基于VOF法的CSG坝非稳定渗流场数值分析  

Numerical Analysis to CSG Dam Unsteady Seepage Field Based on VOF Method

作　　者：甘创 蒋晓明 张登祥[1] GAN Chuang(School of Hydraulic Engineering,Changsha University of Science and Technology,Changsha 410114,China)

机构地区：[1]长沙理工大学水利工程学院,长沙410114

出　　处：《长春工程学院学报（自然科学版）》2021年第2期96-102,共7页Journal of Changchun Institute of Technology：Natural Sciences Edition

基　　金：湖南省水利厅项目(XSKJ2018179-26)——胶凝砂砾坝(CSG)抗渗性能关键技术研究的成果。

摘　　要：当前国内外对胶凝砂砾石大坝(CSG Dam)渗流场的研究均局限于稳定渗流场,但由于库水位的不断波动,大坝在运行期大都处于非稳定渗流状态,保证这种新型坝在库水位变化时的安全稳定非常重要。采用有限体积法及计算流体力学中的VOF(volume of fluid, VOF)法,对CSG坝两个极端工况下的非稳定渗流场进行模拟,获得孔隙水压力、浸润面、流速及流量的演变过程,结果表明:1)CSG坝体防渗效果良好,即使在面板防渗性能降低的情况下,浸润线也处于较低的高程;2)在水位上升阶段,坝踵附近在水位上升初期渗流量会出现不稳定波动,下游节点渗流量变化起步较晚,且需要经历一个较长的时间才能达到渗流稳定;3)水位下降时,坝体浸润面呈现中间高、两边低,上游高、下游低的趋势。一部分坝内渗水会向上游排出,产生的渗透压力不利于面板的稳定,建议在坝趾处采取排水措施,引导坝内渗水排出,减少对上游面板的不利影响。The current domestic and foreign studies on the seepage field of CSG Dam are limited to stable seepage fields, but most of the dams are in an unstable seepage state during operation.In this paper, the finite volume method and the VOF(Volume Of Fluid) method in computational fluid dynamics are used to simulate the unsteady seepage field of the CSG dam under two extreme conditions to obtain the pore water pressure, infiltration surface, velocity and flow rate.During the evolution process, the conclusions show that: 1) CSG Dam has a good anti-seepage effect.Even when the anti-seepage performance of the panel is reduced, the infiltration line is at a lower elevation;2) During the rising stage of the water level, the upstream node rises at the water level.The initial seepage flow will be unstable and fluctuate.The downstream node seepage flow changes start late, and it takes a long time to reach the seepage stability;3)When the water level drops, the infiltration surface of the dam body shows a trend of high in the middle, low on both sides, high in the upstream and low in the downstream.Part of the seepage in the dam will be discharged upstream, and the resulting seepage pressure is not conducive to the stability of the slab.It is recommended to set drainage measures at the dam toe to guide the leakage of the dam and reduce the adverse impact on the upstream slab.

关 键 词：CSG Dam VOF法 立方定律 非稳定渗流场 

分 类 号：TV641[水利工程—水利水电工程]