Laws of volumetric deformation and particle breaking of calcareous sand under cyclic loading

Abstract

In order to study the change law of volume deformation and particle breakage of calcareous sand under cyclic loading, this paper carries out both conventional triaxial consolidated drained shear tests (the conventional tests) and triaxial cyclic loading tests on calcareous sand. The test results under these two stress paths were compared and showed that, compared with the stress path of the conventional tests, the stress path of cyclic loading aggravates the softening features of the calcareous sand. In each cycle, there is a hysteresis loop in the stress-strain curve, whose area is proportional to the deviator stress level at the initial stage of unloading. The stress path of cyclic loading suppresses the dilation trend of the sample under low cell pressure; the contraction amount is positively correlated with the deviator stress in the unloading phase. The two stress paths bring similar particle breaking law. Under the same cell pressure, the shear moduli of calcareous sand particles decrease with the growing cycle number. The manuscript clarified the law of deformation and particle breakage of calcareous sand under cyclic loading, which provided a theoretical basis for practical engineering.