论文部分内容阅读
随着煤矿开采向深部延伸,陷落柱、断层等含破碎岩体地质构造突水成为威胁煤矿安全生产的重大灾害之一。近年来虽有学者从破碎岩体流固耦合动力失稳的角度研究地质构造突水机理,但没有考虑质量流失对破碎岩体渗透特性的影响。展示了自主研制的一套可实现质量流失的破碎岩体渗透试验系统,包括加载系统、数据采集系统、水压供给系统及特制渗透仪装置,并利用该渗透试验系统,通过改变破碎岩体的配比、应力状态等条件,计算并分析充填物质量流失率、渗透率、流量等参数的变化规律,初步研究了破碎岩体的变质量渗透特性。结果表明:1)自主研制的破碎岩体变质量流固耦合试验系统通过渗透仪蜂窝状的活塞、带有缺口的溢水筒等的独特设计,实现了渗流作用下充填物颗粒的自由迁移,具有较好的开放性。2)质量流失条件下破碎岩体的渗透性变化可分为3个阶段,即初始渗流阶段、渗流突变阶段和渗流稳定阶段。在初始渗流阶段,破碎岩体渗透率缓慢变化,孔隙率逐渐增大;在渗流突变阶段,渗透率在极短时间内增大数倍甚至几十倍,孔隙率快速增大;在渗流稳定阶段,渗透率和孔隙率随时间基本保持不变。3)随渗透时间增加,破碎岩体充填物颗粒不断迁移流失,渗透性不断增强并最终发生渗流突变,这表明充填物颗粒迁移流失是引起破碎岩体渗流突变的重要原因。
With the deep extension of coal mining, collapse columns, faults and other geological structures with broken rock inrush as a threat to coal mine production safety one of the major hazards. In recent years, although scholars have studied the mechanism of waterburst in geological structures from the perspective of fluid-structure interaction of broken rock mass, they did not consider the effect of mass loss on the permeability characteristics of broken rock mass. This paper presents a set of self-developed permeable test system of rock mass which can achieve mass loss, including loading system, data acquisition system, water pressure supply system and special permeation device. By using this permeability test system, Mixing ratio, stress state and other conditions, the changing rules of the mass loss rate, permeability rate and flow rate of the filling material were calculated and analyzed. The variable mass infiltration characteristics of the fractured rock mass were preliminarily studied. The results show that: 1) The self-developed variable mass-fluid-solid coupling test system of fractured rock mass achieves the free migration of filler particles under seepage by means of the unique design of honeycomb-shaped piston of permeable honeycomb, Better openness. 2) Under the conditions of mass loss, the permeability of broken rock mass can be divided into three stages, that is, the initial seepage stage, the catastrophe stage and the seepage stabilization stage. In the initial seepage stage, the permeability of broken rock mass changes slowly, and the porosity increases gradually. At the stage of seepage mutation, the permeability increases several times or even tens of times in a very short time and the porosity increases rapidly. , The permeability and porosity remain basically unchanged over time. 3) With the increase of infiltration time, the particles of the fractured rock mass continuously migrate and lose, the permeability increases continuously and the seepage mutation finally occurs, which indicates that the migration and loss of the filler particles are the important reasons causing the seepage mutation of the fractured rock masses.