Earth Pressures at Rest Related to Stress History

1965 ◽  
Vol 2 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Elmer W Brooker ◽  
Herbert O Ireland
Keyword(s):  
Axial Stress ◽  
Earth Pressure ◽  
Lateral Strain ◽  
Cohesive Soils ◽  
Stress History ◽  
Chicago Clay ◽  
Liquidity Index ◽  
Shearing Resistance ◽  
History Of ◽  
London Clay

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.

Effects of Stress Path and Stress History on the Stiffness of Reconstituted London Clay

1986 ◽  
Vol 2 (1) ◽  
pp. 139-144 ◽  
Author(s):  
J. H. Atkinson ◽  
J. S. Evans ◽  
D. Richardson
Keyword(s):  
Stress Path ◽  
Triaxial Tests ◽  
Soil Parameters ◽  
Stress History ◽  
Strain Behaviour ◽  
Reconstituted Soil ◽  
Path Dependent ◽  
London Clay ◽  
Soil Behaviour

AbstractSoil behaviour is stress history dependent and stress path dependent and soil parameters, particularly those for stress-strain behaviour, measured in conventional triaxial tests may not represent the behaviour of soil in many civil engineering works.To obtain more realistic parameters it may be necessary to conduct laboratory tests which more closely represent in situ conditions before and during construction.The paper describes equipment developed at The City University to carry out stress path tests simply and economically. A series of CU triaxial tests and stress path tests on reconstituted soil illustrate the dependence of measured soil parameters on stress history and stress path.

Effect of stress history of saturated clay on engineering behaviour of an energy pile

2020 ◽  
pp. 1-10
Author(s):  
Di Wu ◽  
Han-Long Liu ◽  
Gang-Qiang Kong ◽  
Hossam Abuel-Naga
Keyword(s):  
Stress History ◽  
Energy Pile ◽  
Saturated Clay ◽  
History Of

Evolutionary relationships of the Sparidae (Teleostei: Percoidei): integrating fossil and Recent data

2002 ◽  
Vol 93 (4) ◽  
pp. 333-353 ◽  
Author(s):  
Julia J. Day
Keyword(s):  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
Successive Approximations ◽  
Feeding Strategies ◽  
New Genera ◽  
Minimum Age ◽  
Character Weighting ◽  
History Of ◽  
London Clay ◽  
Fossil Data

ABSTRACTThe Eocene sparid fauna (Teleostei: Percoidei) from Monte Bolca, Italy and from the London Clay, U.K. is revised based on re-examination of the type material and phylogenetic analyses of primarily osteological data. Two phylogenetic analyses, one of the Eocene taxa and a combined analysis of fossil and extant taxa, were performed. The addition of fossils to the extant data greatly increased numbers of most parsimonious trees, destabilising and obscuring basal relationships within the Sparidae. Combination of the data from fossil and extant data also affected relationships among the fossil taxa, changing some from those recovered using fossil data alone and destabilising others. Successive approximations character weighting supported the inclusion of the Eocene taxa within a monophyletic Sparidae. The genus Sparnodus, as previously conceived, is paraphyletic and is partitioned to remove the paraphyly. Five monotypic genera are recognised, including three new genera, Abromasta, Ellaserrata and Pseudosparnodus. Inclusion of the fossils in the phylogenetic analysis implies a minimum age of origin for the Sparidae of 55 Ma with most Recent sparid fauna in place no later than the Miocene, and provides further evidence that the diversification of feeding strategies occurred early on in the evolutionary history of the group.

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