破碎岩体非线性渗流突水机理研究现状及发展趋势

在收集整理国内外相关资料的基础上,从非线性渗流理论方程、非Darcy渗流试验和非线性渗流数值模型方法等方面总结目前破碎岩体非线性渗流突水研究现状,认为破碎岩体渗流具有突水通道的非Darcy渗流特性、3种流场(Darcy层流、非Darcy高速流及Navier-Stokes紊流)动力学系统的统一性和突水3要素(含水层水源的Darcy流、突水通道的非Darcy流和开采扰动作用)中的应力扰动特性。据此,提出了破碎岩体非线性渗流突水机理研究的发展趋势:从矿山采动岩体渗流突水3要素这一渗流特征出发,通过试验和现场测试研究不同围压、水力梯度和流速条件下破碎岩石渗流规律,建立考虑应力作用的耦合Darcy,Forchheimer和Navier-Stokes方程混合流场的模型,提出有限单元弱形式和有限体积法耦合积分解算混合流场方法,把采动应力作用下含水层、冒落岩体破碎带和巷道整个突水水流路径连接在一起,Forchheimer流域的边界流量压力是动态变化的,可以有效解决破碎岩体非线性渗流模型存在的问题,能比较合理模拟采动应力作用下矿山突水瞬态流动全过程。

State of the art and trends of water-inrush mechanism of nonlinear flow in fractured rock mass

The state of the art of nonlinear seepage theories，non-Darcy flow tests and nonlinear flow numerical models of water-inrush induced by nonlinear flow in fractured rock mass are summarized according to the available data.It is found that both three flow fields，i.e.，Darcy flow，the high-velocity non-Darcy flow and the turbulent flow，and three principal factors，i.e.，Darcy flow of the water resource，the high-velocity non-Darcy flow in water-inrush channel and the influence of mining disturbances，exist together in the process of mining induced water inrush.This paper holds that non-Darcy flow in water-inrush channel，the unity of three dynamic flow fields and the stress disturbance characteristics of the three principal factors are quite important to the flow in fractured rock mass.Based on the above views，the trends of water-inrush in fractured rock mass have been put forward.Considering the three principal factors of mining-induced water inrush，the laws of the seepage in fractured rocks under different confining pressures，hydraulic gradients and flow rates will be researched according to the experiment and the field investigation.The aim is to establish a coupled model of Darcy equation，Forchheimer equation and Navier-Stokes equation with the effect of mining stress.The corresponding model will be studied by numerical method，which is proposed on the basis of coupling integral equations of the weak form of the finite element and the finite volume technique.In the model，both the flow and the pressure boundaries of the Forchheimer flow zone are dynamic as time changes.In this way，the problems of the nonlinear seepage models in fractured rock mass can be solved effectively，and the complete flowing process of mining induced water-inrush can also be simulated reasonably.