基于光滑有限单元法的土石坝无压渗流场数值模拟  

Numerical simulation of unconfined seepage field of earth-rock dams based on smoothed finite element method

作　　者：戴前伟[1,2] 孔重阳 雷轶 张彬[1,2] 韩行进[3] DAI Qianwei;KONG Chongyang;LEI Yi;ZHANG Bin;HAN Xingjin(School of Geosciences and Info-physics,Central South University,Changsha 410012,China;Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring(Central South University),Ministry of Education,Changsha 410012,China;Wuling Power Corporation Ltd.,Changsha 410004,China)

机构地区：[1]中南大学地球科学与信息物理学院,湖南长沙410012 [2]中南大学有色金属成矿预测与地质环境监测教育部重点实验室,湖南长沙410012 [3]五凌电力有限公司,湖南长沙410004

出　　处：《水资源与水工程学报》2021年第5期194-201,共8页Journal of Water Resources and Water Engineering

基　　金：国家自然科学基金项目(41704128、41874148);国家重点研发计划项目(2018YFC0603900)。

摘　　要：获得自由面准确位置是无压渗流分析中最被关注的问题。采用光滑有限元法对土石坝无压渗流场进行数值模拟,对不同模型的自由面位置进行求解,研究了渗透异常体对自由面和渗流参数的影响。根据梯度光滑技术,建立了无压渗流问题的光滑有限元模型,该方法的优势在于将单元面积分优化为沿单元边界的线积分,简化了边界相交单元的内部积分过程,降低了单元畸形对计算结果的影响。通过将矩形均质坝和梯形均质坝的经典算例计算结果和其他数值方法的结果进行对比,说明了本文提出的方法的可行性。进一步研究了不同的渗透率异常体对水头分布、渗流速度和流体压力等渗流参数的具体影响,这些结果为利用渗流参数分布的变化反演渗透异常体位置,以及进行土石坝多场耦合提供了理论依据和可行策略。In the analysis of unconfined seepage,the key issue is to find the location of the free surface.Here,the smoothed finite element method(S-FEM)was used to calculate the location of the free surface in the saturated seepage region,and to simulate the influence of different permeability anomalies on the free surface and seepage parameters of earth-rock dams.According to the gradient smoothing technique,a smoothed finite element model for the unconfined seepage was established.The advantage of this method is that the element area is divided into line integrals along the boundary of the element,which simplifies the internal integration process of the boundary intersecting elements and reduces the influence of the element deformation on the calculation results.The calculation results of typical rectangular and trapezoid homogeneous dams were then compared with those of other numerical methods,and the effectiveness of the method proposed in this paper was verified.Meanwhile,the influence of different permeability anomalies on the seepage parameters such as water head distribution,seepage velocity and fluid pressure was further studied.These results can provide a theoretical support and feasible strategy for multi-field coupling of earth-rock dams,as well as for inversing the location of the permeability anomalies by changing the distribution of seepage parameters.

关 键 词：土石坝 无压渗流分析 自由面搜索 光滑有限元 渗流场 

分 类 号：TV641[水利工程—水利水电工程]