基于单孔稀释试验的人工湖渗漏探测方法及应用

Method and application of artificial lake leakage detection based on single-borehole dilution test

渗漏是影响湖库安全的关键因素,对其进行准确、高效探测一直是水工安全领域中的技术难题。与基于电磁理论的地球物理探测技术不同,基于井流理论的单孔稀释技术可以直接得到与渗流场相关的含水层参数且无需额外的参数转换。但传统的单孔稀释试验往往仅对点位渗漏性进行定性判断,针对大尺度下渗漏规模的定量分析应用较少。为此,基于单孔稀释测速原理对四川省仁寿县某渗漏人工湖进行研究。在人工湖附近钻孔后进行单孔稀释试验,通过监测NaCl溶液电导率数据得到钻孔流速,通过解译流速数据得到了人工湖最大渗漏通道位于湖体左侧钻孔ZK6~ZK7区域420~440 cm深度范围和ZK8区域300~400 cm深度范围,钻孔剖面渗流量为4.24 cm^(3)/s。现场试验应用表明:单孔稀释法不仅能定性分析出渗漏通道的空间位置,还能定量计算出地下流速、渗流量参数。试验证明单孔稀释渗漏探测原理应用于湖库渗漏探测中具有较好的推广应用价值。

Leakage is the key factor affecting the safety of lakes and reservoirs,its accurate and effective detection has always been a technical problem in the field of hydraulic structure safety.Unlike electromagnetic theory based on geophysical detection technology,the single-borehole dilution technology based on the well-flow theory can directly obtain the aquifer parameters related to the seepage field without additional parameter conversion.However,traditional single-borehole dilution tests often only qualitatively judge the leakage at a point,and there are few quantitative analysis applications for detection under a large area.Therefore,we used the single-borehole dilution velocity measurement principle to investigate the leakage problem of an artificial lake in southwest China.The single-borehole dilution test was conducted after drilling near the artificial lake,and the drilling flow rate was obtained by monitoring the NaCl solution conductivity data.By analyzing and interpreting the flow rate data,it was found that the largest leakage channel of the artificial lake was located in the depth range of 420~440 cm in the ZK6 to ZK7 area and the depth range of 300~400 cm in the ZK8 area on the left side of the lake,with a drilling profile seepage flow of 4.24 cm^(3)/s.Field experiments show that the single-borehole dilution method can not only qualitatively analyze the spatial location of the leakage channel,but also calculate the parameters of velocity and seepage flow.This accurate and efficient technique can be applied to the leakage detection of lakes and reservoirs.