围岩性质对采空区地基稳定性的影响

为了研究围岩性质对采空区建筑物地基稳定性的影响,通过数值模拟的方法分析单一岩层和复合岩层这两种模型.结果表明:在单一岩层中,随着上覆岩层硬度的增加,地表下沉及水平移动值会减小,大变形区(集中变形)范围都变小,破坏程度相应减小,但当上覆岩层为坚硬岩层时、其它条件相同时,上覆岩层硬度的增加,对采空区地基的稳定不利;在复合岩层中,上硬下软型的各地表移动和变形值都要比上软下硬型的小;但从塑性区状态图上看,在岩层内部上硬下软型的破坏程度更大,在软硬岩层界面更易产生顺层面离开的离层裂隙,因此上硬下软型的岩层组合对采空区地基的长期稳定不利.

Impact on foundation stability at goaf by bed rock characteristics

In order to understand the impact on foundation stability at goaf area by bed rock characteristics,this study investigates single rock stratum and compound rock strata through numerical simulation.The results show that in single stratum,the ground surface subsidence and the horizontal displacement evidently decrease,the range of large deformation and the degree of damage are reduced too with the increase of overlying stratum hardness.However,if the overlying stratum is hard rock and other conditions are the same,the foundation stability in goaf area will be reduced with the increase of overlying stratum hardness.While in compound rock strata,the surface movement and deformation with rigid upper layer and soft lower layer are smaller than that with rigid lower layer and soft upper layer.According to the state diagram of plastic zone,the more damage exists in the rock with rigid upper layer and soft lower layer.The soft and hard rock interface more likely has the bedding-slip separated fissures.Therefore,the rock strata with rigid upper layer and soft lower layer are unfavorable to the long-term foundation stability in goaf area.