煤柱失稳条件下浅埋房柱式采空区上覆地层变形特征  

Deformation characteristics of overlying strata in shallow-buried room-and-pillar mined-out area under instability of coal pillars

作　　者：刘亚明 谷天峰[3] 杨烜宇 王闫超 LIU Ya-ming;GU Tian-feng;YANG Xuan-yu;WANG Yan-chao(Shanxi Highway Safety Transportation Technology Co.,Ltd,Taiyuan 030800,China;Shanxi Transportation Technology Research&Development Co.,Ltd,Key Laboratory of Highway Construction and Maintenance 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]山西路安交通科技有限公司,太原030800 [2]山西省交通科技研发有限公司,黄土地区公路建设与养护技术交通行业重点实验室,太原030032 [3]西北大学地质学系,大陆动力学国家重点实验室,西安710069

出　　处：《兰州大学学报（自然科学版）》2024年第4期494-500,508,共8页Journal of Lanzhou University(Natural Sciences)

基　　金：国家自然科学基金项目(42041006,42027806,52278360);山西省科技厅项目(202203021222428)。

摘　　要：在煤柱失稳引起房柱式采空区顶板变形但未塌落的情况下,地表产生较大变形,威胁地面建筑物的安全.采用物理模拟和理论分析研究该条件下房柱式采空区上覆地层变形的发育机制,结果表明,房柱式采空区煤柱失稳后地表最大变形点与初期失稳煤柱位置、采空区顶板裂缝处三者在竖直方向上相对应;在采空区顶板变形但未塌落的情况下覆岩变形可划分为“条带状”、“梯形状”和“漏斗型”变形区域.松散层变形为“漏斗型”发育;采空区顶板发生断裂前可视为均布荷载作用下的固支梁模型.在煤柱失稳条件下,岩梁跨中下表面拉应力区产生竖向裂缝,并垂直向上扩展,煤柱的持续失稳会导致岩梁沿原裂缝薄弱面发生破坏,最终导致岩梁发生拉破断.基岩变形发展至交界面时,松散层逐渐发生滑移-拉裂-剪切破坏,最终形成“漏斗型”破坏形态.When the instability of a coal pillar causes the roof of a room-and-pillar mined-out area to deform but does not collapse,the surface undergoes a significant deformation,posing a threat to the safety of ground buildings and structures.The development mechanism of deformation in the overlying strata of the mined-out area under this condition was studied using physical simulation and theoretical analysis.The research showed that the maximum deformation point of the surface after the instability of the coal pillar in the mined-out area was corresponding to the position of the initial unstable coal pillar and the crack on the mined-out area roof in the vertical direction.When the roof of the mined-out area was deformed but did not collapse,the overlying rock deformation could be divided into three areas:the"strip shaped","ladder shaped",and"funnel shaped"deformation area.The loose layer deformed into a"funnel shaped"development.Before the roof of the mined-out area ruptured,it could be regarded as a fixed beam model under a uniform load.Under the condition of instability of the coal pillar,vertical cracks would occur in the tensile stress zone of the lower surface of the rock beam span and propagate vertically upwards.The continuous instability of the coal pillar would cause damage to the rock beam along the weak surface of the original crack,ultimately leading to a tensile fracture of the rock beam.When the deformation of the bedrock developed to the interface,the loose layer would gradually undergo a slip tension shear failure,ultimately forming a"funnel shaped"failure form.

关 键 词：房柱式 采空区 煤柱失稳 物理模型 

分 类 号：P642[天文地球—工程地质学]