为进行渗流作用下的边坡稳定性分析,需考虑渗流场与应力场之间的相互耦合作用。ABAQUS有限元程序具有良好的渗流和变形耦合分析功能,能将渗流场和应力场直接进行耦合,故采用ABAQUS有限元程序结合强度折减技术进行稳定渗流作用下边坡稳定分析,得到边坡整体稳定安全系数,且利用该程序强大的后处理功能,可揭示坡体内渗流浸润面和最危险滑动面的形状和位置,为验证该方法的可靠性,与基于传统极限平衡理论的瑞典条分法和简化的Bishop法进行对比分析。实例计算结果表明,基于ABAQUS的有限元强度折减法克服传统极限平衡法的缺点,计算结果更为合理可靠,是进行渗流作用下边坡稳定这一复杂问题分析的有效方法,可为工程实践提供参考依据。同时,就土体渗透性强弱对渗流浸润面位置及边坡稳定性的影响进行大量的分析和比较,并通过计算表明有限元模型边界的选取对渗流浸润面位置及边坡稳定性都会产生影响,因此有限元建模应合理地选取计算边界。
In order to analyze the slope stability under seepage, the coupling effect of seepage field and stress field needs to be considered. The ABAQUS finite element program has good coupling analysis function of deformation and seepage, and the seepage field can be coupled with the stress field directly. So the ABAQUS finite element program which is combined with strength reduction technique was used to analyze the slope stability under seepage, and the safety factors of slope stability were obtained. The shapes and positions of seepage of saturated surfaces and the most dangerous slip surfaces could be revealed by using the strong post processing functions of ABAQUS program. To verify the accuracy of this method, it was compared with the Sweden slice method and simplified Bishop method that both were based on the traditional limit equilibrium theory. The engineering example showed that the strength reduction FEM based on the software ABAQUS could overcome the disadvantages of the traditional limit equilibrium methods, and its results were more reasonable and reliable. This method was effective to analyze the complicated problem of slope stability under seepage, and the conclusions could provide references to the engineering practice. Meanwhile, the influences of the permeability of soil on the positions of seepage of saturated surfaces and slope stability were made a mass of analysis and comparison, and the calculation indicated that choosing finite element model borders influenced the positions of seepage of saturated surfaces and slope stability. So finite element modeling should choose calculation borders reasonably.