文献类型：期刊文献

中文题名：采动影响下深埋软岩巷道变形特征与控制因素分析

英文题名：Deformation characteristics and control factors of the surrounding rock in the deep buried soft rock roadway under the influence of mining

作者：余伟健 李可 张靖 韩森 廖泽 张宗堂

第一作者：余伟健

机构：[1]湖南科技大学资源环境与安全工程学院,湖南湘潭411201;[2]湖南科技大学煤矿安全开采技术湖南省重点实验室,湖南湘潭411201;[3]贵州理工学院矿业工程学院,贵州贵阳550003;[4]贵州耀辉矿业发展有限公司,贵州遵义551400

第一机构：湖南科技大学资源环境与安全工程学院,湖南湘潭411201

年份：2020

卷号：48

期号：1

起止页码：125-135

中文期刊名：煤炭科学技术

外文期刊名：Coal Science and Technology

收录：CSTPCD;;北大核心:【北大核心2017】；CSCD:【CSCD2019_2020】；

基金：国家自然科学基金资助项目(51974117)

语种：中文

中文关键词：采动影响;力学模型;软岩巷道;不均衡变形;控制因素

外文关键词：mining effect;mechanical model;soft rock roadway;unbalanced deformation;main controlling factors

摘要：针对深埋软岩巷道虽布置在回采破坏范围之外,在回采反复扰动之下仍发生大变形的现象,采用现场调研、巷道围岩应力场分析和数值模拟试验等方法进行研究。在前人研究的基础上,建立了巷道开挖应力场和煤层回采应力场的耦合应力计算模型,代入相关数据后,发现邻近的C5煤层采空后引起的应力升高或降低幅度均在15%以下,认为单纯的应力改变一般不会造成支护整体失效或巷道大变形,反复扰动后围岩力学强度降低,致使其由弹塑性变形过渡到松动变形是关键原因。采用FLAC3D软件模拟了煤系倒转的情况及附近岩层中的巷道前期围岩变形可控、后期在回采反复扰动下应力分布特征与不均衡变形的过程。分析了持续性底鼓的原因及喷层、锚杆与锚索失效的原因。根据分析,提出了巷道的一次支护最佳状态和二次支护最佳时机,认为开挖后应优先喷浆允许巷道在弹塑性范围内充分变形以释放围岩应力后再进行强力支护,以达到一次支护最佳状态;认为二次支护的最佳时机是上区段采空之后下区段回采之前;认为施工工序和喷层厚度小导致喷层刚度与围岩协调作用不足是其失效的关键因素;认为需进行底板支护,以形成完整的支护结构,避免应力从底板释放是控制底鼓的关键因素;认为支护时机、锚杆长度和安装质量是锚杆与锚索失效的关键因素。
In view of the phenomenon that deep buried soft rock roadway is arranged outside the range of mining but large deformation still occurs under repeated mining disturbance,the field investigation,stress field analysis and numerical simulation tests are adopted. On the basis of previous studies,a coupled stress calculation model for the stress field of roadway excavation and the stress field of coal seam mining was established. After substituting the data of the research object,it was found that the stress increase or decrease caused by the gob of the adjacent C5 coal seam was below 15%. It is believed that the simple change of stress will generally not cause the overall failure of the support or the large deformation of the roadway,and the mechanical strength of the surrounding rock will be reduced after repeated disturbances,causing the transition from elastoplastic deformation to loose deformation. FLAC3D was used to simulate the inversion of coal-measure strata and the process of controlled deformation of surrounding rock in the early stage of roadway and uneven deformation in the later stage under repeated disturbance of mining.The causes of continuous floor heave and the failure of spray coating,bolt and anchor cable are analyzed. According to the analysis,the optimal state of primary support and the optimal time for the secondary support of the research object are proposed. It is believed that the shotcrete should be preferentially sprayed after excavation to allow the roadway to fully deform in the elastoplastic range to release the surrounding rock stress,and then strong support should be carried out to achieve the optimal state of primary support,and the best time for secondary support is considered to be after the upper section is mined out and before the lower section is mined. The key factor of the failure is the lack of coordination between the stiffness of the jetting layer and surrounding rock caused by the small construction process and the thickness of the jetting layer. It is considered that the key factor to control floor heave is to support the floor to form a complete support structure and avoid the release of stress from the floor. It is also considered that the timing of the support,the bolt length of the anchor rod and the installation quality are the key factors of bolt and cable failure.