曲江煤矿地表塌陷成因时空关系分析

摘要

In order to research the mechanism and reasons of surface collapses in Qujiang Mine,based on the data of the temporal and spatial characteristics of surface collapses,the results of geological exploration,the seasonal change law of annual precipitation,the record data of earthquakes and the conditions of coal mining in Qujiang Mine,the temporal and spatial relationship analysis between causes of nine surface collapses and several factors was carried out,including underground caves,precipitation,earthquakes and mining.The results showed that soil caves existed around surface collapses,the burial depth and relative distance mostly less than 20 m,so the underground caves in shallow and thin cap rock were essential internal cause of surface collapses,and in March,the water level was minimum,the precipitation were at most from April to June,occurring seven collapses,so the groundwater lowering and cap rock weakening in rainy season were direct external cause,moreover the interval time between occurring collapses and earthquakes was within 3 months,except No.1 surface collapse,so earthquakes were induced external cause,finally,the correlation between underground mining and surface collapses was not obvious,but the location of surface collapses was influenced by mining.%为了研究曲江煤矿地表塌陷机理和原因,基于本区地表塌陷时空特征、地质勘探结果、年降水量季节变化规律、地震记录数据、煤矿开采条件等资料,对该矿9处地表塌陷成因与地下孔洞、降水量、地震、开采等因素进行了时间与空间关系分析.研究表明:地表塌陷周边存在土洞,且埋深与相对塌陷距离多数在20 m以内,浅部存在孔洞和盖层薄是地表塌陷的本质内因;每年3月水位最低,4-6月降水量最多,共发生塌陷7处,地下水位下降和雨季盖层弱化是地表塌陷的直接外因;塌陷发生时间(除1号塌陷)与地震发生时间前后间隔均在3个月之内,地震是地表塌陷的诱发外因;井下开采与地表塌陷的相关性不明显,但对地表塌陷位置存在采动影响.