Standard Test Method for Consolidated Undrained Cyclic Direct Simple Shear Test under Constant Volume with Load Control or Displacement Control

Importancia y uso:

5.1 Cyclic direct simple shear strength test results are used most often for evaluating the ability of a soil to resist shear stresses induced in a soil mass during earthquake loading, offshore storm loading, etc.

5.2 In this test, the cyclic strength is measured under constant volume conditions that are equivalent to undrained conditions; hence, the test is applicable to field conditions in which the soils have consolidated under one set of stresses, and then are subjected to changes in stress/strain without time for further drainage to take place.

5.3 The cyclic strength is a function of many factors including density, confining pressure, stress history, grain structure, specimen preparation procedure, frequency, and characteristics of the cyclic loading applied. Therefore, test factors shall be considered during evaluation of test results.

5.4 The state of stress within the direct simple shear specimen is not sufficiently defined nor uniform enough to allow rigorous interpretation of the results. Expressing the data in terms of the shear stress and vertical effective stress on the horizontal plane is useful for engineering purposes. Some effective stress parameters that could be derived from a cyclic direct simple shear test shall not be confused with corresponding parameters derived from other shear tests having better defined states of stress (that is, cyclic triaxial tests).

5.5 The values of settlement in saturated soil after cyclic loading can be assessed from the test results by allowing volume change at the end of the shearing to achieve same vertical effective stresses as at end of primary consolidation.

5.6 The data from the consolidation portion of this test are comparable to results obtained using Test Method D2435/D2435M provided that the more rigorous consolidation procedure of Test Method D2435/D2435M is followed.

Subcomité:

D18.09

Volúmen:

04.09

Número ICS:

13.080.20 (Physical properties of soils)

Palabras clave:

clays; cohesive soils; cohesionless soils; compacted samples; consolidated undrained test; consolidation test; constant volume test; cyclic direct simple shear; cyclic strength; cyclic stress ratio; double amplitude shear strain; intact samples; liquefaction; pluviated samples; reconstituted samples; soils; stress-strain curve; undrained cyclic shear test;