北本水电站区域构造稳定性评价分析

Evaluation and Analysis of Regional Structural Stability of Beiben Hydropower Station

介绍了北本水电站区域地形地貌、地层岩性,重点研究了北本水电站区域断裂活动性、区域地震活动性、工程场地地震安全性。工程区位于横断山系南端,广泛分布石炭系中统~侏罗系中统地层,局部出露白垩系上统和上第三系~第四系以及华力西期的花岗岩。近场区3条活动断裂,仅有1条断裂具备发生6.5级地震的构造条件。场区4条Ⅲ级断层不具有发生强震的构造条件和不存在发震断裂错动问题。地震危险性主要来自近场磨县—班谷保、会晒—班更谷和琅南塔—勐腊3个潜在震源区的强震。

This paper describes the regional topography,geomorphy and stratigraphic lithology of Beiben Hydropower Station,with a focus on the study of regional fracture activity,regional seismic activity and seismic safety of the project site.The project area is located in the southern end of the Hengduan Mountains,and extensively distributes Carboniferous-Jurassic strata,with locally exposed Cretaceous Upper Tertiary-Quaternary and Warwick granites.There are 3 active faults in the near field area,only 1 fault has the structural conditions for M6.5 earthquake.Four M3 faults in the field area do not have the structural conditions for strong earthquakes and do not have the problem of dislocation of seismogenic faults.The seismic risk mainly comes from strong earthquakes in three potential source areas:Moxian-Bangubao,Huishai-Bangenggu and Langnanta-Mengla.