土坝坝体注水试验的影响因素

针对目前病险土坝地质勘察中选取坝体土渗透系数较难的问题,采用适合土坝坝体注水试验的渗透系数计算公式,分析了注水试验参数对渗透系数的影响,并对常水头与降水头室内渗透试验与现场注水试验成果进行对比分析。结果表明:土坝坝体注水试验水头和初始水位对试验结果影响最大,注水试验水头过高易产生坝体水力劈裂,造成坝体土渗透系数偏大的假象;大坝坝体填土均适合进行常水头及降水头注水试验;土坝坝体土渗透系数的确定应综合注水试验及室内渗透试验的成果。

Influencing factor analysis of water injection test in earthfill dam

Considering the difficulty of determining the hydraulic conductivity of a dangerous earthfill dam during geological investigations,the influence of a water injection test on hydraulic conductivity was analyzed using the hydraulic conductivity calculation formula which is suitable for a water injection test in an earthfill dam.The results of stable-water-flow and flexible-water-flow laboratory permeability tests were analyzed and compared with those of field water injection tests.The results show that the water head and initial water level of the water injection test have the largest influence on the test results.Hydraulic fracturing in the dam occurs easily under high-head water in water injection tests,leading to a larger permeability than the real one.The filled soil of the dam is suitable for stable-water-flow and flexible-water-flow water injection tests.The hydraulic conductivity can be determined through water injection tests and laboratory permeability tests.