蓄洪期路基边坡的含水特性

基于蓄洪区路基边坡在使用期经常受洪水浸泡,对路基边坡含水量的影响进行研究.首先定性分析正常使用期及蓄洪期各种环境的影响,在此基础上,引入Richards方程并根据Galerkin加权残量原理建立非饱和土非稳态流有限元格式,采用Dirichlet条件模拟边坡浸水的常水头条件；然后,引入Fredlund提出的非饱和土土水特征曲线模型及基于该模型导出的非饱和土渗透曲线预测方法,对实际工程土进行计算分析,获得相关计算参数.应用该方法对蓄洪条件下路基边坡的孔压及含水量分布进行计算分析.研究结果表明:蓄洪条件下路基可在较短的时间内达到稳定流状态,在工程设计中有必要考虑含水量变化引起的路基边坡问题.

Water content distribution in embankment subjected to floodwater

Based on the fact that the embankment in floodwater storage district will be influenced by flood frequently,the water content distribution in embankment subjected to floodwater was studied.The effect of circumstance in normal and flood storage period were analyzed firstly.Based on this,the Richards’ equation was introduced,and FEM format for relevant unsteady state flow of unsaturated soil was deduced by Galerkin’s weighted residual method,and the normal head pressure condition was taken into account by Dirichlet’s theory.Then,the Fredlund’s model of soil water characteristic curve for unsaturated soil,as well as the method to estimate the unsaturated premeability coefficient were introduced to analyze the real soil,and the calculation parameters were obtained.Lastly,the method was applied to analyze embankment subjected to floodwater,and the pore water pressure and water content distributions were obtained.The results indicate that flow in embankment subjected to floodwater can soon reach steady state,and embankment slope unstability caused by water content change should be considered in engineering practice.