长壁老采空区残余沉降计算方法研究

Research on calculating method of residual subsidence of longwall goaf

在深入分析老采空区残余沉降机理的基础上,认为采动破裂岩体空隙是老采空区残余沉降的主要诱因,采用国内外得到的有关破裂岩体应力应变关系及采动破裂岩体高度计算方法,建立了老采空区残余下沉系数计算方法,分析了残余下沉系数与覆岩岩性、开采厚度、开采深度及建筑物载荷的关系。研究表明:①当开采厚度相同时,开采深度越小,残余下沉系数越大,说明后期可能产生的地表残余沉降越大;当开采深度相同时,开采厚度越大,残余下沉系数越小;②在建筑载荷与原岩应力比相同情况下,开采深度越小,下沉系数增加量越大,对老采空区的影响越大。

On the basis of analyzing the mechanism of residual subsidence of old goaf,the model of calculating residual subsidence of gobs was deduced by combining the results of ruptured rock mass.Meanwhile the relationship were analyzed between the coefficient of residual subsidence and the characteristic of overburden strata,mining thickness,mining depth and building load.The research results show that while mining thickness is same,the shallower mining depth is,the larger coefficient of residual subsidence is,and there is larger surface residual subsidence in the future;While mining depth is same,the larger mining thickness is,the smaller coefficient of residual subsidence is;When the propotion of constuction loads to overburden stress is the same,the smaller the mining depth is,the larger the augmenter of subsidence coefficient is,and has more effect old goafs.