DEM analysis of evolution law of bond degradation for structured soils
LI Tao1, JIANG Ming-jing1,2,3,4, SUN Ruo-han1
1. Department of Civil Engineering, Tianjin University, Tianjin 300072, China; 2. Key Laboratory of Earthquake Engineering Simulation and Seismic Resilience, China Earthquake Administration (EESSR), Tianjin University, Tianjin 300072, China; 3. State Key Laboratory of Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, China; 4. Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China
Abstract：The evolution of bond degradation is essential for analyzing the macro-and micro-scopic behaviors and establishing constitutive models for structured soils with cementation bond which is a kind of bonded granular material. The discrete element method is employed to analyze the evolution of bond degradation on account of the disadvantage of laboratory tests in bond breakage quantitative analysis. First, the discrete numerical sample is generated by installing a relatively completed bond contact model incorporating the interparticle rolling and twisting resistances and the influences of bond size on the contact stiffness and strength. The DEM simulation reproduces the key mechanical behaviors of one-dimensional compression, isotropic and anisotropic compressions, conventional triaxial and true triaxial tests on the DEM sample. The results show that the evolution of the degradation variable B0 is stress-path-dependent, while a new degradation variable Bσ is roughly stress-path-independent. An exponential function is recommended for Bσ to describe the degradation of soil structure.
李涛, 蒋明镜, 孙若晗. 多种应力路径下结构性土胶结破损演化规律离散元分析[J]. 岩土工程学报, 2020, 42(6): 1159-1166.
LI Tao, JIANG Ming-jing, SUN Ruo-han. DEM analysis of evolution law of bond degradation for structured soils. Chinese J. Geot. Eng., 2020, 42(6): 1159-1166.
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