孙村矿采场下伏岩层矿压显现

Rock Pressure Manifestation in Underlying Rock Strata below workings in Suncun Colliery

孙村矿2层煤1212回采工作面,距地表垂深580～630m,煤层倾角23°～25°,煤厚3.55m,上分层采高1.7m左右。采煤方法为走向长壁后退式冒落法。上组煤(2、3、4、6层)联合开拓布置。采区运料上山在6层煤中,回风上山在4层煤中。4～6层用石门联络,间距40m;4～2层用反井联络,间距17m。为了摸清600m深度上面采场对下伏岩层的影响,在6层石门及4层回风上山中,分别设5个测点进行巷道变形观测。Ⅰ、Ⅱ号测点设在石门内(图1)。

the behaviour of underlying rock strata below working is discussed in detail in several aspects,as vertical distance,location of roadways,the horizontal distance from roadway to the coal face,and the rock type.They are as follows:1.the vertical distance from roadway to coalface has a direct bearing on the deformation of the roadway.Observations indicate that the greater the vertical distance,the smaller the deformation,and the vice versa.2.When the vertical distance being equal,deformation of the roadway varies with the location of the roadways.Under specific conditions of No.1212 face in Suncun the deformation is the greatest when the roadway below workings is at the top of the face;and deformation is the next when the roadway is at the middle of the face;and deformation is the least when the roadway is at the bottom of the coal face.3.the horizontal distance from roadway to coal face also affects deformation of the roadway,the shorter the distance,the greate r the deformation.4.the deformation is different when the type of surroundiug rock changes.Based on the measured results,deformation is small when the rock is hard,and is great when the rock is soft.