煤层开采底板承压水导升模拟试验系统研制与应用

为深入分析煤层底板承压水导升规律和直观展现突水通道形成过程,基于现有的二维相似材料模拟试验台研制了煤层底板承压水导升模拟试验系统。该系统包括二维相似模拟试验台(改造后)、承压水加载系统、承压水导升系统和计算机监测系统。运用研制的系统进行了尺寸为1 900 mm×220 mm×1 800 mm的模型铺设、开挖及监测。试验结果表明:该系统将柔性水囊、导水脉络和突水口组合成一个整体,避免了一般模型底板加载压力不均衡,解决了含压水箱与模型之间的密封难题;在水压达到0.03 MPa条件下,随着工作面推进距离增大,承压水导升高度不断升高,采空区中部出水量最大,导升高度最高;承压水沿阻力最小、距离最短的线路突出,且突水通道形成呈现突发、干脆特点;底板岩层受采动矿压和承压水水压产生的压剪作用,应力值出现"负—正—负"变化趋势。

Development and application of analogue testing system for floor confined water rise in coal mining

In order to deeply analyze the law of confined water conductivity and directly display the formation process of water inrush channels in coal seam floor，a simulation test system of confined water conductivity is developed based on the existing two-dimensional simulation test-bed of analogue materials.The system is composed of a two-dimensional simulation test-bed (improved)，a loading system of confined water，a system of confined water conductivity and a computer monitoring system.It has been applied into the laying，excavation and monitoring of the 1 900 mm×220 mm×1 800 mm model.The test results show that the system combines flexible water sacs，water conductivity veins and water inrush nozzles as a whole，which avoids the phenomenon of unbalanced floor loading pressure in general models and solves the difficult sealing problem between the water tank and the model;under the condition of 0.03 MPa water pressure，the height of confined water conductivity keeps on rising with the increase of working face distance and in the central gob the water yield is the largest and the height of the conductivity is the highest;the confined water bursts along the shortest route of the least resistance，and the formation process of water inrush channel is sudden and fast;the stress values show a changing trend of “negative-positive-negative” because of the compression-shear effect of the floor strata affected by mining pressure and confined water pressure.