矸石充填沿空留巷巷旁支护体力学行为研究

Goaf filling materials control the overlying strata movement and changed the bearing structure of gob-side entry retaining with gangue backfilling mining. Compared to gob-side entry retaining of traditional caving method, bearing mechanism of roadside support has been changed. It is necessary to analyze the bearing mechanism of roadway support with gob-side entry retaining with gangue backfilling mining. The project focuses on mechanical behavior of roadside support. Firstly, conduct a research on the roadside filling material’s ompaction deformation and sound emission law under the condition of one side restriction through self-developed experiment platform, Reveal the mechanical response mechanism of material strength and damage evolution. Secondly, ascertain the overlying strata-structure characteristic and in gob-side entry retaining with gangue backfilling mining. The section non-uniform elastic foundation mechanical model is established to study the reactive relationship between roof deformation characteristic and mechanical parameter of roadside support. And explain the mechanism of roadside support cooperation with backfilling material in gob. Finally, “discrete-continuous” coupling mathematical modeling is established to analyzes the roadside support’s bearing characteristic and time-variant effect affected by rheology of backfilling material in gob and to give the calculation method of time-varying safety factor and long-term strength of roadside support. Based on the instability mechanism of roadside support through the lateral stability mechanical model and propose design method of side support in gob-side entry retaining, the research findings will provide theoretical support for gob-side entry retaining with gangue backfilling minging.

矸石充填采空区密实充填体抑制了覆岩移动，改变了沿空留巷围岩承载结构。相比于传统垮落法开采，矸石充填沿空留巷巷旁支护体承载特性发生了本质改变，其承载机理亟待深入分析。本项目拟采用实验室测试、理论分析、数值模拟等综合手段对巷旁支护体力学行为展开研究。首先，借助自主搭建的压实与声发射测试平台，研究单侧限约束下胶结巷旁充填材料压缩变形与声发射规律，揭示材料强度与损伤演化力学响应机制；其次，探明沿空巷道侧向覆岩结构特征，建立顶板分段非均匀弹性地基力学模型，分析顶板变形与力学参数的互馈作用，揭示巷旁支护体联合采空区充填体协同作用机制。最后，设计“离散-连续”介质耦合数值分析模型，分析巷旁支护体承载特性及其时变效应影响特征，构建时变安全系数并给出长期强度计算方法。建立巷旁支护体侧向稳定性力学模型，揭示巷旁支护体失稳机理，提出巷旁支护设计方法。项目研究成果将为矸石充填沿空留巷技术提供理论支撑。

矸石充填采空区充填体承载了大部分覆岩载荷，为沿空留巷提供了有利实施条件，但采空区充填体同样改变了采场覆岩结构，致使巷旁支护体承载机制及其力学行与传统垮落法开采差异显著。项目采用实验室测试、物理模拟、数值模拟和力学分析等综合研究手段，对矸石充填沿空留巷巷旁支护体力学行为展开全面研究。通过实验室测试分析不同配合比巷旁充填材料压实特性，优化了巷旁充填材料配合比；采用颗粒流数值模拟软件，通过三维扫描重构矸石颗粒并建立数值模型，分析了巷旁支护体不同受力阶段的压实特性，并研究了颗粒级配、加载速率对破碎矸石压实特性和侧压系数的影响规律；采用物理相似模拟实验分析了不同充实率条件下矸石充填沿空留巷覆岩结构特征与演化规律，建立了固体密实充填采煤沿空留巷力学模型，运用弹性地基梁理论，分析了基本顶下沉量随巷旁支护体的宽度和强度的变化的关系。揭示巷旁支护体协同采空区矸石充填体控制覆岩变形机理，阐明矸石充填沿空留巷巷旁支护体作用机制。构建数值模型，研究不同埋深、工作面充实率、巷旁充填体宽度和强度条件下沿空留巷围岩应力演化；研究不同因素对固体充填采煤沿空留巷巷旁支护体侧向变形的影响规律，在分析固体充填采煤沿空留巷巷旁支护体变形特征的基础上，基于库仑土压力理论的平面滑裂面假设，建立了沿空留巷巷旁支护体力学模型, 分析探讨支护体墙背法线反力、矸石滑裂面与竖直线夹角与各影响因素间的作用关系，揭示了矸石充填沿空留巷巷旁支护体失稳机理，并提出巷旁支护设计方法。项目研究成果将为矸石充填沿空留巷技术提供理论支撑，丰富充填采煤与沿空留巷矿压控制理论。.依托项目发表学术论文10篇，出版著作1本，授权发明专利申请专利2项，申请专利4项，转化专利1项，获江苏省科学技术步三等奖奖1项。