0008-3674    

DOI:10.1139/t65-012

出版商:NRC Research Press    

年代:1965

数据来源: NRC

ISSN:0008-3674    

DOI:10.1139/t65-013

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Dense, heavily preconsolidated glacial till is a relatively incompressible soil that occurs throughout most of Canada. When loaded, it undergoes very small settlement, most of which is elastic. For the average structure, these elastic compressions are too small to be of concern and are usually ignored. However, for some structures they can be critical and their magnitude must be estimated prior to construction. To make the necessary analyses requires knowledge of the elastic properties of thein situglacial till.This paper presents the results of field and laboratory tests that were made on a dense glacial till deposit to determine its modulus of elasticity, in connection with the design and construction of a 100 ft. high combined earth and concrete dam. In the field,in situloading tests were made against the walls of a 50 ft. deep test shaft. The modulus of elasticity was computed, using elastic equations applicable to the case of a rigid circular plate pressed against a semi-infinite elastic solid. Moreover, during construction of the project, measurements were made of the elastic rebounds and settlements that occurred under known conditions of unloading and loading. Steinbrenner’s approximate solution for computing settlement due to loads acting on the surface of an elastic layer was then used to compute the apparent modulus of elasticity. In the laboratory, unconfined compression tests and repetitive triaxial tests were made on undisturbed samples. The modulus of elasticity was estimated from the stress-strain relationships obtained.The data presented in the paper indicate that the apparent,in situmodulus of elasticity of the glacial till deposit is very high, being in the order of 150,000 lb./sq. in. Reasonable agreement exists between modulus of elasticity values computed from thein situplate bearing tests and those computed from observed rebounds and settlements. However, modulus of elasticity values computed from unconfined compression and repetitive triaxial tests in the laboratory are apparently too small, being only a fraction of those values obtained by the field procedures. Sample disturbance is thought to be a major factor affecting laboratory test results.Grain size characteristics, density, natural water content, and strength properties of the glacial till deposit are presented in the paper. These data provide a comprehensive description of the material and permit comparison with glacial till deposits encountered at other areas.

ISSN:0008-3674    

DOI:10.1139/t65-014

出版商:NRC Research Press    

年代:1965

数据来源: NRC

ISSN:0008-3674    

DOI:10.1139/t65-015

出版商:NRC Research Press    

年代:1965

数据来源: NRC

ISSN:0008-3674    

DOI:10.1139/t65-016

出版商:NRC Research Press    

年代:1965

数据来源: NRC