采用隐式锚索单元模拟地下洞室预应力锚索，探讨了索体对岩体单元的等效附加刚度贡献。针对预应力锚索的受力过程，分别分析了预拉力和围岩变形作用下锚索锚固段的受力机制。基于两种作用下锚固段内力的叠加，提出了一种考虑锚固界面剪切滑移的预应力锚索受力分析方法。结合三维非线性有限元，给出了预应力锚索受力的一般求解步骤，然后将此锚索算法应用于乌东德水电站左岸地下厂房洞室群分期开挖。结果表明，锚索支护能够有效加固岩体，限制破坏区的发展；锚固段轴力和剪应力均在始端达到最大，沿深度方向逐渐衰减。计算得到的锚固力变化过程与实测值基本吻合，验证了该算法的合理性。

The implicit anchor cable element is adopted to simulate prestressed anchor cable in underground caverns. The equivalent additional stiffness contribution of the anchor cable attached to the rock element is discussed. Aimed at the loading process of the prestressed anchor cable, the force mechanisms of anchorage section under pre-tension and rock deformation loads are analyzed respectively. Based on internal force superposition of the anchorage section under the two loads above, a force analysis method for the prestressed anchor cable considering shear slip on the anchoring interface is proposed. Combined with the 3D nonlinear FEM, the general solving steps of force for the prestressed anchor cable are given. Then, the algorithm for the anchor cable is applied to the multistage excavations of the left bank underground caverns of Wudongde hydropower station. The results show that the anchor cable support can reinforce the rock effectively and restrict the development of damage zone. The axial force and shear stress of the anchorage section both reach the maximum at the anchor end, and decay along the depth direction. The calculated anchoring forces correspond well with the measured values, so as to verify the rationality of the algorithm.