深埋煤层开采的离心模型试验研究

 以菏泽井田赵楼煤矿近千米深埋煤层首采区地质条件为依据，通过离心试验研究采动影响下，煤层顶板不同位置的应力变化规律，结果表明：(1) 开切眼处煤柱处压力随煤层的采动不断变化，对其压力产生明显影响的是前方约35 m煤层的开采，最大应力集中系数为2.04；开挖工作面前方10～15 m煤层支承压力集中，最大应力集中系数为2.8。(2) 直接顶处岩层压力随煤层的采动不断变化，在工作面处达到峰值，最大应力集中系数为1.74，工作面推过后，其压力下降后又有所回升，为上覆岩层重新压实所致。(3) 老顶岩层压力亦随煤层开采不断变化，但其峰值出现在工作面推进后5～10 m，最大应力集中系数高达3.91，在煤层开采过程中，要加强观察和支护，预防冲击地压等灾害的发生。(4) 综合得出赵楼矿井老顶的初次断裂步距约为30 m。试验结果可为煤炭深部开采条件下的岩层控制、合理的巷道布置、改善巷道支护和维护情况及冲击地压的预防提供依据。

RESEARCH ON CENTRIFUGAL MODEL EXPERIMENT OF DEEP-BURIED COAL SEAM

Considering the geotechnical conditions of the Zhaolou coal mine,similitude material centrifugal experiment is done,and the stress variation at different positions in coal seam roof is found. The following results have been drawn. (1) Because of the excavation of coal,the pressure variation of coal pillar is evident,the influencing distance is about 35 m,10-15 m ahead the working face;and the maximum pressure concentration coefficient is produced,which reaches 2.8. (2) The pressure of immediate roof reaches its peak value,which is 1.74,immediately when the working face arrives;and it decreases firstly and then rises after the working face passes. (3) The peak value of the pressure of the basic roof occurs after 5-10 m excavation of coal,and the corresponding maximum pressure concentration coefficient reaches 3.91 on the condition of basic roof. Therefore special measures must be carried out. (4) The step of rupture on the basic roof is about 30 m. The research results are important to the design of coal channel,the excavation,and the prevention of geotechnical disaster.