济南章丘区某黏土矿采空区勘查和注浆治理

The Investigation and Grouting Treatment for a Mined-out Area of Clay Mineral in Zhangqiu District of Jinan

济南市章丘区一典型的黏土矿采空区场地,场地内有两处已关闭的黏土矿采矿点,开采的矿层为二叠系石盒子组(B层)上部耐火黏土矿层。查明采空区分布范围和规模,并对其进行妥善处理,是建筑施工前的首要任务。在矿区工程地质调查的基础上,先后采用了大地电磁测深物探和钻探手段,查明了采空区分布的深度段,并圈定了采空区平面治理范围。大地电磁测深工作沿建筑范围的东西两侧60 m长边各布设1条测线,验证钻孔3个。依据规范进行注浆方案设计,详细确定了采空区处理面积范围、工程量和注浆压力等参数,相关技术工作流程和工程经验对黏土矿和小型煤矿采空区治理的具有一定的适用性,可为类似工程项目提供参考。

A proposed project site is at the typical mined-out area of the clay mineral in Zhangqiu District of Jinan.Within the project limits,there are two clay mining sites that had a production period between 1999 and 2014.The mine layer called Layer B was the top of the Permian Shihezi Formation.So,it is critical to identify the distribution range and scale of the mined-out area and to treat it appropriately before the construction.Based on a geological study of the mining area,the geophysical prospecting by using magnetotelluric sounding and exploratory drilling to verify the depth section of the goaf distribution and delineate the plane range for treatment were successfully implemented.A 60-meter survey line was located on both the east and west sides for the magnetotelluric sounding.Then three(3)boreholes were drilled for the verification.According to the Technical Code,the grouting system,in which the treatment area of mined-out area,the amount of work and the injection pressure were determined.The technical workflow and the experience of this project have some applicability in the treatment of the mined-out area extracted from the clay minerals and from the small mines.