隔堤填筑路堤的稳定性及变形破坏模式分析

Analysis of stability & deformation and destruction mode of road embankment built aside dam

隔堤填筑路堤或沿原河堤加宽是高等级公路经常采用的改扩建方式,路堤填筑后对原河堤的稳定性将产生怎样的影响,路堤自身的稳定性及变形破坏具有何特征,是目前沿河公路扩建工程中亟需解决的问题。结合依托工程的现场勘察和室内外试验结果,建立有限元模型,对路堤填筑前后及不同水位渗流条件下原河堤及路堤的稳定性进行了模拟计算和分析。计算结果表明:路堤填筑有利于提高原河堤的稳定性,稳定安全系数可提高约26%;隔堤填筑的路堤受多因素共同作用,容易产生较大的差异沉降,且工后固结时间长、沉降量大,工后沉降达总沉降的35%左右;隔堤填筑的路堤一般仅在远离原河堤一侧边坡发生剪切失稳破坏,渗流对路堤稳定性的影响较小,且不会改变路堤的破坏模式。数值模拟计算可以在工程实施前揭示隔堤填筑路堤的稳定性及变形破坏模式,从而为后一步的工程对策设计提供依据和参考。

Fill road embankment aside riverbank or widen riverbank as road embankment is often used in highway extend.The road embankment along riverbank built has what influences to the stability of riverbank,and has what characteristics of the stability,deformation and destroy mode to the road embankment.These are the main problems to be solved in river levee highway extend.Based on the results of local reconnaissance and in-situ as well as laboratory test,a finite element model is built to carry out analogy calculation and analysis of the stability of the riverbank and the road embankment under different water level before and after the road embankment built.The results indicate that： the build of road embankment is propitious to enhance the stability of the riverbank,the safety factors are increased about 26%;the embankment built aside riverbank is easy to generate differential settlement and big settlement.The total settlement could increase 35% as the widen of embankment.the road embankment can occur whole shear destroy on the slope far from the dam,and the seepage has little influence to the stability and would not change the destroy mode of the embankment.Numerical simulation can disclose the stability and destroy mode of the road embankment before the project built.Simulation results could offer reference and gist for the next engineering countermeasure design.