【摘要】 某采石场开采形成了浅埋采空区群,且空区群上覆有一条县级公路。为确保上覆公路和采石场的安全运行,对采空区和上覆公路的稳定性进行了综合分析。首先,对采空区现状、工程地质和水文地质进行了调查;通过开展现场点荷载试验和室内岩石力学试验,获得了围岩的基本力学参数;随后,采用Heok-Brown准则及其强度参数的估计法,将岩石力学参数转化为岩体力学参数;接着,基于转换的力学参数,利用FLAC3D数值模拟软件对采空区和上覆公路进行了模拟分析,并探讨了采空区及行车荷载对上覆公路的影响。研究结果表明:采空区处于稳定状态,对上覆公路影响较小;公路总体稳定,但公路与采空区的相对空间位置引起的地表不均匀沉降带来的局部离层对于公路有一定的危害。根据分析结果,建议充填4#采空区以降低采空区暴露面积,减少采空区分布的不均匀性以减少对公路离层区的影响,对于公路的局部离层区可采取注浆加固。更多还原

【Abstract】 After more than ten years of underground mining in a quarry in Liuyang City,a gob group was formed by four irregular goafs,and the gobs were close to the surface with a running county-level Jiuxi highway. In order to develop the next-stage mining plan and ensure the safe operation of the above-mentioned roads and the quarry,it is necessary to comprehensively analyze and judge the stability of the goaf group and the overlying road. Field surveys about occurrence condition of goafs,hydrogeology survey as well as engineering geometry survey were performed. On-site point sample loading experiments and indoor rock mechanics experiments were made and basic mechanical parameters of surrounding rock were obtained and then the chart of the discrete strength parameters of the rock was used to analysis the quality of rock mass.After that,the required strength parameters for numerical analysis were calculated out with the method of HoekBrown principle as well as some amendments of related strength parameters. Then,numerical model about shallow buried connected goaf groups of the quarry formed after mining as well as highway on topsoil over the goaf group was built to evaluate the stability of goafs and highway so as to bring forward corresponding measures.After the initial geo-stress simulation and the formation of the goafs,in order to explore the impact of the driving load on the goaf,the driving load is applied to the road surface in the form of normal pressure,and then calculated to balance. Comprehensive evaluations on stability of goafs show that goafs are basically in stable condition and the goafs have little influence on overlying highway. The results also indicate that the highway is generally stable with partial separation of layers.Due to the spatial distribution characteristics of the goafs,the subsidence curvature caused by the uneven settlement and the local separation of road layers are harmful to the highway.The distribution of separation zone presents the characteristics of overall dispersion and local concentration,that is,unevenly distributed local strip-shaped separation zone. To ensure the safety of goaf and healthy running of highway,disposal measures for goafs and the road were proposed. Overall,the relative spatial position of the highway and the goafs and the surface topography of the surface play a major role in controlling the damage form of the highway.To ensure the safety of the road and avoid the activation of the goafs.Finally,it is recommended to backfill the 4# goaf to reduce the non-uniformity of spatial distribution and reinforce the separation part of the road by local grouting.更多还原