【作者】 赵毅；

【导师】 张寅；

【作者基本信息】 辽宁工程技术大学 ， 工程力学， 2021， 硕士

【摘要】 随着水文地质条件较为复杂的大水矿山陆续开采,大水矿山顶板事故频发,富水工作面疏水前后顶板破断距离变化规律的研究显得尤为重要,因此,本论文围绕顶板疏水前后工作面来压步距变化问题,以葫芦素煤矿21103工作面为研究对象,以顶板疏水前后覆岩物理力学性质变化对顶板疏水进行表征,采用理论分析、物理相似模型试验和数值模拟等研究方法,开展综采工作面顶板疏水前后工作面来压步距变化规律研究,取得如下成果。(1)基于关键层理论,确定影响工作面来压步距的关键层,根据关键层初次和周期破断受力形式将关键层分别简化为固支梁模型和悬臂梁模型,利用弹性力学理论对其进行分析。通过理论分析分别得到工作面顶板疏水前后初次来压步距及周期来压步距。(2)以两种含水状态下多种覆岩物理力学性质测试结果及现场地质资料为基础,构建两组物理相似模型试验,确定了两组试验相似材料的配比方案,应力及位移监测方案。通过两组相似模型试验研究,分别得到顶板疏水前后工作面的来压步距。同时通过对相似模型试验结果进行分析可以得到关键层破断影响下覆岩垮落位移特征、覆岩应力变化规律及工作面回采过程中采动应力演化规律。(3)利用FLAC3D数值模拟软件通过建立两组数值模拟模型,模拟了顶板疏水前后工作面回采过程中围岩应力变化规律。结合理论分析可知关键层破断主要是受拉破坏,在模型开挖前在关键层内设置监测点,通过对各监测点应力值变化规律进行分析,可以得到顶板疏水前后关键层初次破断距离。(4)综合理论分析、相似模型试验和数值模拟结果对工作面顶板疏水前后工作面来压步距变化规律和围岩应力变化规律进行分析总结,为工作面顶板管理提供理论指导,同时为我国其他类似矿井解决此类问题提供借鉴。该论文有图45幅,表13个,参考文献73篇。更多还原

【Abstract】 With the continuous mining of Water-rich mines with complicated hydrogeological conditions,the roof accidents of Water-rich mines are frequent,and the research on the rule of the roof breaking distance before and after drainage in water-rich working face is particularly important,this paper focuses on the change of weighting step before and after roof drainage,taking 21103 working face of Hulusu coal mine as the research object,and characterizing roof drainage with the change of physical and mechanical properties of overburden before and after roof drainage,by means of theoretical analysis,physical similarity model test and numerical simulation,the variation law of weighting step before and after roof drainage in fully mechanized coal face is studied.(1)Based on the key layer theory,the key layer which influences the weighting step is determined,and the key layer is simplified into fixed beam model and cantilever beam model respectively according to the primary and periodic breaking force forms of the key layer,it is analyzed by the theory of elasticity.Through theoretical analysis,the first weighting step and periodic weighting step are obtained before and after roof drainage.(2)Based on the test results of physical and mechanical properties of multiple overburden rocks under two water-bearing conditions and the field geological data,two groups of physical similarity model tests are constructed,and the proportioning schemes of two groups of test similar materials are determined,monitoring scheme of stress and displacement.Through two groups of similar model tests,the weighting step of the working face before and after the roof drainage is obtained.At the same time,through the analysis of the similar model test results,we can get the caving displacement characteristics of the overlying strata under the influence of the key strata failure,the change law of the overlying strata stress and the evolution law of the mining stress during the working face mining.(3)Using FLAC3 D software to establish two sets of numerical simulation models to simulate the change law of surrounding rock stress in the process of working face before and after the roof drainage.Based on the theoretical analysis,it can be concluded that the failure of the key stratum is mainly tensile failure,and monitoring points are set in the key stratum before the model excavation,the first breaking distance of key stratum before and after roof drainage can be obtained.(4)Comprehensive theoretical analysis,similar model test and numerical simulation results are used to analyze and summarize the variation law of weighting step and surrounding rock stress before and after the roof drainage,it provides theoretical guidance for roof management of working face and reference for other similar mines in China to solve such problems.更多还原