基于ZoneBudget的坝址区渗流量分析

水电工程坝址区渗流量的确定对于工程设计施工具有重要指导意义。应用地下水数值模拟程序MODFLOW建立了理想条件下坝址区三维渗流模型,该模型利用WALL边界来刻画大坝,较好地模拟了坝址区的渗流特征。以水电规范中常用的解析解作为参照,着重讨论了应用ZoneBudget进行水均衡分析时,均衡单元的设置对坝基、绕坝渗流量的影响。对比分析结果表明,基于数值解的渗流量与解析解的结果有较大差异,数值解的渗流量与均衡单元的设定范围呈正相关。解析法求解渗流量具有较大的不确定性,而在利用数值法计算此问题时,也应充分论证均衡单元设置对计算结果准确性的影响。

Analysis of seepage at dam site by ZoneBudget

The estimation of seepage at dam site is important to the design of hydropower station. A synthetic 3-D groundwater flow model is built by using Visual MODFLOW 4. 0 under ideal conditions and the WALL boundary package is used to describe the dam, which can well depict the seepage characteristics at the dam site. Taking the analytical solution of the related specifications as a contrast, for the water budget analysis by ZoneBudget, we discussed the influence of budget unit arrangement on the seepage calculation of dam foundation and around dam. The comparison shows that there is a relatively large difference between the seepage numerical solution and the analytical solution, and the latter has a larger uncertainty. Moreover, the numerical simulated value increases with the budget range of ZoneBudget; therefore, the influence of budget unit arrangement on calculation results should be fully demonstrated.