小浪底水库左岸山体渗水途径分析及对策研究

小浪底工程左岸单薄分水岭山体的地质条件复杂,地层为砂岩夹有薄层泥岩,主要断层有F28、F461、F236、F238和F240。在左岸山体中布置有3条孔板洞、3条排沙洞、3条明流洞、6条引水洞、3条尾水洞、地下厂房、主变室、尾闸室以及为数众多的灌浆洞、排水洞、施工洞等,形成非常复杂的地下洞室群系统。水库蓄水后左岸山体出现了远大于原先估计的渗流量。本文根据观测资料及相关计算对主要渗水途径进行了分析,并提出了相应的对策。

Analysis on the percolation passes through the mountain at left bank of Xiaolangdi Project and the proposed countermeasures

A very complicated underground cavern system located in the thin mountain body on the left bank of the Xiaoliangdi Project is composed of a number of underground structures, including 3 orifice tunnels, 3 sediment tunnels, 3 free surface flow tunnels, 6 headrace tunnels, 3 tailrace tunnels, underground powerhouse, transformer chamber, draft tube gate chamber and also many tunnels for grouting, drainage, access and other uses. The formation of the strata is sandstone inter-bedded with thin layer mudstone. The main faults in the area are F_(28), F_(461), F_(236), F_(238) and F_(240). After impounding of the reservoir, the quantity of water discharge percolating from the left bank showed much larger than the pre-estimated value. A brief analysis of the main percolation passes on the bases of monitoring data and FEM calculation was performed. Necessary countermeasures were also proposed