金沙江干流水电工程区岸坡失稳危险性预测及防治对策

Risk evaluation and precautionary measures for bank slope instability in the hydroelectric project area on the mainstream of the Jinsha River

笔者通过调查研究和综合分析金沙江干流水电工程区岸坡地质背景和岩体力学环境条件,定性分析与定量评价相结合,采用与三峡工程库区岸坡失稳危险性评价相类比的方法,针对崩滑体失稳按总体积的1/8和1/11入江方量进行了计算和按美国土木工程学会涌浪图解计算法计算了入水点及在向家坝坝址、溪洛渡坝址和邻近城镇的涌浪高度,并围绕大坝施工安全、库区周边城镇安全,水库运营安全等方面对岸坡失稳的危险性进行了评价预测,提出了岸坡失稳的防治对策。评价结果表明,向家坝库区和溪洛渡库区土质岸坡坍塌及崩滑体入江和涌浪不会影响水库的正常运行及长期效益。

On the basis of a full investigation and study and an integrated analysis of the geological setting and rock-mass mechanical environment of the bank slopes of the hydroelectric project area on the mainstream of the Jinsha River and by combining the qualitative analysis with the quantitative evaluation, the authors calculated the instability of the sliding masses according to 1/8 and 1/11 of the total cubic capacity of the materials falling into the river and the surge wave heights at the falling sites as well as at the Xiangjiaba and Xiluodu dam sites and in adjacent townships according to the calculation method of the surge wave diagram given by the American Society of Civil Engineers, made the risk evaluation of the bank slope instability with respect to the operation safety at the dam, safety of the cities and townships around the reservoir and safety of the reservoir operation, and put forward precautionary measures for bank slope instability. The evaluation indicates that the collapse of the soil bank slope, falling of sliding masses into the river and surge waves in the Xiangjiaba and Xiluodu reservoir areas will not affect the normal operation and long-term effectiveness of the reservoirs.