向家坝进水口高边坡系统锚杆受力状况研究

Mechanical analysis of systematic bolts on rock mass in high side slope at intake of Xiangjiaba Hydropower Station

向家坝水电站进水口高边坡地质条件较好,坡形较合理,设计拟采用系统锚杆对其进行加固。由于系统锚杆作用的被动性和边坡岩体变形的非均匀性,使得不同位置的锚件的应力出现较大的差别。利用有三维弹黏塑性有限单元法对向家坝进水口边坡中系统锚杆的受力状况进行了模拟和分析,从计算结果可以清晰地看出:边坡岩体不同部位的锚杆受力与被锚岩体的位移变形有一定的关系,而且设计采用的逐步开挖逐步锚固的施工步骤,使得先期锚入的锚杆受力随着后期开挖锚固的进行而逐渐加大。其计算结果为优化设计提供了依据。

The maximum height of the intake side slope of Xiangjiaba Hydropower Station is 150 m. Systematic Bolts will be adopted to reinforce the rock mass. Because of the passivity action of systematic bolts and the heterogeneity of rock mass deforming, systematic bolts have different stress in different position. This paper analyzes the systematic bolts＇ stresses on rock mass of high side slope of the intake in Xiangjiaba Hydropower Station by using elasto-viscoplasdc finite element method. We can find the obvious laws from the calculation results that the bolt stress is larger in the rockmass which has larger displacement than in one which has less displacement. And the bolt stress increases with the excavation and anchorage progresses.