水压式双栓塞止水压水技术的研究与实践

Research and application of the hydraulic double plugsealing water injection test technique

国内工程钻孔压水多结合造孔采用单栓塞止水,按0.3、0.6和1.0MPa3个压力点5个压力阶段进行试验,我们称其为常规压水试验。目前,进行勘测设计和施工的高坝高水头电站、抽水蓄能电站已有多座,查明岩体在实际水头作用下的透水率和渗透特性是工程设计的一项重要工作。因为一些低压力下不渗透的岩层在高压下可能渗透甚至会产生水力劈裂,常规压水试验结果已不能完全满足工程设计的需要。为此,我们研制了水压式双栓塞止水压水技术。实践证明,该技术具有止水效果好、操作简单、可在终孔后连续进行试验等优点。本文给出了使用该技术进行的常规压水、高压压水和水力劈裂三个方面的试验资料,简单分析了这些试验资料在工程设计中的作用和意义。

In most engineering fields water injection tests are often conducted by single plug sealing with three pressure point, i.e., 0.3, 0.6 and 0.9 MPa, and five pressure steps. This is called a common water injection test. At present there are some hydro-powers and pumped storage stations with high water heads, and it is important to evaluate the rock infiltration properties under practical water pressure, because any terranes which were water-tight under low water pressure will probably became leaky even hydraulic splitting under high water pressure. Thus the common water injection test has already not entirely met the demand of such engineering constructions. A technique named hydraulic double plug sealing water injection test is developed in this paper. The system structure is introduced and its application to some hydro-powers with the results of three type test as common water injection test, high pressure water injection test and hydraulic splitting test are discussed, and the significant effect on project designs is also evaluated.