浅埋煤层的矿压特征与浅埋煤层定义

GROUND PRESSURE BEHAVIOR AND DEFINITION OF SHALLOW SEAMS

根据3个不同条件的浅埋煤层工作面矿压实测,得出了中国特大浅埋矿区顶板破断规律与普通采场不同,主要特征是顶板切落式破断和台阶下沉,顶板垮落一般形成冒落带和裂隙带。并初步提出了以关键层、基载比和埋深为指标的浅埋煤层定义,为正确建立顶板结构模型和进行顶板控制奠定了基础。

By field observation in three longwall faces with different shallow overburden,the ground pressure behavior and the basic law of roof weighting are revealed. It is found that the strata breaking runs though whole roof,and there are big roof steps pushing in face during roof weighting. Shallow seam roof can not form stable roof block structure,and it will cause obvious roof pressure. It is also found that there are only two zones forming after strata collapse,the caving zone and the cracked zone. Speeding up face advancing is propitious to roof stability. Finally,the shallow seam definition for strata control is put forward by use of three key index,the key stratum,the thickness ratio of rock to soft overburden and the depth of coal seams.