巷道垮落体中再造应急救援通道支护机理研究

The Underground roadway collapses, and it makes the personnel not escaping from the disaster spot. Interaction principle between falling body and the support becomes a key problem, when the rescue roadway is excavated in the falling body. The project adopts the research methods of field investigation, theoretical analysis, similarity simulation experiment and field application. It gets surrounding rock properties, disaster causes and falling body characteristics of the original roadway. The falling body is divided into three types including large granularity, medium granularity and small granularity, according to the rescue roadway size. It completes the determination of the mechanical properties of three types of falling body, including the strength, the viscosity and the repose angles. It establishes mathematical model and constitutive relation of the large granularity falling body deformation .It establishes mathematical models and constitutive relations of falling body movement, including medium granularity and the small granularity which is less than liquid limit. It establishes mathematical model and constitutive relation of the falling body small granularity which is more than liquid limit flow. The mathematical models are solved with the methods of finite element of secondary development and the discrete element .It simulates the mechanical properties of the large granularity falling body deformation, medium granularity movement, the small granularity which is less than liquid limit movement, and small granularity which is more than liquid limit flow, using the homemade simulation test bed. It optimizes mathematical model on base of the analysis experiment result and the theory study result. It tests and analyses interaction of excavating and supporting rescue roadway, using the homemade supporting equipment. It researches on deformation, flow, movement of the falling body, and the interaction principle among three types of the falling body, through comparing the test result with the theory analysis result. It reveals support mechanism of the rescue roadway which is excavated in the falling body, and provides a theoretical guidance for excavating the rescue roadway.

井下巷道垮塌，阻断了人员逃离，垮落体与支护体相互作用机理成为在垮塌体中再造救援通道关键问题。项目采用现场考察、理论分析、相似模拟实验和现场应用相结合研究方法，研究原巷道围岩性质、致灾原因和垮落体特征；对照再造通道尺度，将垮落体分为大粒度、中粒度和小粒度三种类型。测定三种垮落体强度、黏度、自然安息角等力学特性；分别建立大粒度变形、中粒度和小于液限小粒度垮落体运动及大于液限小粒度垮落体流动的本构关系和数学模型，用二次开发有限元、离散元程序求解。用自制模拟试验台，分别模拟大粒度变形、中粒度和小于液限小粒度移动以及大于液限小粒度垮落体流动特性，对照分析实验结果与理论分析，优化数学模型。采用自制支架，对再造通道掘进、支护及其相互作用进行测试分析，将测试结果与理论分析对比，研究三种垮落体变形、运动及流动与支护体间相互作用原理。揭示垮落体内再造应急救援通道支护机理，为应急救援通道开挖提供理论指导。

以黑龙江省四大矿区所属煤矿发生过垮塌的巷道为基础，研究煤矿发生灾害时巷道垮落体中再造应急救援通道支护机理。. 用蒙特卡洛法在二维的平面上拟化成不同类型的裂隙模型，并借助相对应的数值分析软件探讨并观察裂隙角度对巷道围岩的变形的影响。分析了不同构造型冲击地压作用下巷道破坏可能产生的垮落体特征，认为对于有大裂纹围岩，坍塌时在巷道破坏初期失稳模式与无裂隙巷道的破坏模式大体相同，随着结构面角度与最大荷载应力一致时破坏的最为彻底，形成的破碎散体也块度较小。. 对堆积体内块体颗接触结构进行了研究，通过对堆积体内颗粒堆中沉降变形分析得出了在堆积体内颗粒之间是存在着拱结构与“自组织”现象，导致了各球体颗粒之间内部摩擦、咬合力也逐渐变大，形成拱结构。. 对煤散体的物理力学特性进行了相似模拟试验研究，通过对模型的试验分析，得到了煤矿井下垮落煤散体的剪切力、内摩擦角等基本物理力学性质。得到结果是：随着剪切速率的增加，煤散体的抗剪强度表现出先增大、后减小的趋势，内摩擦角也呈现出先增大、后减小的趋势，但黏聚力却保持增长。剪切速率超过0.15mm/s后，黏聚力的增长率较缓，基本保持稳定；测试了煤散体对侧壁的侧向压应力系数，认为侧向压应力系数不仅与散体的侧向压应力和垂直主应力有关，还要考虑与侧壁的摩擦阻力影响。同样高度，不同宽度的煤散体，随着宽度的增加，其侧向压应力系数增大；通过相似模拟研究了不同救援通道位置的支护体受力情况。认为在实际选择救援通道开挖的位置时，应优先考虑靠近稳定的围岩帮进行救援通道的开挖。. 对在破碎堆积散体内无支护开挖特性进行了离散元模拟研究，分析了堆积体开挖特性。对不同类型散体进行开挖，获得开挖后堆积体的赋存形态、颗粒的移动轨迹和滑移面等特性；对散体在巷道内赋存状态进行受力分析，获得堆积体的侧压力系数、滑移面倾角等性质。. 本研究成果可为应急救援通道开挖提供理论指导。