陡倾坡内和垂直坡面走向张裂隙共生的成因机制及其工程效应

西南某水电站坝区右岸不但发育陡倾坡内并与坡面走向大致平行的张裂隙和断层也有一系列倾角近于直立与坡面走向近于垂直的张裂隙。这两组裂隙在同一边坡内同时出现,在国内已建的大型水电工程边坡中尚未见报道。研究表明,这一组合是由于右岸西侧穹隆新生代以来发生过较强烈隆升导致放射状和环状张裂隙同时发育的结果。正是由于两组张裂隙的存在,使边坡岩体深强风化发育,从而降低了坝肩岩体的强度。

THE GENETICMECHANISM OF THE TENSION FRACTURE PARAGENESIS DIPPING TOWARD TO THE INNER SLOPE ANDPERPENDICULAR TO THE SLOPE STRIKE AND THEIR ENGINEERING EFFECTS

The fractures in the right bank of some dam are composed of the tension fractures dipping toward to the inner slope and perpendicular to the slope strike. The fracture composition has not been seen in the slopes of the constructed hydropower stations in China. Our study shows that the reason of the fracture composition is the quick uplifting of the vault in Cenozoic and formation of radiated and circular fractures. As the tension fractures exist, spread and deep weathering is strong, which causes the lowing of the strength of the engineering slope.