综合勘察技术在天开水库渗漏分析中的应用研究

采用地质测绘、地质钻探、综合地球物理探测和水文地质试验的综合勘察技术对北京天开水库渗漏进行了分析评价。查明了古河道位置及空间特征、坝基基底地层结构特征、库区基岩的溶蚀裂隙发育程度及构造带产状、库区集中渗漏点和渗漏区。综合分析认为:库区内现代河道及附近覆盖层受蓄水后的潜蚀破坏,形成了一定漏水通道;副坝古河道内分布的卵砾石层也形成了水库渗漏通道;库区基岩层的渗漏区和集中渗漏点为水库渗漏的主要通道,呈北西—南东向贯穿整个库区并向库外延伸,其他小部分的渗漏可能是库水经岩溶裂隙向库区更深部的渗漏。研究成果可以为天开水库后续防渗工作和工程建设服务,同时提出的分析方法可以为其他水库勘察提供一定的借鉴与参考,也为综合技术在岩溶地区勘察的广泛应用起到推广作用。

The application of comprehensive survey technology in seepage analysis of Tiankai reservoir

The leakage of Beijing Tiankai reservoir has been analyzed and appraised using the comprehensive survey technology of geological surveying and mapping, geological drilling, integrated geophysical and hydrogeological tests. The location and spatial characteristics of the ancient river course, the structural characteristics of the basement of the dam foundation, the development of the dissolution fissures of the basement rock in the reservoir area, the occurrence of tectonic belts, the concentrated leakage and leakage areas in the reservoir area have be identified. The comprehensive analysis shows that the overburden of the modern river courses in the reservoir area are damaged by the potential erosion after water storage, forming a certain water leakage channel. The pebble layer of the ancient channel in the secondary dam also forms the leakage channel of the reservoir. The leakage zones and central leakage points of bedrock layer of reservoir area are the main leakage channel of the reservoir, which runs north-west to south-east through the reservoir area and extends to the outside of the reservoir. The leakage of other small part may be caused by reservoir water going deeper into the reservoir area through karst fracture. The research results of this paper can play a scientific guiding role in the follow-up seepage control and engineering construction of Tiankai Reservoir. At the same time, the analysis methods of this paper can provide some reference for other reservoir surveys. It also plays a good role in promoting for the wide range of applications of comprehensive technology in karst area survey.