基于物理模拟试验的房柱式采空区变形特征研究  

Study on deformation characteristics of room-and-pillar mined-out area based on physical simulation test

作　　者：刘亚明 谷天峰[3] 王闫超 杨烜宇 LIU Yaming;GU Tianfeng;WANG Yanchao;YANG Xuanyu(Shanxi Transportation Technology Research&Development Co.,Ltd,Taiyuan 030032,China;Key Laboratory of Highway Construction andMaintenance Technology in Loess Region,Taiyuan 030032,China;State Key Laboratory of Continental Dynamics,Department of Geology,Northwest University,Xi’an 710069,China)

机构地区：[1]山西省交通科技研发有限公司,山西太原030032 [2]黄土地区公路建设与养护技术交通行业重点实验室,山西太原030032 [3]西北大学地质学系大陆动力学国家重点实验室,陕西西安710069

出　　处：《煤炭科学技术》2024年第S01期30-36,共7页Coal Science and Technology

基　　金：国家自然科学基金资助项目(42027806,52278360);山西省科技厅资助项目(202203021222428)。

摘　　要：房柱式采空区具有采出率较小、留设煤柱较大的特点,其覆岩移动规律及地表变形规律与长壁式采空区差别较大,在煤柱失效情况下,地表会产生较大变形,威胁地面建构筑物的安全。为研究浅埋缓倾房柱式采空区覆岩和松散层的变形发育机制,基于PIV图像处理技术和模块化组装思路,在室内建立物理模型开展物理模拟试验,反演了房柱式采空区覆岩和松散层的变形发育过程,分析了房柱式开采和煤柱失稳条件下覆岩和松散层的变形机制。研究结果表明:①房柱式开采条件下,浅埋缓倾采空区覆岩变形可划分为3个区域:“条带状”变形区域、“梯形状”变形区域和“倒漏斗型”变形区域。松散层中的变形呈“梯形状”发育。②煤柱失稳条件下,覆岩变形规律保持不变,松散层变形特征由“梯形状”发育为“漏斗型”,且随着失稳煤柱的增加,松散层变形增大,“漏斗型”变形区域由中心向两端逐渐扩展。③房柱式开采结束后,采空区顶板受力可简化为承受均布荷载的简支梁,在煤柱持续失稳的情况下,覆岩和松散层的静载将导致采空区顶板达到极限平衡状态,顶板破坏模式为拉破断,在拉应力作用下产生裂缝,但顶板并未完全断裂,采空区顶板形成一种带裂缝的悬臂梁结构。浅埋缓倾房柱式采空区煤柱失稳对地表变形影响剧烈,松散层变形与覆岩变形基本处于同一量级。The room-and-pillar mined-out area has the characteristics of small recovery rate and large coal pillar,and its overburden move-ment law and surface deformation law are quite different from those of long-wall mined-out area.In the case of coal pillar failure,the sur-face will produce large deformation,threatening the safety of surface structures.In order to study the deformation and development mech-anism of overlying rock and unconsolidated formation in shallow and gently tilted room-and-pillar mined-out area,based on PIV image processing technology and modular assembly idea,a physical model was established in the laboratory to carry out physical simulation ex-periments,inversion of the deformation and development process of overlying rock and unconsolidated formation in room-and-pillar mined-out area,and analysis of the deformation mechanism of overlying rock and unconsolidated formation under the condition of room-and-pillar mining and coal pillar instability.The research results show that:①the overburden deformation of shallow buried and gently mined goaf can be divided into three areas:“banded”deformation area,“trapezoidal”deformation area and“inverted funnel”deformation area.The deformation in the unconsolidated formation is“trapezoidal”.②Under the instability condition of coal pillar,the overburden de-formation law remains unchanged,and the deformation characteristics of unconsolidated formation develop from“trapezoidal”to“funnel”.With the increase of unstable coal pillar,the deformation of unconsolidated formation increases,and the“funnel”deformation area gradually expands from the center to both ends.③After the end of room-and-pillar mining,the stress of the goaf roof can be simpli-fied to simply supported beams bearing uniform load.In the case of continuous instability of coal pillar,the static load of overlying rock and unconsolidated formation will lead to the goaf roof reaching the ultimate equilibrium state.The failure mode of the roof is tensile breaking,and cracks

关 键 词：房柱式 采空区 覆岩移动 松散层 地表变形 

分 类 号：P642[天文地球—工程地质学]