复合加载模式下地基失效机制研究

在土体极限平衡定理的基础上，利用有限元数值分析软件ABAQUS对复合加载模式下地基失效机制进行了详细地研究。结果表明，竖向荷载V控制着地基破坏滑裂面的深浅程度，水平荷载H和力矩荷载M造成了地基破坏模式的非对称性；文中提出的前倾勺形破坏模式和后仰勺形破坏模式，合理地解释了H-M荷载空间中破坏包络面的非对称性，并给出了H-M荷载空间中不同的地基失效模式与荷载分量间的关系和地基土体中出现极限力矩荷载时的经验判断公式。

Study of failure patterns of foundation under combined loading

Based on the limit equilibrium method, the failure patterns of undrained saturated foundation under combined loading are investigated by virtue of the finite element software ABAQUS in detail. The conclusion shows that the vertical loading V can control the extent of depth of the sliding surface, the horizontal loading H and the moment loading M make the failure envelope of foundation asymmetry; the forward-tilted scoop failure mode and the backward-tilted scoop failure mode, which are given in this paper, can interpret properly the asymmetry of failure envelope in H-M loading space. Finally, the relationship between the different failure patterns and the loading compound modes in H-M loading space is given; moreover, the discrimination equation of appearance of maximum moment Mmax is given.