煤矿巷道底臌机理及其控制技术研究

发布时间：2018-06-17 01:06

本文选题：巷道底臌 + 影响因素　；参考：《西安科技大学》2016年硕士论文

【摘要】：在煤矿的生产过程中,巷道在开挖后或受到采动的影响时,底板经常会出现底臌现象,其中剧烈的底臌会导致巷道断面缩小、阻碍运输和人员行走、妨碍通风等诸多问题。由于开巷后,多数情况下都是仅针对顶板和两帮采取支护措施,往往忽略了底板的变形,这也加剧了底臌的发生。由此可见,针对巷道的底臌机理及其控制措施进行研究对于维护巷道的稳定性、保证煤矿的安全生产具有重要的现实意思。本文采用理论分析与数值模拟相结合的方式,结合某巷道具体的工程地质环境,对底臌发生的机理以及不同的控制措施进行了深入的研究。主要工作和结论有:(1)通过对底臌影响因素的研究分析,认为巷道底臌的主要影响因素为底板岩层的物理力学性质、矿山压力以及支护强度和巷道断面形状。通过对底臌的成因分析,将底臌的主要类型分为应力型、膨胀型、软化型。依据巷道底板不同的破坏形态,对底臌的特征进行了分析。(2)通过对巷道底板破坏形式的研究,建立了在支承压力作用下底板岩层失稳的力学模型,将底板划分为三个区域:主动破坏区、挤压过渡区和挤压被动区。分析可知,底板岩层的变形规律为:主动区岩体在垂直方向上受压缩,该区域岩体势必会遭到破坏,形成破碎区;同时,在水平方向上,主动区岩体必然会膨胀,进而挤压过渡区岩体,并将应力传递到这一区;过渡区岩体继续挤压被动区,从而被动区有了被迫向上运动的趋势,并在竖直向上的底板应力作用下发生底臌。建立底板的四边固支矩形薄板模型,在矩形薄板中选取单位宽度的单元条,在竖向均布力作用下对该单元条在两边固支的边界条件下进行挠度计算,将其作为底臌量的估计值,通过具体的工程算例,验证了底臌量估计式的可行性。对底臌量估计公式中的主要影响参数进行了分析,为底臌防治措施的提出提供了理论依据。(3)采用FLAC3D数值模拟软件对具体工况和地质条件下某巷道开挖后的围岩变形进行了数值分析,通过其底板变形量与底臌量估计式所计算出的底臌量进行对比,验证了数值模型的合理性和正确性。在原支护方案无法解决底臌问题的前提下,通过对底臌主要影响因素以及底臌量估计式中参数分析的基础上,提出底臌治理的不同方案,即开挖卸压槽、底板锚杆加固、切槽卸压与底板锚杆联合支护治理底臌三种方案。分别对三种治理方案进行数值模拟分析,对其底臌防治效果进行了对比,得出最佳治理方案。
[Abstract]:In the process of coal mine production, floor heave often occurs in the roadway after excavation or under the influence of mining, among which violent floor heave will lead to roadway section shrinking, hinder transportation and personnel walking, hinder ventilation and many other problems. After the roadway is opened, the supporting measures are taken only for the roof and the two sides in most cases, and the deformation of the floor is often neglected, which also intensifies the occurrence of floor heave. It can be seen that the study on the mechanism of floor heave and its control measures is of practical significance for maintaining the stability of roadway and ensuring the safety of coal mine production. In this paper, the mechanism of floor heave and different control measures are deeply studied by combining theoretical analysis with numerical simulation and combining with the concrete engineering geological environment of a roadway. The main work and conclusions are as follows: (1) through the study and analysis of the influencing factors of floor heave, it is considered that the main influencing factors of roadway floor heave are the physical and mechanical properties of floor rock, mine pressure, support strength and roadway section shape. By analyzing the causes of floor heave, the main types of floor heave are divided into stress type, expansion type and softening type. According to different failure patterns of roadway floor, the characteristics of floor heave are analyzed. (2) by studying the failure form of roadway floor, a mechanical model of rock layer instability under the action of supporting pressure is established. The bottom plate is divided into three regions: the active failure zone, the extrusion transition zone and the extrusion passive zone. According to the analysis, the deformation law of the bottom rock layer is: the rock mass in the active zone is compressed in the vertical direction, the rock mass in the area is bound to be destroyed to form a broken area, and at the same time, in the horizontal direction, the rock mass in the active zone is bound to expand. Then the rock mass in the transition zone is squeezed and the stress is transferred to the zone; the rock mass in the transition zone continues to squeeze the passive zone, thus the passive zone has the tendency of forced upward movement, and floor heave occurs under the action of vertical bottom stress. The rectangular thin plate model with four sides fixed on the bottom plate is established. The unit width element bar is selected in the rectangular thin plate. Under the action of vertical uniform force, the deflection of the element strip is calculated under the boundary condition of the two sides clamped up, which is regarded as the estimated value of the floor heave. The feasibility of the estimation of floor heave is verified by an engineering example. The main influence parameters in the estimation formula of floor heave are analyzed. This paper provides a theoretical basis for the prevention and treatment of floor heave. 3) numerical analysis of surrounding rock deformation after excavation of a roadway under specific working conditions and geological conditions is carried out by using FLAC3D numerical simulation software. The rationality and correctness of the numerical model are verified by the comparison between the floor deformation and the floor heave calculated by the estimation of floor heave. On the premise that the original support scheme can not solve the problem of floor heave, based on the analysis of the main influencing factors of floor heave and the analysis of parameters in the estimation formula of floor heave, different schemes of floor heave treatment are put forward, that is, excavation of pressure relief trough and reinforcement of floor anchor. Three schemes of combined support of groove relief and floor bolt for floor heave control. The numerical simulation and analysis of three treatment schemes were carried out respectively, and the control effect of floor heave was compared, and the best treatment scheme was obtained.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TD327.3;TD353

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