马岩洞水电站特殊地质条件对水工方案选择的影响

Influence of special geologic conditions of Mayandong hydropower projecton the selection of the hydraulic alternatives

该电站为高坝长引水式开发。枢纽区地处岩溶高山峡谷地区，河谷地质结构总体属向斜走向谷，在其控制下形成河谷地形不对称和两岸高差大，以及巨型危岩体、顺向坡、碎裂结构岩溶含水层、岸坡卸荷拉裂缝、已建水库河床深厚覆盖层等特殊地质条件，对水工方案选择影响较大。在前期勘测设计过程中及时调整了设计方案，有效避开了它们的严重影响。

Mayandong hydropower project is composed of a high dam and a long diversion tunnel. The hydraulic complex is located in the karst area with high mountains and valleys, where the geological structure of the valley on the whole belongs to the synclinal valley. Under the control of the above geologic structure, the valley landform is dissymmetric and the elevations of the both banks have a great difference. At the same time, there are many special geologic conditions, such as huge dangerous rocks, consequent slope, karst aquifer of cataclastic texture, stress - release pull - apart joint of bank slope, and deep and thick cover on the river bed of the completed reservoir etc. The above mentioned geologic conditions greatly influence the selection of hydraulic alternatives. By timely adjusting the design alternative during the prophase investigation and design, the serious influence of these geologic conditions is effectively avoided.