DEM analyses of the whole failure process of shallow foundation in plate load test on dense sand

International Symposium on Geohazards and Geomechanics 2015

地球科学;生态环境科学

Li, L.^1,2,3 ; Jiang, M.J.^1,2,3 ; Li, T.^1,2,3 ; Chen, S.L.^4

State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, Shanghai

200092, China^1

Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai

200092, China^2

Department of Geotechnical Engineering, Tongji University, Shanghai

200092, China^3

Transportation and Municipal Mngineering Institute, Hydrochina Huadong Engineering Corporation, Hangzhou

310014, China^4

关键词: Deformation pattern;    Engineering practices;    Instability mechanisms;    Microscopic features;    Particle velocities;    Shallow foundations;    Strain-softening materials;    Vertical loadings;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/26/1/012039/pdf
DOI  :  10.1088/1755-1315/26/1/012039

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

Shallow foundations are widely used in civil engineering practice, but the instability mechanism is still unclear yet. Previously, the Finite Element Method (FEM) was commonly used to analyze the failure process of shallow foundations, but it meets difficulty in properly simulating the whole failure process of shallow foundation on the strain-softening material. Hence, the Discrete Element Method (DEM) is employed in this paper to study the instability mechanism of the shallow foundation via numerical plate load test with focus on the microscopic features evolution during vertical loading. In the simulation, an amplified gravity was applied to a dense granular ground to reproduce a gravity stress state at a large scale. Then, a plate was put on the granular ground to simulate the plate load test. Deformation pattern, particle velocity and distribution of void ratio in the ground were examined to illustrate the microscopic features in the whole failure process of the granular ground. The results show that: 1) There are a marked peak value and a settlement softening branch in the stress-settlement relationship. 2) The grids close to the edge of the plate are peculiarly extended and twisted. 3) Four particle motion patterns were observed in the velocity fields and the percentage of each motion pattern changes during loading. 4) The void ratio field varies during loading, and the distinguishing interface tends to be similar to Terzaghi's shear failure surface.