| Yalong River upstream Geni hydroelectric station is located5km the Ganzi County velvet dam, Qu River huikou, Township bifurcated upstream reach, comprehensive information, Geni Hydropower Station has excellent conditions for the development and prospects. However, this area is located in Songpan-Ganzi orogenic belt, from the Xianshuihe fault zone, Ganzi-Yushu fault zone close to the complex tectonic setting, seismic activity is strong, the Cenozoic orogeny strong, the region folds, faults are developed. Basic geological research has accumulated a certain amount of information and results, and lay the foundation for further study, but overall, remained weak in basic geological research, Ganzi-Litang with property, Ganzi-Yushu fault activity works; regional stability evaluation of the project area and so on the follow-up research and design has a certain influence.Songpan-Ganzi orogenic belt north western part of Geni hydropower project area is located in the eastern margin of the Qinghai-Tibet Plateau, across the Ganzi-Litang combined with passive margin tectonic belt and Yidun island arc with a tectonic units, complex tectonic setting.Project area harsh weather conditions, traffic conditions, complex geological structure, so closely related to the basic geological research and engineering, especially in geological formations-such as fault development, distribution characteristics, the deformation characteristics, traits, activities and hydropower the works are not for the system in-depth study, which directly affect the adaptability evaluation of the project design and construction. Therefore, the evaluation of active faults in the region and the stability of the project area for the proposed Geni Hydropower Station site and the dam site comparison and selection, design and construction of such great importance.In this paper, the geometry of the geological structure, Transfiguration, dynamic analysis, integrated use of various means of remote sensing geology, engineering geology, geophysics, earthquake geology, comprehensive project area. The focus for the the close geological structure and engineering geological, seismic and geological research.Dam site of the main fault activity, in addition to the field on the basis of fracture Geological Survey, also the use of the ESR comprehensive study, SEM, and other methods. As the field geological investigation found no fracture in the dam site area has the characteristics of active faults, and the SEM experimental data show that the age of dam site of fracture latest activities in the early-before the Pleistocene; Finally, ESR dating data obtained Dam Area The major faults Last age older than13million years. In summary, the results of various methods are consistent, that is all the breaking of the dam site area, be active.The fracture region active in regional stability evaluation, studies suggest that fracture of the dam site, be active, but its density, also has a certain impact on the project. Faults developed within the near-field region (20km range), particular concern Ganzi-the Yushu fault Holocene active faults, a greater impact on the project. The combination of seismic data, historical earthquake intensity of Ⅷ degree of impact on the project site, Geni earthquake peak acceleration to0.20g. According to the regional tectonic stability evaluation criteria, belong to the poorer areas of the regional tectonic stability.Dam site comparison, according to the dam site topography, lithology, tectonic features on the upper and lower dam site Selection Geni dam site of the upper and lower dam site section similar topography, formation lithology similar, but different in structure influencing factors on dam segment structure is relatively simple.The complex structure of the dam site section and gently inclined cracks and geothermal relatively developed. Comprehensive above the dam site for the representation of Geni hydropower dam site. |
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