考虑垂向重力作用的堤坝离心模型渗流特性研究

Seepage Characteristics of Centrifugal Dam Models Considering Vertical Gravity Effects

对堤坝渗流离心模型试验中的垂向重力作用进行分析,推导同时考虑重力场和离心力场下的渗流控制方程.改进变网格有限单元法,求解堤坝模型稳定渗流区域的自由面位置和总单宽流量,并对重力作为渗流驱动力和渗流阻力的情况分别分析.结果表明:当离心机臂长Rb≥2 m且相似比尺N≥60时,堤坝离心模型计算结果与解析解答较为接近;当重力作为渗流阻力时,堤坝模型计算结果与解析解答相差较大,因此需要合理设置上、下游水位位置,使得试验结果更加准确,为堤坝渗流离心模型试验提供参考.

This study analyzes the vertical gravity effects in centrifugal dam seepage model experiments.Seepage control equations that simultaneously consider the gravitational and centrifugal force fields are derived.The finite element method with an improved variable mesh is employed to solve for the free surface position and total unit width flow rate in the stable seepage region of the dam model.The effects of gravity as a driving force and resistance in seepage are analyzed separately.The results indicate that when the centrifuge arm length(Rb)is greater than or equal to 2 m and the similarity ratio(N)is greater than or equal to 60,the calculated results of the centrifugal dam model closely match the analytical solutions.However,when gravity acts as the seepage resistance,there is a significant discrepancy between the dam model calculations and the analytical solutions.Therefore,it is necessary to set the upstream and downstream water level positions during the experiment to enhance accuracy and provide valuable insights for centrifugal dam seepage model experiments.