Abstract: Cohesive soil containing calcareous nodules has unique material composition and structure, and there has been relatively little research on its soil dynamics. In this paper, a series of dynamic triaxial tests of cohesive soil containing calcareous nodules with different particle sizes and mass fractions of nodules were carried out to study the influence of the presence of nodules on the dynamic elastic modulus of cohesive soil containing calcareous nodules. The test results show that with the increase of the number of cycles, the dynamic elastic modulus of the soil decreases rapidly at first, and then the reduction amplitude gradually decreases with the increase of dynamic strain. With the increase of particle size or mass fraction of nodules, the dynamic elastic modulus of the soil increases, and the ability of the soil to resist deformation under dynamic loads becomes stronger. Particle flow code (PFC2D) was used to numerically simulate the dynamic triaxial test of cohesive soil containing calcareous nodules. The simulation results indicate that under cyclic loading, the nodules significantly hinder the displacement of fine particles around them, and significant stress concentration is generated around the nodules, forming a "skeleton" of the soil. From a microscopic perspective, the influence and role of the presence of nodules on the dynamic elastic modulus of the soil are explained. The research results have laid the foundation for the dynamic research of cohesive soil containing calcareous nodules, and have important reference value for the dynamic research of other similar structured soils.
Keywords: cohesive soil containing calcareous nodules; cyclic loading; dynamic elastic modulus; hysteresis curve; particle flow code
合肥工业大学学报自科版