摘要
煤层底板破坏深度规律是承压水上安全开采决策的重要依据。以往的研究过程主要通过压水试验、数值模拟和相似材料试验等方法探测其深度。近年来，CT探测等物理学手段不断被引入到矿井岩体的破坏程度探测研究中。剪切波速测试作为一种原位测试手段，过去仅在地表条件下适用。在兖州田庄矿平均煤厚1.2m，煤层底板距十四灰20～25m，距离奥陶系灰岩含水层50m的条件下，通过数值模拟、采前采后2个测点的底板破坏声波测试综合分析了11703面底板采动拉应力、塑性区、塑性状态变化的基本规律，得到了薄煤层采后严重扰动区、明显扰动区和影响区的分区规律。声波测试结果表明：明显扰动区与声波测试破坏下限深度基本一致，且研究结果已应用于11703工作面开采决策。
The law of bottom failure depth is the key reference to safety decision in mining above confined water. Usually, research on the failure depth of coal seam floor is performed through water injecting into cracks caused by mining, numerical simulations, and similitude material experimentation, etc.. Recently, CT and other physical methods are used to measure the integrality/damage of rock mass, even in some coal mines. Shear wave velocity is an in-situ test method and suitable for carrying out on the surface. The trial is made to gain the bottom failure depth in work face 11703 of Tianzhuang coal mine, which is beneath the coal seam No. 17 with a thickness of 1.2 m in average and a distance of 20～25 m to No.14 limestone, and about 50 m away from Ordovician limestone. The test is performed before and after mining in two locations, each lying in the roadway of the workface. Accordingly, a plane of stri^e direction and two planes of incline direction through the testing locations are ascertained to simulate the mining process; and the distribution of tensile stress, plastic area, and variation of plastic zones are analyzed, from which the failure area of coal seam can be divided into severely destroyed area, obvious disturbance area, and affected area. Simultaneously, the distinct variance points of wave velocities recorded before and after mining are at the depth of 13.27 m and 13.63 m, respectively, with which the simulation results agree well. Then the conclusion can be made that the failure depth is shorter, about 11 ～ 12 m, in the middle of workface and longer, about 13.5 m at the edge of working face. The results show that shear wave velocity method is reliable to detect the failure zones in the bottom of coal seams in the working face 11703.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2005年第A01期5237-5242,共6页
Chinese Journal of Rock Mechanics and Engineering
基金
中国矿业大学青年科技基金资助（0F4467）
关键词
采矿工程
薄煤层
波速测试
数值模拟
底板采动影响深度
mining engineering
low coal seam
acoustic wave measurement
numerical simulation
floor affecting depth during mining
