杨房沟水电站深切河谷地应力场反演分析

针对杨房沟水电站坝区V型河谷地形地貌特征,结合坝址区地质构造条件,依据现场实测地应力成果资料,考虑河谷剥蚀下切演化对地应力场改造作用,反演得到坝址区初始地应力场,并将计算结果与实测值进行了对比分析。结果表明:计算结果与实测结果基本一致;杨房沟坝址区初始地应力场以NWW向水平构造应力为主,属中等地应力量级,岸坡浅表层一定深度范围内卸荷特征明显。研究结果为坝区边坡开挖及长期稳定性分析提供了重要依据。

Back analysis of initial geostress field in deep-cut valley of Yangfanggou Hydropower Station

In view of V-shape river valley features, geological condition at Yangfanggou Hydropower Station dam site, and considering the stress field reformation by river valley erosion and drop-cut evolution, the back analysis of initial geo-stress field at the dam site area was conducted and the results were compared with the measured ones. The results show that NWW horizontal tectonic stress, a medium grade, is dominant in the initial geo-stress field at the dam site; the unloading characteristic under slope shallow surface is obvious in a certain scope. The analysis conclusion can provide important basis for the slope excavation and long-term stability analysis.