采动覆岩与地表下沉关系模型及离层量估算方法  

Relationships between mining overburden rock and surface subidence and its application to estimate bed separation

作　　者：崔希民[1] 高宇 李培现[1] 李梓豪 张文豪 彭小沾 康新亮 CUI Ximin;GAO Yu;LI Peixian;LI Zihao;ZHANG Wenhao;PENG Xiaozhan;KANG Xinliang(College of Geoscience and Surveying Engineering,China Unwersity of Mining and Technology-Beijing,Beijing 100083,China;Technical Center Xishan Coal Electricity Group Co.,Ltd.,Taiyuan 030053,China;Geology Department,Xishan Coal Electricity Group Co.,Ltd.,Taiyuan 030053,China)

机构地区：[1]中国矿业大学(北京)地球科学与测绘工程学院,北京100083 [2]西山煤电(集团)有限责任公司技术中心,山西太原030053 [3]西山煤电(集团)有限责任公司地质处,山西太原030053

出　　处：《煤炭学报》2023年第1期74-82,共9页Journal of China Coal Society

基　　金：河北省自然科学基金生态智慧矿山联合基金资助项目(E2020402086);国家自然科学基金资助项目(52274169);中国矿业大学(北京)大学生创新训练基金资助项目(202202026)。

摘　　要：地下开采可能导致地表沉陷、基础设施损毁、土地破坏或地面积水等,进而诱发生态环境恶化。而采空区固体充填和覆岩离层注浆是控制岩层移动,减小采动损害的有效技术手段。传统的覆岩离层注浆往往采用关键层理论、数值模拟、相似材料模型实验和理论分析手段,因涉及的物理力学参数多、边界条件限制等,计算过程复杂,仅能给出离层层位,难以定量确定离层量。开采沉陷研究表明,采动覆岩与地表移动方向指向采空中心,移动边界可以简化为线性边界,基于下沉盆地主断面上地表下沉与任一覆岩下沉的面积相等和煤系地层的层状特征,构建了采动覆岩与地表下沉的关系模型,较好地反映了覆岩与地表下沉随边界角、工作面宽度、开采深度的发展演化规律。采动覆岩与地表下沉比值随埋藏深度增加而增大,反映了采动下沉效应从顶板向覆岩、地表的传递规律;随着宽深比的增加,同一层位岩层下沉与地表下沉比值减小,地表下沉增大;当边界角减小时,地表下沉范围增大,地表下沉值减小。结合钻孔揭示的覆岩结构与组合,可以逐层计算上覆岩层和地表的下沉值,利用两相邻岩层下沉的非一致性,可以确定各岩层间的离层量,通过计算导水裂隙带高度,剔除导水裂隙带内无法形成封闭充填空间的无效离层,进而优选确定出适用于覆岩离层注浆的最大离层及层位,为覆岩离层注浆减沉设计提供了简单、便捷的离层识别方法和离层量定量计算方法。Underground mining may result in surface subsidence,infrastructure damage,land degradation and surface water accumulation,and cause the ecological deterioration.In order to control the surface and overburden rock strata movement and reduce the mining damage,the solid filling in goaf and overburden grout injection to bed separation are selected as useful techniques.The location of bed separation can be given by the traditional methods such as key strata theory,numerical simulation,similar tmaterial experiment and theoretical analysis.However,it is difficult to determine the quantitative value of bed separation because of its complicated calculation process,multiple physical and mechanical parameters and the effect of boundary conditions.The research results of mining subsidence demonstrate that the overburden and surface move towards to the goaf center along the ray projection,the subsidence boundary of overburden and surface can be simplified as straight line according to the synthetic limit angle and the surface subsidence area equals to any overburden strata subsidence area.Based on these research consensus about the characteristics of coal measure strata,the relationship model between mining overburden strata and surface subsidence have been established,which well reveals the evolution of overburden and surface subsidence with the synthetic limit angle,width of working face and mining depth.The ratio of mining overburden strata and surface subsidence increases with the increasing of burial depth for overburden strata,it reflects the transfer law of mining subsidence effect from roof to overburden and surface.When the width-depth ratio increases,the ratio of overburden-surface mining subsidence decreases and the surface subsidence increases.If the synthetic limit angle decreases,the range of surface subsidence increases and the corresponding surface subsidence decreases.The overburden rock strata and surface subsidence can be calculated layer by layer according to the actual strata thickness by borehole.For the

关 键 词：岩层厚度 离层 地表下沉 覆岩注浆 等效下沉 

分 类 号：TD325[矿业工程—矿井建设]