大柳树坝址位于规模巨大的活动断裂带内 ,岩体发生了大范围松动 ,表现为两岸岩体“风化”深度明显偏大 ,岩体质量指标偏低 ,岩体完整程度差 ,地下水位埋深大 ,岩体透水性强 ,岩体强度大幅度降低 ,岩体质量差。这些工程特性与同样外动力条件、同时代、同岩性、相距仅 48km的小观音坝址形成了巨大反差。由于区域断裂活动和松动岩体的双重制约 ,使得大柳树坝址区工程地质问题复杂化 ,不仅评价困难 ,而且处理难度大 The Daliushu dam site is located in a large-scale active fault zone, and the rock mass has loosened in a wide range. It shows that the depth of “weathering” of rock mass in both banks is obviously large, the rock quality index is low, the integrity of rock mass is poor, Deep, strong permeability of rock mass, a substantial reduction in rock mass strength, rock quality is poor. These engineering characteristics and the same external power conditions, the same generation, with the same lithology, only 48km away from the small Guanyin dam site formed a huge contrast. Due to the dual restriction of regional fault activity and loose rock mass, the engineering geological problems of Daliushu dam site area are complicated, not only difficult to evaluate but also difficult to handle