南亚某水电站副坝漏水原因及整治方案

Leakage Reason and Improvement Method for Auxiliary Dam of a Hydropower Station in South Asia

南亚某水电站副坝为混凝土面板堆石坝,高77 m,坝基为侏罗系砂泥岩,当水位蓄至50多米时,坝体发生漏水,最大漏量达15.28 m3/s,临时采取坝前抛倒石块、砂砾石进行封堵,继而放空水库。漏水原因主要是趾板基础岩体风化严重,软弱,强度低,又未进行很好灌浆,致使趾板与岩体接触处发生接触冲刷,形成孔洞,导致面板开裂变形,造成渗漏。处理措施是封堵孔洞,修复面板和趾板,对坝体进行探查和补强灌浆,在趾板前增设齿槽。经过处理后,渗漏问题得到彻底解决,坝体再无渗漏点。

The auxiliary dam of a hydropower station,which is concrete face rock-fill dam with a height of 77m, is based on the Jurassic sandstone and mudstone. When pool level exceed 50m, the leakage occurred,with maximum amount of 15.28m^3/s. After taking the temporary treatments of filling stone and sand gravel in front of the dam,water of the reser- voir is all discharged. The causes of leakage including：basement of the dam is intense weathered rock with weak strength;Without high quality grouting construction to prevent the contact erosion between toe slab and rock. At last, it leaded the deformation and cracking of the concrete face. The final improvement method for leakage is to block the pores, repair the concrete face and toe slab, investigate the dam and strengthen with grouting, and construct additional sockets in front of the toe slab.