锦屏一级水电站地下厂区破坏成因分析

DAMAGE MECHANISM OF JINPING Ⅰ HYDROPOWER UNDERGROUND STATION

锦屏一级水电站地下厂区位于雅砻江右岸一套大理岩地层中,埋深350m,地下厂区洞室在开挖过程中,围岩出现各种变形破坏现象。通过分析破坏现象,总结了破坏现象的规律性:主厂房及主变室破坏现象主要集中在下游边墙顶拱,破坏方式以岩体开裂为主;母线洞及压力管道下平段破坏现象主要集中在顶拱外侧,破坏方式以弯折破坏为主。最后利用数值模拟结果解释了径向应力大于岩体强度是引起锚索超限的原因。

Jinping Ⅰ hydropower underground station which buries in a depth of 350m,locates in marble strata.Varies failure phenomena can be found in surrounding rock under high ground stress during excavation process.Based on detailed description of those phenomena,obvious regularities are concluded and described as follows： fracture in top arch of underground station and voltage transformation station downstream sidewall;buckling in top arch of bus bar line cavern and penstock downstream plat part.At last why the anchor over load is explained using numerical simulation results that the radial force is far over the rockmass strength.