沿空留巷巷旁支护大砌体结构的力学特性研究

发布时间：2018-03-27 16:21

本文选题：沿空留巷　切入点：巷旁支护　出处：《西安科技大学》2017年硕士论文

【摘要】：沿空留巷巷旁支护采取大砌体混凝土构造,克服了现有巷旁支护体不能同时具有结构早强、无粉尘、劳动强度小以及快速机械化施工的问题。为此研究大砌体结构作为巷旁支护体的力学特征要求,并在此研究基础上进行了工业试验。首先从沿空留巷上覆岩层的垮落活动规律入手,分析得出被动垮落比主动垮落难控制,应及时沿支护体的外侧切断放顶来减小上覆岩层垮落时的压力。通过对上覆岩层的运动规律与巷旁支护体的互相作用进行分析,明确了沿空留巷巷旁支护体的力学性能是承载力和变形配合作用下的函数关系。通过对巷旁支护体在初期支护、切顶支护和后期支护三个时期的工作阻力分别建立力学计算模型,推导了三个时期的工作阻力表达式,对比得出,切顶阻力结果是最大的,应作为设计巷旁支护大砌体结构的技术参数。针对大砌体结构,运用Hilsdorf破坏理论计算得出抗压强度和承载力求解方法,并在巷道顶底板强度和巷旁支护强度相匹配原则指导下,确定了巷旁支护大砌体结构的宽度存在一个合理的范围,得出设计巷旁支护砌体结构的流程。采用数值模拟软件对整体墙和大砌块墙体进行研究发现,大砌体结构比整体承载性能变化不大,但在砂浆层和砌块的附近会产生较大的横向拉应力,成为结构中的薄弱部位,研究发现,砂浆和砌块的强度越相接近,会使整个砌体构筑物的受力越发均匀合理。因此在设计巷旁支护大砌体构筑物时应把砌块和砂浆的强度尽量接近。在砌块和砂浆的强度等级不变下,砌体结构的抗压强度会随构筑层数的增加而下降,五层的砌体强度会比三层的砌体强度降低4.6%左右,十二层的砌体强度会比三层的砌体强度降低6.8%左右,进一步说明了大砌体结构的可行性。最后结合龙矿集团盘道煤矿3203工作面的实际地质情况和以上研究成果,对3203工作面采用大砌体装配结构隔离墙成套技术进行了工程实践,较小的巷道变形量满足了留巷要求和可观的经济效益,同时对留巷机械化作业提供了宝贵的经验。
[Abstract]:The large masonry concrete structure is adopted to support the roadway side along the goaf, which overcomes the fact that the existing roadway side support can not have early strength and no dust at the same time. The problems of low labor intensity and rapid mechanization construction are discussed. This paper studies the requirements of large masonry structure as the mechanical characteristics of roadway side brace. On the basis of this research, the industrial test is carried out. Firstly, from the law of collapse activity of overlying strata along goaf roadway, it is concluded that passive caving is better than active collapse control. It is necessary to cut off the roof and caving along the lateral side of the supporting body in time to reduce the pressure when the overlying rock falls. The interaction between the movement of the overlying rock and the supporting body beside the roadway is analyzed. It is clear that the mechanical properties of the side support of roadway along the gob is the functional relation under the combination of bearing capacity and deformation. The working resistance in the three periods of roof cutting support and late support is established respectively, and the working resistance expression of the three periods is deduced. The comparison shows that the result of roof cutting resistance is the largest. It should be regarded as the technical parameter of designing roadway side support large masonry structure. According to the large masonry structure, the calculation method of compressive strength and bearing capacity is obtained by using Hilsdorf failure theory, and under the guidance of matching principle between roof and floor strength and support strength beside roadway, It is determined that there is a reasonable range of the width of roadway side support masonry structure, and the flow of designing roadway side support masonry structure is obtained. The whole wall and large block wall are studied by numerical simulation software. The load-bearing performance of large masonry structure is not much different from that of the whole structure, but large transverse tensile stress will be produced near the mortar layer and block, which will become the weak part of the structure. It is found that the strength of mortar and block is closer to each other. Therefore, the strength of block and mortar should be as close as possible in the design of large masonry structure by roadway. The compressive strength of masonry structure will decrease with the increase of building floor, the masonry strength of five stories will be about 4.6% lower than that of three-story masonry, and the masonry strength of 12 stories will be about 6.8% lower than that of three-story masonry. The feasibility of large masonry structure is further explained. Finally, combined with the actual geological conditions and the above research results of 3203 face of Pandao Coal Mine of Longshan Coal Mine Group, the complete set of technology of wall of large masonry assembly structure is used in 3203 face for engineering practice. The small amount of roadway deformation meets the requirements of roadway retention and considerable economic benefits, and provides valuable experience for mechanization of roadway retention.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD353

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