向家坝水电站蓄水对大峡谷温泉的影响

On influence analysis after impoundment of Xiangjiaba hydropower station to Great Gorge hot spring

向家坝水电站蓄水以后,大峡谷温泉将沉埋在90 m深的库水下.如何正确评价水库蓄水对大峡谷温泉的影响成为了大峡谷温泉能否异地搬迁重建的关键问题之一.为此采用地质分析与数值分析相结合的方法,从多角度分析计算了向家坝水电站蓄水以后对大峡谷温泉的影响,分析计算结果表明:水库蓄水以后,库水不会通过淹没范围内所涉及的"天窗"(大岩洞-下河坝地区、湾湾滩断层和楼东断层)大量进入温泉水层,对温泉水量和水质影响较小.并且温泉井周边的围岩最大主应力增加0.47～0.60 MPa左右,水平位移增加量6～13 mm,影响深度80 m左右,井周岩石无明显的破坏现象.因此,水库蓄水对温泉井本身无大的影响,温泉可以进行异地搬迁重建.

The Great Gorge hot spring will under water that depth is 90 m after impoundment of Xiangjiaba hydropower station.The question,that how to evaluate influence after impoundment of Xiangjiaba hydropower station to Great Gorge hot spring rightly,is one of key point that if the Great Gorge hot spring can be relocated on other place.So the influence was analyzed and allaint from multi-way by combining geological analysis and numerical analysis.The result indicates： the influence that water of reservoir to spring water is very little because water of reservoir will not enter hot spring aquifer through ＂scuttle＂（Dayandong-Xiaheba area、Wanwantan fault、Loudong fault） largely after impoundment of Xiangjiaba hydropower station.The σ1 increment about 0.47~0.6 MPa and the increment of horizontal displacement about 6~13 mm,and the influence depth about 80 m in rock mass nearby hot spring well when water level is 380 m and sedimentation altitude is 320 m.At the same time,the plastic failure zone is little in rock mass nearby hot spring well after impoundment of Xiangjiaba hydropower station.The influence after impoundment to Great Gorge hot spring is very little and the Great Gorge can be relocated on other place base on scientific result of analysis and account.