【摘要】 通过对黏性试样进行室内三轴固结排水试验,研究黏性土体的工程力学性质,得到了试样土体的应力-应变关系曲线以及强度指标,基于颗粒流离散元法的原理,利用PFC3D软件建立三轴试样模型,并设定颗粒间的接触为接触黏结模型,通过颗粒流数值试验对细观参数进行标定,从细观角度对黏性土的工程力学特性做了一定的研究。对比了不同围压下数值试验与室内试验的应力-应变关系曲线,得到了较好的模拟效果。分析细观参数的变化对黏性土的应力-应变关系曲线的影响,得出边界条件、孔隙率、黏结强度、摩擦系数、接触刚度等细观参数的取值对黏性土的宏观力学性质有着显著的影响并对影响规律做了探讨,为今后的三轴试验颗粒流数值模拟提供了有价值的参考。更多还原

【Abstract】 In order to study the engineering mechanics properties of cohesive soil,the stress-strain curves and the strength indexes of the sample soil is acquired through conducting the laboratory consolidated drained triaxial test with the cohesive soil. The numerical model is built by using PFC3 D code based on the principle of particle flow discrete element. The contact between balls is set as contact-bond model. After conducting the particle flow numerical test and calibrating the mesoscopic parameters,some research on the engineering mechanics properties of cohesive soil are conducked from the perspective of mesoscopic. The stress-strain curves under different confining pressures of laboratory test and numerical test are compared,the simulation effect is remarkable. The conclusion is that the values of some mesoscopic parameters have a significant influence to the macroscopic mechanical properties of cohesive soil by analyzing the stress-strain curves. The mesoscopic parameters include boundary conditions,porosity,bonding strength,friction coefficient,contact stiffness and so on. The law of the influence has been discussed and it provides a valuable reference to the particles flow numerical simulation of triaxial test for the future.更多还原