病险土石坝水力劈裂现象的注水试验研究  

Research on Hydraulic Fracturing Caused by Water Injection Tests in Dangerous Earth-rockfill Dams

作　　者：江晓益[1] 孙伯永[1] 陈星[1] 

机构地区：[1]浙江省水利河口研究院,杭州310020

出　　处：《中国农村水利水电》2010年第6期143-146,149,共5页China Rural Water and Hydropower

摘　　要：对病险土石坝坝体注水试验过程中的水力劈裂现象及其原因进行了分析。研究表明,大坝防渗体为低渗透性时,在高水头下的水力劈裂发生的风险相对要大。坝体的应力分布中小主应力3σ不足是引起坝体水力劈裂的主要原因,在1/3~2/3倍坝高处,小主应力和土的抗拉强度之和往往不能抵抗过高的水头压力而引起水力劈裂。坝体钻孔注水试验应尽量控制水头上升速度,并实时监测水头与流量的变化,选择较低的水头进行试验,并采用分级注水,在判断试验结果未发生水力劈裂的情况下,取合理的试验结果的平均值作为最终试验值。In this paper,the phenomenon of hydraulic fracturing caused by water injection tests in dangerous earth-rockfill dams is analyzed.It is proved that the risk of hydraulic fracturing with high-head water injection tests in the low permeable dam is larger.The cause of hydraulic fracturing is the lack of the minor principal stress-σ-3 in stress distribution of the dam.The sum of the numerical values of minor principal stress and tensile strength of the soil are often unable to resist high water pressure in the 1/3~2/3 times of the dam height.The water injection test should control the rising speed of water head,and monitor the changes of water head and flow.It is advised to choose three different low-head water injection tests,and take a reasonable average of test results as the final test value.

关 键 词：土石坝 注水试验 渗透系数 水力劈裂 

分 类 号：TV221.2[水利工程—水工结构工程]