中文摘要：

分析了软弱夹层的存在对三维边坡稳定性和破坏模式的影响．对一个经典的三维边坡算例进行了数值计算，并将结果与极限平衡法进行了对比，以验证强度折减弹塑性有限元法的可靠性．然后对一个含软弱夹层三维边坡进行了分析，计算结果表明：强度折减弹塑性有限元法计算的椭球破坏面在纵向长度上比极限平衡法要大；与三维均质边坡相比，三维软夹层边坡安全系数要低很多，破坏面的范围更大，塑性应变区的集中现象更加明显，破坏模式有着明显的不同．

英文摘要：

This paper analyzes the impact of the weak interlayer on the 3D slope stability and failure mode. Example of a classic 3D slope is calculated and the results were compared with the limit equilibrium method to verify the reliability of strength reduction elastoplastic finite element method. And then an example of a 3D slope with weak interlayer is analyzed, the results show that： the ellipsoid failure surface in the longitudinal length calculated by strength reduction elastoplastic finite element method is larger than the limit equilibrium method; compared with the 3D homogeneous slope, the factor safety of 3D slope with weak interlayer is much lower, the scope of failure surface is much larger, the phenomenon of the concentration of plastic strain zone is more obvious, and the failure mode has many significant differences.