大岗山水电站右岸边坡位于大渡河断裂和磨西断裂所切割的断块上，地震发生频繁且烈度高，岩体卸荷强烈，构造稳定性差，裂隙发育集中。已有研究成果显示出边坡开挖过程中锚索支护的重要性，也有较多学者对抗剪洞支护的设计进行了较全面的研究。在已有的锚索支护基础上，基于卸荷理论对设计抗剪洞的再次支护效果和和采用拟静力法模拟的抗震效果进行评估，通过不同高程的关键点的位移响应，较系统地论证抗剪洞设置的必要性。通过研究应力的变化发现锚索支护段和抗剪洞支护段之间形成较为明显的拉裂区域。对工程后期监测提出建议。

The Dagangshan hydropower station’s right bank slope is located on the fault block cut by Dadu River and Moxi fractures; over there, the high intensity earthquake happened frequently; the rock mass is strongly unloaded, with poor stability structure and intensively cracks. The importance of cable support in slope excavation process has been shown in existing researches; while the design of shear hole support has been studied comprehensively by a number of scholars. Based on the existing cable supporting and unloading theory, this paper evaluates, the effect of secondary support of designing shear hole and its seismic performance simulated by pseudo-static method. And through the displacement response of key points in different elevations, the necessity of the shear hole has been demonstrated systematically. An evident cracking area has been found between cable support segment and shear hole support segment by studying the change of stress. Finally, some advises for later project monitoring are put forward.