电阻率成像和钻孔电视技术在病险山塘查漏中的应用

土石坝填筑材料长期在水动力作用下易产生异常渗流现象,对病险山塘实施地质勘察是防渗方案优化设计的前提。鉴于对大坝渗漏病害的分布及诱因不明,钻孔的布置只能依据规范而定,却忽视了查漏的初衷,提出一种综合性、分阶段的大坝勘察技术。以胜岭脚山塘渗漏探测为例,利用电阻率探测技术圈定大坝病患的主要部位,并对渗流薄弱区进行钻孔注压水试验,进一步结合钻孔电视成像技术对孔壁大坝填筑质量进行分析。结果表明,电阻率成像技术可准确查明病害区的分布,孔内成像可直观反映钻孔岩土体的原状赋存特征,综合检测技术可有效解决大坝渗漏病症不清的难题,为除险加固勘察提供了新的思路。

Application of Comprehensive Investigation Method for Dangerous small Reservoir

The earth-rock dam filling materials are prone to generate abnormal seepage phenomenon under long-term hydrodynamic action,and implementing geological survey on dangerous small reservoir is the optimal design prerequisite of anti-seepage scheme.In view of the unknown distribution and incentives of dam leakage diseases,the arrangement of the drill holes can only be determined in the light of specifications;however, the original intention of leak detection is ignored.Therefore,a comprehensive and phased dam survey technique is proposed.Taking the Shenglingjiao small reservoir survey of danger removal and reinforcement as an example,the main reason for the dam leakage through the parallel electric method is that there is a weak zone in the contact zone of the left abutment.Based on this,the orientation of the borehole is guided.According to the results of the injection water test in the hole,and further downhole television to the hole-wall,the problem of poor quality and easy collapse of the dam is revealed.The final small reservoir dam design scheme is recommended to adopt the sloping wall anti-seepage reinforcement design.Engineering applications have shown that parallel electrical techniques can quickly identify disease areas.Combined with the targeted arrangement of the borehole and the downhole television technique,the hard problem of unclear illness is avoided, which provides a new idea for the survey of danger removal and reinforcement.