煤层采动底板破坏规律动态观测研究

STUDY ON DYNAMIC OBSERVATION OF COAL SEAM FLOOR′S FAILURE LAW

煤层采动后顶底板应力状态发生改变,会产生一定范围的变形与破坏,不同煤层采动过程中的底板破坏具有一定的规律。对于受底板水害威胁的煤层,正确确定底板采动破坏深度是精确预测底板阻水能力的首要条件,因此通过实测法获得该破坏深度值及规律是矿井物探研究的一个方向。多年来,我国对煤层底板破坏规律的观测研究方法较多,但受技术条件所限,真正有效适用的技术方法较少。采用震波CT探测技术,结合煤层工作面中孔–巷间形成的探测剖面,进行不同时期震波CT数据采集、反演与资料处理,可获得煤层采动过程中底板破坏的动态发育规律及特征。开采探测实践表明,震波CT技术对底板破坏规律探测具有连续的动态效应,其适用性强,应用效果显著。

The coal seam floor′s distortion and failure would be found being because of the change of stress state after coal seam mining.The failure laws of the coal seam affected by mining are different.The exact failure depth of the coal seam floor is the primary condition to forecast accurately the capability of the floor to hold up water for the coal seam having the danger of floor water.So using the practical observation methods to get the floor′s failure depth and laws is a direction for the mine geophysical study.Many observation methods are studied to get the coal seam floor′s failure depth in the past decade years.But the effective observation methods are less because of the limitation of technique.The floor′s failure developing laws and characters can be gained by seismic wave CT combining with the detective section between bore and lane in the working face.It is shown that the failure laws are dynamic because the CT data collection and process are variable according to the mining schedule.Engineering practice shows that the seismic wave CT has notable effect on the failure depth detection of floor,and it has dynamic characteristic and better applicability.