浅埋煤层顶板突水机理研究

发布时间：2018-02-02 01:13

  本文关键词： 浅埋煤层 顶板突水 固液耦合实验 隔水土层 导水裂缝　出处：《西安科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：本论文以榆神府矿区为研究背景,通过理论分析、物理相似模拟实验和数值模拟相结合的方法,对浅埋煤层上覆隔水土层受采动影响的稳定性以及隔水性等问题进行研究,为矿井突水预测提供了依据,研究结果对矿井安全生产具有一定的理论意义。针对三趾马红土的物理力学性质、水理性质,利用土力学相关知识对三趾马红土性质进行试验分析,为相似模拟和数值模拟的进一步研究打下基础。实验得出三趾马红土渗透性随上覆载荷增大不断减小,随水头压力增大渗透性增强。以榆神府浅埋煤层、薄基岩、厚土层下的中厚煤层为研究对象,通过固液耦合相似模拟实验研究隔水土层的下沉与关键层同步运动,由于受到水压以及水平挤压作用部分裂缝发生闭合,在开切眼和工作面上方裂缝发育较为明显由于铰接作用不易闭合;导水裂缝带的高度受到关键层的影响较为明显,实验表明在单一关键层的条件下关键层位置越高导水裂缝带的发育高度越低反之亦然。通过红外成像仪呈现了水的运移,表明水在岩层中运动不仅有纵向运动还有水平运动即表现为层流运动。覆岩上部隔水土层厚度不同隔水效果也不同,土层厚度与采高之比k≤4的条件下,隔水层将发生不可恢复的破坏,工作面突水较严重;土层厚度与采高之比4k15的条件下,隔水土层裂缝将会贯通,形成突水通道,但随着工作面的继续推进部分裂缝受到水平作用力与水压共同作用下将会愈合;土层厚度与采高之比k≥15的条件下,隔水土层裂缝不会贯通,不能形成突水通道。应用FLAC3D数值模拟软件,分析采动影响下围岩的位移场、塑性破坏区域、孔隙水压以及渗流等特征,通过对塑性区、孔隙水压云图以及渗流场的分析顶板发生突水区域主要集中在开切眼和工作面上方。利用数值模拟进一步验证了浅埋煤层顶板突水是由于隔水土层发生破坏,导水裂缝带贯穿隔水土层并沟通含水层而引起。
[Abstract]:In this paper, the Yushenfu mining area as the research background, through theoretical analysis, physical similarity simulation experiment and numerical simulation method combined. This paper studies the stability and water repellency of overlying soil layer affected by mining in shallow coal seam, which provides the basis for the prediction of mine water inrush. The research results have certain theoretical significance for mine safety production. Aiming at the physical and mechanical properties and hydrological properties of the red soil of the third toe horse, the properties of the red soil of the third toe horse are tested and analyzed by using the relevant knowledge of soil mechanics. The experimental results show that the permeability of red soil decreases with the increase of overburden and increases with the pressure of water head. Thin bedrock, thick coal seam under thick soil as the research object, through the solid-liquid coupling simulation experiment to study the subsidence of the impermeable soil and the synchronous movement of the key layer. Due to water pressure and horizontal extrusion, some cracks are closed, and the crack development is obvious because of hinge action is difficult to close in the opening and cutting hole and above the working face. The height of the water-conducting fracture zone is obviously affected by the critical layer. The experimental results show that the higher the position of the critical layer is, the lower the development height of the water-conducting fracture zone is, and vice versa. The water migration is shown by the infrared imager. The results show that the movement of water in rock is not only longitudinal motion but also horizontal movement, that is, laminar movement, the effect of water and soil barrier is different with the ratio of soil thickness to mining height k 鈮，

本文编号：1483283