Distinct Element Approach to the Bearing Capacity of Granular Material

• Main Authors: Cheng-Chang Cheng, 鄭承昌
• Other Authors: Meng-Chia Weng
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/28718438257458080599

碩士 === 國立高雄大學 === 土木與環境工程學系碩士班 === 97 === Traditionally, the bearing capacity of shallow foundation and the active or the passive earth pressure of retaining wall are obtained from limit equilibrium method based on the mechanics of continuum. However, the geo-material is mainly composed of discrete particles, and it often exhibits flow behavior, which is different from the continuous solid. Therefore, this research aims to realize the mechanical behavior of granular material using the software PFC2D based on the distinct method (DEM). Firstly, the micro parameters of granular material were verified by the direct shear test. Then, the influences of the particle size, the packing, the friction coefficient of particle and the stiffness on the bearing capacity and the earth pressure were explored. The simulation results show that: (1) For particles with simple packing and random packing, the bearing capacity of foundation is lower than that with dense packing; (2) an increasing friction coefficient increase the bearing capacity; (3) the larger size and the higher stiffness will lead to the higher strength. Among the factors, the influence of stiffness is more apparent than that of other factors. For the results of earth pressure, aforementioned tendencies are also observed. Furthermore, triaxial tests of granular material are simulated. The results shows that the failure envelope is nonlinear and the plastic deformation reveals non-associated flow.