摘要:

The influence of stress history on the coefficient of earth pressure at rest of remoulded cohesive soils was studied experimentally. A one-dimensional compression test cell and auxiliary controls which enabled the measurement of radial stresses under a condition of zero lateral strain was developed for this purpose. Radial pressures were measured throughout all stages of consolidation up to a maximum axial stress of 2,200 psi and subsequent rebound to zero stresses.Five cohesive soils, the properties of which are well documented, were selected for this study. These soils were: Chicago Clay, Goose Lake Flour, Weald Clay, London Clay, and Bearpaw Shale. 'The selected soils range in plasticity from low to high and cover a range of drained angles of shearing resistance from 15.5 degrees to 27.5 degrees. For testing purposes all soils were remoulded at a liquidity index of 0.5.For a pre-consolidation load of 2,200 psi and various values of the over-consolidation ratio, it was found that the coefficient of earth pressure at rest is related to both the drained angle of shearing resistance and the plasticity index. The coefficient of earth pressure at rest during rebound was found to be a function of the stress history of the soil as defined by the pre-consolidation load and over-consolidation ratio.

ISSN:0008-3674    

DOI:10.1139/t65-001

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

The influence of texture on shrinkage was studied for samples prepared in the laboratory to have varying proportions of Leda clay and glass beads. Total shrinkage and moisture content at the shrinkage limit increased linearly with the percentage of clay as long as the clay formed a continuous matrix. At lower clay concentrations shrinkage decreased rapidly. Total shrinkage per unit weight of clay in the mixtures increased with decreasing clay content, because the clay in parallel orientation around glass beads had a higher moisture content than the remainder of the clay.

ISSN:0008-3674    

DOI:10.1139/t65-002

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

A number of case histories are presented in which damage to structures supported on shallow foundations in the Chicago area have occurred due to desiccation. Particular emphasis is placed on the soil properties at each site, proximity of trees and root systems, surface run-off characteristics, and climatic factors. Also included is a discussion of the process by which trees cause desiccation and of some general rules to minimize this problem, as well as a discussion of means of arresting settlements of existing structures affected by desiccation.

ISSN:0008-3674    

DOI:10.1139/t65-003

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

The influence of the first invariant of the effective stress tensor upon the deviatoric response of a cohesive soil is investigated. Triaxial compression tests with effective octahedral normal stress control show the deviatoric stress-strain response to be definitely affected by the value of the effective octahedral stress,. The values ofrange from 7.5 psi to 30.0 psi. For a constant value of strain, the deviatoric stress increases with an increase in. The ultimate shear strength can be approximated as a linear function of. Hyperbolic representation of the stress-strain response provides a convenient method for obtaining a measure of the ultimate shear strength using the response of stress states other than failure. The deviatoric stress-strain response as a function of the effective octahedral stress,, can be expressed in the normalized formwhere ε is the strain,is a measure of the shear strength expressed in terms of, andAas well asBare numerical coefficients

ISSN:0008-3674    

DOI:10.1139/t65-004

出版商:NRC Research Press    

年代:1965

数据来源: NRC

ISSN:0008-3674    

DOI:10.1139/t65-005

出版商:NRC Research Press    

年代:1965

数据来源: NRC

ISSN:0008-3674    

DOI:10.1139/t65-006

出版商:NRC Research Press    

年代:1965

数据来源: NRC