某地下水库在不同降雨条件下非稳定渗流分析

降雨入渗是地下水库主要来水之一，为了研究降雨对地下水库水位的影响以及分析地下水库的蓄水能力，分别以设置单道防渗地下坝的单库和多道防渗地下坝库群形式为研究对象，基于GeoStudio有限元软件中的Seep/W模块建立二维有限元模型，研究在不同降雨强度和雨型下的地下水库非稳定渗流场变化。降雨强度考虑年平均降雨量和年最大降雨量，持续时间为1年。降雨雨型考虑总降雨量为100 mm的平均型、前锋型、中锋型和后锋型。计算结果表明，在不同降雨强度下单库的地下坝前上游水位增加了71.1%，下游水位增加了11.7%。库群水位变化剧烈主要集中在1号和6号储水空间，水位增加量最高分别为8.8 m和12.5 m，而处于中间的储水空间水位变化较平缓；单库的整体水位变化较小，而库群主要对各个储水空间的水位影响较大，对取水有利；不同降雨雨型下对单库和库群上、下游表层孔压达到最大值的时间，以及表层体积含水量所能达到的峰值有一定的影响，且在前锋型最大含水量持续时间最长。研究成果可为地下水库在降雨条件下的蓄水提供一定的参考。 Rainfall infiltration is one of the main sources of water for the underground reservoir.The influence of rainfall on the groundwater reservoir water level and the water storage capacity of the groundwater reservoir are investigated in this study with a single reservoir of single channel anti seepage underground dam and a reservoir group of multi channel anti seepage underground dam.A two dimensional finite element model was established to estimate the unsteady seepage field of the groundwater reservoir under different rainfall intensities and different rainfall patterns,with the Seep/W module in GeoStudio finite element software.Rainfall intensity was chosen by taking into account annual average rainfall and annual maximum rainfall for a period of 1 year.Rainfall types include average type,forward type,center type and post peak type,with a total rainfall of 100 mm.The simulation results show that the upstream water level of the single base underground dam increased by 71.1% and the downstream water level increased by 11.7% under different rainfall intensities.The water level changes are mainly occurred in the #1 and #6 water storage spaces under multiple water storage spaces in an actual underground reservoir group,and the maximum water level changes are 8.8 m and 12.5 m under average rainfall and maximum rainfall,respectively.The water level in the middle storage space has only a minor change.The single reservoir has little changes of an overall water level.The installation of the reservoir group has a great influence on the water level for each water storage space,which might be beneficial to the water intake.Under different rainfall patterns,the pressures of the upper and lower surface pores of the single reservoir and the reservoir group reached their maximum.The peaks of the surface water content could be affected,and the maximum water content lasts the longest time with forwardtype rainfall.The research results provide a reference for the groundwater reservoir to store water under different rainfall conditions. 国家自然科学基金（51679193）