基于岩块间应力的传递和演化会改变采空区垮落岩体的密实程度，进而影响垮落岩体空隙的分布，最终影响采空区瓦斯的流动特性，为了解采空区瓦斯运移通道，获得控制瓦斯流动的理论依据，基于离散单元法，采用Hertz-Mindlin接触模型，通过自编程序，分别模拟了直径为0.6、0.8、1.0 m的岩块组成的垮落岩体在轴向应变为0、0.05、0.10、0.15、0.20和0.25%下的压实过程，研究了采空区垮落岩体内应力是如何通过改变岩块间的接触网络来影响垮落岩体空隙率的分布。研究结果表明：垮落岩体内应力通过岩块间的接触网络进行传递，随轴向应变增大，垮落岩体内应力逐渐增大，传递应力的接触网络也越密集；压缩过程中，外部载荷无法从垮落岩体顶部的受力端均匀地传递到下部，使垮落岩体上部岩块受力大于下部，且随轴向应变增大，岩块间接触力较大的区域自垮落岩体上部向下不断扩展；由于垮落岩体下部岩块受外力扰动小，使垮落岩体下部岩块间的接触网络较疏松，配位数较小。垮落岩体自下向上空隙率先急剧降低，随后缓慢下降。其中自然堆积状况下，垮落岩体因自重所产生的应力较小，不同层位岩块的配位数相差较小，使垮落岩体底部空隙率仅为上部空隙率的1.1倍。而在压实状况下，垮落岩体不同层位岩块受力相差较大，垮落岩体底部岩块的配位数远小于垮落岩体上部，导致垮落岩体底部空隙率是上部空隙率的1.4倍。

The transfer and evolution of stress between rock blocks will change the compactness of crushed rock mass in the gob,and then affect the void distributions of crushed rock mass,and finally change the flow of gas in the gob.In this paper,a discrete element method was used,along with the Hertz-Mindl in contact model and self-programming.The compaction processes of crushed rock mass composed of rock blocks with diameters of 0.6 0.8 and 1.0 m were simulated,with axial strains set at 0、0.05、0.10、0.15、0.20,and 0.25%,respectively.The goal of this study was to study how the internal stress of crushed rock mass in the gob affected the void distribution of crushed rock mass by changing the contact network between the rock blocks.The results showed that the stress in crushed rock mass was transmitted through the contact network between the rock blocks,and as the axial strains increased,the stress in the crushed rock mass increased gradually,and the contact network that transmitted the stress became denser.During the compression process,the external load could not be uniformly transmitted from the top of the crushed rock mass to the lower part,so that the stress in upper part of the crashed rock mass was significantly higher than the lower part.As the axial strains increased,the range with large contact force between the rock blocks gradually expanded from the upper part of the rock mass to the lower part.Because the rock blocks in the lower part of the crushed rock mass wasless interfered by the external force,the contact network between the rock blocks in the lower part of the crushed rock mass was looser,and the coordination number of the rock blocks in the lower part of the crushed rock mass was small.The void rate of the crushed rock mass decreased sharply from bottom to top,and then slowly decreased.Under the natural accumulation condition,the stress generated by the self-weight of crushed rock mass was small,and the coordination number of rock blocks in different layers was relatively small,so that the voidage at the bottom of the crushed rock mass was only 1.1 times that in the upper of crushed rock mass.However,under compaction conditions,the stress in different layers of the crushed rock mass had a large difference,and the coordination number of the rock blocks at the bottom of crushed rock mass was much smaller than that of the upper part,so that the voidage at the bottom of the crushed rock mass was 1.4 times that in the upper of crushed rock mass.