基于DDA的膨胀土边坡破坏过程模拟

摘要

采用非连续变形分析方法DDA模拟膨胀土边坡的破坏过程.根据膨胀土边坡浅层破坏特征和Mohr-Coulomb准则,设置了3组潜在剪切破坏面,它们互相切割形成块体系统.基于试验数据,假定了土体变形参数和抗剪强度参数与含水量的关系.土体的吸湿膨胀作用按初应变考虑.计算结果表明,膨胀土边坡在吸湿膨胀和强度降低后发生浅层顺坡向滑动破坏,与工程实际破坏现象吻合.建立的计算模型,为进一步研究膨胀土边坡的稳定性和加固措施奠定了基础.%Discontinuous deformation analysis ( DDA) is used to simulate the failure process of expansive soil slopes. According to the characteristic of shallow landslide of expansive soil slopes and the Mohr-Coulomb criterion, three groups of potential failure planes, which cut each other and generate block system, are assumed. On the basis of experimental data, relationships between the material parameters and the water content of expansive soil are assumed. The strain of hygroscopic expansion is treated as initial strain. The computed result shows that shallow landslide of an expansive soil slope happens after swelling and shear strength reduction due to the moisture absorption. This result is in accordance with the failure of expansive soil slopes in practice. The calculation model established in this paper provides a sound base for further studies of stability and reinforcement measures of expansive soil slopes.