以牙根水电站为例,采用节理玫瑰花图法分区统计并对比分析了坝区左岸及右岸39个平硐2 000多条节理,认为坝区发育的大量结构面为NW向的左行扭动在岩体中派生的节理,并分析了缓倾角结构面分布特征,指出Ⅱ-Ⅲ级结构面的限制作用而导致其不稳定与连续性差、不同级别的松动岩体结构面间具有牵动制约的发育规律。 Taking the Root Canal Hydropower Station as an example, more than 2 000 joints of 39 adit holes on the left bank and right bank of the dam area are analyzed and compared by using the joint rose plot method. It is considered that a large number of structural planes developed in the dam area are twisted in the NW direction The derived joints in the rock mass are analyzed, and the distribution characteristics of the structure surface of the gentle dip angle are analyzed. The results show that the Ⅱ-Ⅲ structural plane has the limitation of instability and continuity, and the structural planes of the different levels of loose rock mass have restricted development law.