中、小型土石坝渗流场三维有限元分析方法及应用

3-D Finite Element Method of Seepage Field of Middle-small Earth-rock Dam and its Application

针对中、小土石坝工程的特点以及存在渗流安全的问题,采用改进的节点虚流量法,得到求解土石坝渗流问题的有限元分析方法,并编制Fortran程序.依托某土石坝工程,建立三维有限元渗流场计算模型,对正常蓄水时该坝坝体和坝基的渗流场进行了仿真计算,得到了相应的水头分布、浸润线以及渗漏量,并对该坝设计防渗体系下坝区渗流场规律和特点进行了分析.结果表明,该方法对中、低土石坝渗流溢出点和浸润线定位合理、准确,能够很好地模拟坝区渗流场规律,可为中、低土石坝的渗流安全评价提供参考.

In view of the problem of seepage safety and the character of middle-small earth-rock dam project,the method of improved nodal virtual flux was employed to obtain the FEM of seepage problem, and the Fortran procedure was programmed. Based on an earth-rock dam project, the 3D finite element model was built, and the seepage field of the dam body and foundation was simulated. According to the result of calculation, the water head distribution, saturation line and leakages were obtained, and the rules and characteristics of steady seepage field under design impervious system were analyzed. The results indicated that the method can exactly locate the key overflow point and saturation line of middle-small earth-rock dam and well predict seepage field in dam area, and the calculated results can provide reference for the seepage security evaluation of middle-small earth-rock dam.