时变渗透特性的底板中水渗流过程分析  

Analysis on the seepage flow of water in coal seam floor with variable permeability paramters

作　　者：吴增光[1] 四旭飞[1] 杨敏[2] 

机构地区：[1]山西潞安环保能源开发股份有限公司,山西长治046204 [2]中国矿业大学理学院,江苏徐州221008

出　　处：《湖南科技大学学报（自然科学版）》2010年第1期62-66,共5页Journal of Hunan University of Science And Technology：Natural Science Edition

基　　金：国家重点基础研究发展计划(2007CB209400;2006CB202210);国家自然科学基金项目(50674087;50534090;50834005);中国高校博士点学科专项科学研究基金项目(20060290504);江苏省自然科学基金(BK2007029)

摘　　要：为了研究变渗透特性围岩中水渗流的稳定性,建立了一种渗透率、非Darcy流β因子和加速度系数按时间的反正切函数变化的渗流系统动力学模型.利用数值方法讨论了渗流速度的演化规律,论述了突水是否渗流失稳的表现.研究表明:由于非Darcy流β因子恒为正值,渗流系统总是稳定的;当渗透特性随时间变化时,渗流速度从一稳定值平滑地过渡到一新的稳定值,新的稳定值与原稳定值之比可以增大到几万至几百万倍,但是总是有限的;突水是岩层结构破裂引起的渗流速度快速或急剧变化,但渗流速度不可能无止境地增大,即渗流不可能失稳.用渗流失稳解释突水是不合理的.On the consideration of the change of seepage properties of coal floor affected by mining, a dynamic model, for non-Darcy flow of water in coal floor variable permeability parameters, was established, the steady state and its stability were taken into account. On the assumption that the permeability, non-Darcy-flow- β -factor and acceleration coefficient, changed as anti-tangent functions of time, evolutions of seepage velocity were worked out by numerical methods. Whether water-inrush is a reflection of the instability of seepage of water in coal floor was expounded based on the comparison of the steady value of seepage velocity post the change with that before the change. It shown that： （ 1 ）The system is always stable because the non-Darcy-flow-β-factor is positive. （2）Seepage velocity smoothly change from a steady value to a new steady value, the ratio of the new steady value over the original steady value might increase hundreds of thousand times or even more, but it is always finite. （3）Water-inrush goes with the failure of rock strata, but seepage velocity can not increase unendingly, so seepage flow can＇t be unstable. It can be concluded that it is not reasonable to explain the mechanism of water-inrush from the point view of seepage instability.

关 键 词：时变渗透特性 底板 渗流 稳定性 突水 

分 类 号：TU457[建筑科学—岩土工程]