岩体裂隙网络渗流变水温影响分析  

Analysis of influence of variable water temperature on seepage in fracture network of rock mass

作　　者：徐维生[1,2,3] 周创兵[1,2] 

机构地区：[1]武汉大学水资源与水电工程国家重点实验室,武汉430072 [2]武汉大学水利水电学院,武汉430072 [3]长江科学院水利部岩土力学与工程重点实验室,武汉430010

出　　处：《岩土力学》2014年第1期204-210,共7页Rock and Soil Mechanics

基　　金：长江科学院开放研究基金资助项目(No.CKWV2012308/KY);博士后基金资助项目(No.2012M521467);国家重点基础研究发展计划(973)项目(No.2011cb013506)

摘　　要：考虑岩体裂隙渗流变水温影响,推导单裂隙变水温水流近似解析解和有限元解,在此基础上分别建立裂隙二维网络变水温渗流数值求解方程,分别对应裂隙网络变水温渗流分析的近似解析法和子结构法。分析变温水流运动规律发现:(1)单裂隙内水流水头与水力坡降成非线性关系,当水流由高温区向低温区流动时,水头分布曲线为凸曲线,此时按线性渗流简化水头整体偏小;当由低温区向高温区流动时,水头分布曲线为凹曲线,此时按线性渗流简化水头整体偏大。(2)单裂隙内,高水温处水力坡降小,低水温处水力坡降大;裂隙平均水温越高,流速越快;裂隙网络内存在与裂隙宽度相似的温度偏流效应,即交叉节点水流有偏向水流温度高的裂隙流动的趋势。在温度较高和温度梯度较大的区域,应该考虑水流温度变化对渗流场的影响。Approximate analytical solution and finite element solution for the water flow of single fracture and variable water temperature considering the impact of water temperature on rock fracture seepage have been deduced. Based on the analytical formulas, the seepage numerical equations for two-dimensional fracture network under variable water temperature are formed, which apply to the approximate analytical methods and sub-structure method to variable water temperature analysis of fracture network seepage respectively. Some results can be found as follows.（1） The water head and the hydraulic gradient in single-fissure are nonlinear dependence. Seepage curve is convex curve when the current flow from the higher temperature area to the lower temperature area. In the condition, the water head slants low under liner seepage simplification. On the contrary, seepage concave is convex curve when the current flow from the lower temperature area to the higher temperature area, and the water head slants high.（2） In a single fracture, the hydraulic gradient is smaller in higher temperature area and is larger in lower temperature area. Higher the average water temperature of fracture is, and faster the flow velocity is. There is deflection effect caused by temperature in the fracture network. In the crossing nodes fluid tends to flow to the higher temperature area. Consequently, the effect of temperature change to seepage should be taken into account in the region of high temperature and high temperature gradient.

关 键 词：岩体裂隙网络 渗流 子结构法 变水温 温度偏流效应 

分 类 号：O357[理学—流体力学]