光照水电站坝基岩体质量检测研究

 光照水电站大坝为目前国内在建的最高的碾压混凝土重力坝。坝基开挖后，为复核坝基岩体力学指标，分析前期勘测设计工作的合理性，并考虑在适当的条件下对200 m级大坝的建基面进行优化，受业主委托，中国水电顾问集团贵阳勘测设计研究院对建基面进行了全面、系统的地质检测及岩体质量研究。此过程中采用了地质雷达、孔间声波CT、钻孔彩色录像、钻孔变形模量测试及钻探、压水试验、现场试验和室内物理力学试验等综合手段，获得了丰富的坝基岩体力学参数资料。结合地质编录资料，地质人员对检测成果进行了详细的地质分析。根据检测结果，该电站坝基岩石坚硬、岩体完整、岩溶相对不发育、地下水不甚活跃，坝基岩体具有足够的抗压强度、完整性、均一性，具有足够的抗滑稳定性及比较均一的岩体变形参数。经设计复核，除沿F1断层带需经专门处理外，前期所推荐大坝建基面高程的岩体质量及相关力学参数指标能满足坝基变形及抗滑稳定要求。

RESEARCH ON ROCK QUALITY DETECTION OF DAM FOUNDATION IN GUANGZHAO HYDROPOWER STATION

The dam in Guangzhao hydropower station is the highest roller compacted concrete gravity dam in China at present. To check the mechanical indices of rock mass in dam foundation，analyze the reasonability of the survey and design information in early stage is analyzed，and the possibility to carry out optimization about the foundation plane of the 200 m dam in proper condition is considered，entrusted by the owner，Guiyang Hydropower Investigation Design and Research Institute has carried out overall and systematical geological detection and rock quantity research on foundation plane after the foundation was excavated. In this course，geological engineers have adopted ground penetrating radar(GPR)，CT(computerized tomography) of sound wave among holes，the chromatic record of boreholes，deformation modulus tests of boreholes，drilling，water pressure tests，in-situ tests and physico-mechanical properties tests in the laboratory，etc.，getting mechanical parameters information of rock mass in dam foundation. Combined with the geological information，the results are analyzed. According to the results，the rock is hard and rock mass is complete in this dam foundation；karsts are relativly not developed，and the underground water is not so active. The rock mass in dam foundation has enough compressive strength，integrity and homogeneity with enough margin of stability to resist slip and relative homogeneous deformation parameters. Except for the region along fault F1 needing special treatment，the rock mass quality in the dam foundation in the elevation of foundation plane recommended in feasibility study stage and correlative mechanical parameter index can meet the requirement of deformation of the dam foundation.