将地下空区顶板视为梁模型,采用结构稳定理论,建立水平应力与地下空区项板安全厚度之间的关系;以裂隙张量为基础,将岩体中的裂隙看作初始损伤,对含随机分布裂隙的顶板岩体进行分析,推求裂隙岩体的等效变形模量和等效泊松比,从而建立地下空区项板厚度与岩体裂隙密度之间的关系,并探讨水平应力与岩体裂隙密度对地下空区顶板厚度的影响。研究结果表明:地下空区顶板厚度与水平应力及岩体裂隙密度具有较大的相关性,最小安全厚度随着水平应力的增大而增大,当水平应力由0MPa增加到15MPa时,对安全厚度的影响较大;当水平应力大于15MPa时,随着水平应力的增大,安全厚度的增加幅度较小;最小安全厚度随着岩体裂隙密度的增大而增大,安全厚度与裂隙密度近似呈直线关系。
The roof of underground vacant area was taken as a beam model, the relationship between safety height and horizontal stress was built using structure stability theory, and the behavior of rock mass containing a random distribution cracks was discussed regarding cracks as initial damage on the basis of crack tensor. The equivalent modulus and the equivalent Poisson's ratio were derived, and the relationship between safety height and rock crack density was built, the influence of horizontal stress and rock crack density on the height of roof were discussed. The results show that the height of roof is related to horizontal stress and rock crack density, and the height of roof increases with the increase of horizontal stress and rock crack density. The influence of horizontal stress is bigger when the horizontal stress increases from 0 MPa to 15 MPa than that when horizontal stress is bigger than 15 MPa. The relationship between the roof height and crack density is approximately linear.