浅埋特厚煤层下向分层膏体充填开采覆岩变形控制机理  

Shallow and extra-thick coal seam miningin the bottom layer paste filling overburden deformation control mechanism

作　　者：孙希奎 范建国 常庆粮[2,3] SUN Xikui;FAN Jianguo;CHANG Qingliang(Shandong Energy Group Co.,Ltd.,Jinan 250101,China;School of Mines,China University of Mining and Technology,Xuzhou 221116,China;Key Laboratory of Deep Coal Resources Mining,Ministry of Education,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]山东能源集团有限公司,山东济南250101 [2]中国矿业大学矿业工程学院,江苏徐州221116 [3]中国矿业大学深部煤炭资源开采教育部重点实验室,江苏徐州221116

出　　处：《绿色矿山》2024年第3期221-233,共13页Journal of green mine

基　　金：国家自然科学基金面上资助项目(52174130)。

摘　　要：浅埋煤层因其顶板结构特征、矿压显现特征的独特性而导致其岩层控制机理的差异性。针对浅埋特厚煤层分层膏体充填开采沉陷控制问题,下分层开采时顶分层充填体作为假顶,因充填体结构致密,且无节理裂隙,探究浅埋煤层分层充填体假顶条件下的覆岩控制机理意义重大。采用理论分析、数值模拟与工程实测等综合研究方法,构建了膏体充填开采直接顶力学模型,解析了直接顶断裂失稳临界条件,提出了浅埋煤层岩层控制的核心要素为充填率,揭示了浅埋特厚煤层分层膏体充填开采覆岩变形控制机理,建立了浅埋特厚煤层分层膏体充填开采数值计算模型,探究了不同充填率下覆岩及地表移动变形特征,实测了充填体受力特征及地表移动变形量。研究表明:顶板岩梁极限跨距为17.9 m,与之相对应的挠度为0.54 m,上、下分层采高分别为4.65 m与3.65 m,计算得上分层充填率不低于88%,总体充填率不低于93%,可保证顶板不会断裂失稳;随着充填率提高,覆岩应力集中系数与变形量不断降低,充填体承载作用逐渐增强,地表移动变形量逐渐减小,当上、下分层的整体充填率达到98%,地表移动变形量均可满足建(构)筑物保护要求;上分层充填开采后,充填体所受应力逐渐增加并稳定于2.3 MPa左右,实测地表最大下沉57 mm,最大倾斜值0.82 mm/m,最大曲率值0.03 mm/m^(2),地表移动变形量均在Ⅰ级设防指标范围内,充填效果良好。Due to the unique characteristics of its roof structure and mining pressure manifestation,shallow buried coal seams have different rock control mechanisms.In response to the problem of subsidence control in shallow buried thick coal seam layered paste filling mining,the top layered filling material is used as a false roof during lower layered mining.Due to the dense structure and absence of joints and fissures in the filling material,exploring the overburden control mechanism under the false roof conditions of shallow buried coal seam layered filling material is of great significance.This article adopts comprehensive research methods such as theoretical analysis,numerical simulation,and engineering measurement to construct a direct roof mechanics model for paste filling mining.The critical conditions for direct roof fracture instability are analyzed,and the core element for controlling shallow buried coal seam rock layers is proposed as the filling rate.The deformation control mechanism of overlying rock in shallow buried thick coal seam layered paste filling mining is revealed,and a numerical calculation model for shallow buried thick coal seam layered paste filling mining is established.The deformation characteristics of overlying rock and surface movement under different filling rates are explored,and the stress characteristics and surface movement deformation of the filling body are measured.Research has shown that the ultimate span of the roof rock beam is 17.9 m,with a corresponding deflection of 0.54 m.The mining heights of the upper and lower layers are 4.65 m and 3.65 m respectively.The calculated filling rate of the upper layer is not less than 88%,and the overall filling rate is not less than 93%,which can ensure that the roof will not fracture or become unstable;As the filling rate increases,the stress concentration coefficient and deformation of the overlying rock continuously decrease,the bearing capacity of the filling body gradually increases,and the surface movement deformation gradually decrease

关 键 词：浅埋特厚煤层 膏体充填 分层开采 覆岩移动变形 

分 类 号：TD325[矿业工程—矿井建设]