Design and application of a new type of pressure control equipment for borehole water pressure test
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,al-though 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 wa-ter 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 a-chieves a smooth adjustment of pressure during the process of application;the permeability of the rock mass is greatly affect-ed by coal mining;and with the continuous decrease of distance,the permeability rate increases rapidly,with an average in-crease of about 5.82 times.
borehole water pressure testpressure control equipmentpermeabilityengineering application
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维普
