A series of test simulating repeated loading due to the change of groundwater level and traffic load on the peat deposit is performed with stress condition of anisotropic consolidation and swelling. After anisotropic consolidation under cyclic loading for undisturbed peat, the effect of cyclic consolidation history on the shear characteristics is examined under undrained triaxial and unconfined compression tests.
The ground that consists of fibrous organic matter is well known in comparison with the cohesive soil as the most typical example of soft ground. Therefore, it seems that shear behavior is shown to be effect greatly by repeated loading due to the change of groundwater level and traffic load on the peat deposit. And the peat sample will be subjected to stress release and mechanical disturbance during the course from sampling to laboratory testing under cyclic loading. Kamiya (1990) performed a series of consolidation test for studying the effect of loading conditions on repeated cyclic loading of peat using consolidation test apparatus, and proposed at examining settlement behavior due to repeated cyclic loading of peat. In the study, a series of test simulating repeated loading due to the change of groundwater level and traffic load on the peat deposit is performed with stress condition of anisotropic consolidation and swelling. After anisotropic consolidation under cyclic loading for undisturbed peat, the effect of cyclic consolidation history on the shear characteristics is examined under undrained triaxial and unconfined compression tests.
The samples used in the experiments are undisturbed peat retrieved from a site in the vicinity of Akita City, index properties of which are given in Table 1. The sample used in this study is undisturbed peat obtained by forcing sampling tubes of 70mm in diameter and 300mm inlength with man power into peat layer
