The Structural Features Of The Dislocation Interface Around The Dam Of The Jinsha River XiLuoDu Hydroelectric Power Station And It's Engineering Affects

There had grown a lots of dislocation interfaces in the Emeishan volcanic of Permian period in the dam area of the Jinsha river XiLuoDu hydroelectric power station being planned to build. The dislocation interfaces have great unslighting influence to the engineering stability of the dam. Basing on the acquaintence of the stratum, the rock, the structural setting, the tectonic framework and the research in the stratum, the rock and the structure of dam area in detail, using the modern principle of tectonic analysis, this paper analyzes the geometry characteristics, the deformation characteristics, the dynamics characteristics, kinematics characteristics of the dislocation interfaces. Further more this paper discuss' the structural generation, the structural sequence and the structural evolution of the dislocation interfaces.The dislocation interfaces, which have different directions, different combinations, different scale, different deformation strength and different properties, are belonged to shallow structure. They are the products of multi-stages, multi-periods and multi-causes of movement during the Himalayan Epoch. They were controlled by and resulted from 2 structural stress fields of NE structure and NW structure.There are lots of primary structures, such as bed interfaces, lagerklufts and diagonal joints, in the Emeishan volcanic, which dislocated to be dislocation interfaces later. Especially in those primary structures that were filled with the epidote- quartz vein, the dislocation interfaces are more aptter to grew.The formation of the dislocation interfaces keeps close relation with the areal structures and the tectonic stress fields of the areal structure. The dislocation interfaces of early stage were controlled by the slide of the NE fold. The dominant dislocation interfaces, in the dam area, is the one of the second stage, which resulted from the slide of the lava layer and lagerkluftes from NW to SE because of the affect of the MaJiaHeBa faultage's thrusting overriding to the dam area from NW to SE. The dislocation interfaces of the third stage were the result of the overprint of the structure of NE to the one of NW.Through the all-sided tectonic analyses, it can be deduced that there are two aspects will be the hidden defects to the dam and the engineering stability of the reservoir area. One is the dislocation interfaces resulting from the the MaJiaHeBa faultage's thrusting overriding and other causes of formation. The second is the region of strong deformation, such as the above of the dam, middle and high positions of the lava layers and the regions of overprint of the structure of NE to the one of NW, which should be taken into account especially.