一种新型钻孔压水试验压力控制设备设计与应用

Design and application of a new type of pressure control equipment for borehole water pressure test

为了探究煤矿开采对某拟建水库库区渗漏性的影响,通过现场钻孔压水试验测定岩体的透水性,以评价岩体的渗透特性。考虑到现场所用的供水设备为三缸往复式BW-250型泥浆泵,虽出水流量稳定性好,但其压力不易精确控制。为解决这一难题,组装一套开关阀门与安全阀串联的压力控制设备,以解决供水设备的压力问题,并在管路出口位置加装压力表和电子计量设备——电磁流量计,以准确计量累计流量和瞬时流量,压力表可对整个设备的压力加以验证,以防安全阀损坏或失效。试验结果表明,设备在使用过程中实现压力的平稳调整;岩体的透水性受煤矿采动影响较大,且随着距离的不断降低,透水率迅速升高,平均升高约5.82倍。

In order to investigate the impact of coal mining on the leakage of a proposed reservoir area,the permeability of the rock mass was determined by on-site water pressure test in borehole to evaluate the permeability characteristics of the rock mass.Taking into account the water supply equipment being three-cylinder reciprocating BW-250-type mud pump,although the water flow is of good stability,its pressure was not easy to accurately control.For solving this problem,a set of pressure control devices in series with on-off valve and safety valve was assembled to solve the unsteady pressure of the water supply equipment.A pressure gauge and electronic measurement equipment-electromagnetic flowmeter were installed at the exit of the pipeline,which can accurately measure the cumulative flow and instantaneous flow.The pressure of the entire equipment can be verified by the gauge to prevent the safety valve damage or fail.The test results show that:the device achieves a smooth adjustment of pressure during the process of application;the permeability of the rock mass is greatly affected by coal mining;and with the continuous decrease of distance,the permeability rate increases rapidly,with an average increase of about 5.82 times.