摘要
在煤矿采空区地表进行城镇建设开发利用已成为国内矿业城市解决建设用地指标不足的有效途径。为了给城镇建设规划提供依据和保证拟建建筑的安全,首先必须对采空区场地进行地基稳定性评价,然后根据评价结果有针对性地采取建筑、结构、地基基础及采空区处理等治理措施。其中,小窑采空区往往因其开采面积小、顶板垮落不充分而成为悬顶区,悬顶区在地表建筑荷载作用下,有可能发生突发性的采空塌陷地质灾害,从而危及地表建筑及人员安全。极限平衡法是小窑采空区地基稳定性评价常用的方法之一,该方法通过建立采空区顶板压力、建筑基底压力、上覆岩层自重及岩体摩阻力四者之间的平衡方程而得到临界埋藏深度。但对于小窑采空区临界埋藏深度计算公式中基底压力p和埋深H参数概念的理解尚存在分歧,从而造成在评价工作中计算结果和评价结论的不唯一。针对该公式存在的问题进行了剖析,建立了与不同概念理解相对应的两种修正计算模型。研究对比分析后,建议采用以适用性更强的第二种修正计算模型为准,并明确了参数p和参数H的基本概念,即参数p的意义为建筑物基底平均压力,参数H的意义为自建筑物基底起算的采空区埋藏深度。在此基础上,又分别针对裸露型基岩场地和覆盖型基岩场地的情况,对第二种修正计算模型的采空区临界埋藏深度计算公式进行了改进和扩展,从而为更好地指导小窑采空区地基稳定性评价工作提供了参考。
The development and utilization of urban construction on the surface of coal mine goaf has become an effective way to solve the shortage of construction land index in domestic mining cities.In order to provide the basis for urban construction planning and ensure the safety of the proposed building,first of all,it is necessary to evaluate the foundation stability of the goaf site,and then according to the evaluation results,the treatment measures such as building,structure,foundation and goaf treatment can be taken.Among them,the small kiln goaf often becomes a suspended roof area due to its small mining area and insufficient roof caving.Under the action of surface building load,the suspended roof area may have sudden goaf collapse geological disasters,thus endangering the safety of surface buildings and personnel.Limit equilibrium method is one of the commonly used methods to evaluate the stability of foundation in small mine goaf.This method obtains the critical burial depth by establishing the equilibrium equation between roof pressure,building base pressure,self-weight of overlying strata and friction resistance of rock mass.However,there are still differences in the understanding of the concepts of base pressure p and burial depth H parameters in the calculation formula of critical burial depth of small kiln goaf,which leads to the non-uniqueness of calculation results and evaluation conclusions in the evaluation work.The problems existing in the formula are analyzed,and two modified calculation models corresponding to different concept understandings are established.After comparative analysis,it is suggested that the second modified calculation model with stronger applicability should be adopted,and the basic concepts of parameter p and H are clarified,that is,the meaning of parameter p is the average pressure of building basement,and the meaning of parameter H is the burial depth of goaf calculated from building basement.On this basis,the calculation formula of the critical burial depth of the goaf in the second modified calculation model is improved and extended for the bare and covered bedrock sites,so as to provide a reference for better guiding the evaluation of the foundation stability of the small kiln goaf.
作者
田迎斌
李科心
赵环帅
易四海
TIAN Yingbin;LI Kexin;ZHAO Huanshuai;YI Sihai(CCTEG Ecological Environment Technology Co.,Ltd.,Tianjin 300450,China;China University of Mining&Technology-Beijing,Beijing 100083,China;School of Safety Engineering,North China Institute of Science&Technology,Langfang 065201,China)
出处
《中国矿业》
北大核心
2024年第11期113-120,共8页
China Mining Magazine
基金
国家面上基金项目资助(编号:52274165)
中国煤炭科工集团有限公司科技创新创业资金项目资助(编号:2022-2-ZD004)
中煤科工生态环境科技有限公司科技创新基金项目资助(编号:0206KGST0020,0206KGST0027)。
关键词
极限平衡法
小窑采空区
临界埋藏深度
修正计算模型
地基稳定性评价
limit equilibrium method
small kiln goaf
critical burial depth
modified calculation model
evaluation of the foundation stability