白鹤滩水电站地下厂房位置及轴线选择设计

Underground Powerhouse Location and Axis Selection Design of Baihetan Hydropower Station

白鹤滩水电站地下厂房是典型的大跨度、高边墙巨型地下洞室群。工程区地质条件较复杂,柱状节理玄武岩发育,层间层内错动带形状差,地应力复杂。地下洞室群围岩稳定成为地下厂房位置及轴线设计的关键。综合考虑地质条件、枢纽布置等因素,对拟定的不同轴线方案采用FLAC3D软件对洞室群进行了数值开挖模拟,获得了洞周围岩变形特征及应力分布状态,推荐了最优的地下厂房位置及轴线方向,为枢纽布置格局确定奠定了基础。

The underground powerhouse of Baihetan hydropower station is giant underground caverns with large span and high sidewall.Geological condition of Baihetan project is complicated, columnar joints basalt developed, interlayer and inner layer shear zone with poor shape, geostress complex. Surrounding rock stability of underground caverns group becomes the key for designing underground powerhouse location and axis. Considering the geological conditions, project layout and other factors, the paper used FLAC3D software to simulate numerical excavation of the caverns under proposed schemes of different axis, got deformation characteristics and stress distribution of the cave surrounding rock, recommended the optimal position and axial direction of the underground powerhouse, laying basis for determining pivot layout pattern.