基于宁波大榭岛熔结凝灰岩地区的压水试验改进

Improved water pressure test and its application in Daxie island(Ningbo)tuffs area

压水试验是测试深部岩体渗透性的重要方法之一。通过改进压水试验,如安装推拉阀门精简设备,在试段内安装探头直接测取试段压力,在压水泵和压力计之间安装水阀将压水试验转为脉冲试验等,在宁波大榭岛致密凝灰岩地区进行试验,对比分析了改进前后的测试效果。结果表明,理论计算的试段压力与实际存在一定差异,使用探头获取的试段压力排除了管损压力、孔内水位变化等因素的干扰,使得渗透系数的计算更准确;在低渗透性试段内,脉冲试验能测得小于1.0×10^-5 m/d的渗透系数,更加精确。这些改进提高了压水试验的效率和精度,并拓展了试验设备的应用范围,对于岩体渗透性评价具有一定参考价值。

The water pressure test is one of the important ways to test the permeability of deep-buried rock mass.In this paper,the water pressure test method was improved by installing the push-pull valve to simplify the equipment,installing the probe in the test section to directly measure the pressure,and installing a water valve between the pressure water pump and the pressure gauge to convert the water pressure test into a pulse test.The improved method was then applied to the measurement of the permeability in a tuffs area of Daxie island(Ningbo).The test results before and after the improvement of the method were analyzed and compared.The results show that the test section pressure obtained from theoretical calculation is different from the actual pressure.The test section pressure obtained by the probe excludes the interference of the tube damage pressure loss and the water level change in the hole so that the calculation of the permeability coefficient is more accurate.In the test section with a lower permeability coefficient,the pulse test can measure the permeability coefficient less than 1.0×10^-5 m/d,which is more accurate.By increasing the efficiency and precision of the water pressure test and expanding the application range of the test equipment,the above improvement has certain reference value for the evaluation of rock mass permeability.