青海某水利工程坝基地质条件与截渗墙施工管理研究

Research on Geological Conditions of Dam Foundation and Construction Management of Cutoff Wall of a Water Conservancy Project in Qinghai Province

【目的】水利水电工程坝基深厚覆盖层地质条件对坝基渗漏有重大影响,需要研究深厚覆盖层地层岩性及其工程性质指标。【方法】以青海某水利工程为例,采用地质钻探、现场试验、地质综合分析的方法,对坝基深厚覆盖层进行了详细分层,查明了该工程大坝坝基深厚覆盖层的地质条件。【结果】结果表明,深厚覆盖层的地层、岩性复杂多变,可能造成坝基渗漏问题,必须采用截渗墙进行坝基处理。【结论】结合深厚覆盖层地层、岩性特征,提出了坝基截渗墙施工中要重点关注施工过程的塌孔、漏浆、截渗墙墙体深度及厚度、墙体材料等问题,并针对截渗墙施工中可能遇到的问题提出了相应的对策。研究成果可为类似深厚覆盖层截渗墙设计与施工提供一定的参考。

[Purposes]The geological conditions of the deep overburden layer in the dam foundation of water conservancy and hydropower projects have a significant impact on the leakage of the dam foundation.It is necessary to study the lithology and engineering property indicators of the deep overburden layer.[Methods]This study takes a water conservancy project in Qinghai province as an example,and uses geological drilling,on-site testing,and comprehensive geological analysis methods to conduct detailed layering of the deep overburden layer of the dam foundation.The geological conditions of the deep overburden layer of the dam foundation of the project are identified.[Findings]The results show that the strata and lithology of the deep overburden layer are complex and variable,which may cause leakage problems in the dam foundation.Therefore,it is necessary to use cut-off walls for dam foundation treatment.[Conclusions]Combining with the formation and lithology characteristics of deep overburden,it is proposed that the construction of dam foundation cutoff wall should focus on the problems of hole collapse,slurry leakage,depth and thickness of cutoff wall,wall materials and so on.The corresponding countermeasures are put forward for the problems that may be encountered in the construction of cutoff wall.Research findings can provide some reference for the design and construction of cutoff wall with similar deep overburden.