针对在条带开采煤柱尺寸设计中大多数是采用强度稳定性分析的方法,而没有考虑弱面对煤柱稳定性的影响,由于弱面的存在,煤柱常常会因抗剪强度不够而产生剪切破坏等问题。采用分析计算的方法,根据煤柱弱面的剪切强度来设计条带开采煤柱的尺寸。首先采用有效区域理论计算了煤柱载荷;然后,由莫尔应力圆理论和库伦准则得出了含弱面的煤柱所能承受的极限载荷;最后得出了保留煤柱宽度的计算公式。研究表明:煤柱侧向压力对其强度和稳定性影响很大,当煤柱强度不足时,应采取调整煤柱位置、加大煤柱宽度和进行充填等措施来提高其稳定性。
In the dimension design of coal pillars in strip mining, presently, most of them are carried out by analyzing strength stability, without considering the effect of weak plane in coal pillar. Coal pillars with weak plane are often damaged, because the shear strength is not enough. Therefore, it is necessary to design the coal pillar dimensions according to the weak plane shear strength of the coal pillar. In the paper, the load of coal pillars is firstly calculated by effective area theory; then the limit support strength is deduced by Mohr' stress circle theory and Coulomb Criterion; At last, the calculation formula is worked out. The researches show that the lateral pressure has great effect on the strength and stability of the coal pillar, if the strength of the coal pillar is not enough, its stability can be improved by adjusting the position of the coal pillar, enlarging the width of the coal pillar and filling the gob.