【摘要】 液化型路堤边坡动力稳定性问题涉及岩土工程与工程地震两个学科领域,是边坡工程与砂土液化的交叉课题。采用天然地震记录为输入条件,应用Finn本构关系模型,运用有限差分法,对填土+砂土+卵砾土地层组合的路堤边坡进行了全时程动力分析,探讨了地震作用下路堤边坡的液化初步规律和稳定性。数值模拟结果表明:地震作用引起了路基饱和砂土有效应力急剧减小,并导致路基砂土液化,引起路堤变形破坏。孔隙水压力的积累与消散不仅与地震记录序列存在对应关系,也与砂土所处的位置和深度有密切关系。地表变形破坏主要表现为路堤顶面发生震陷和拉裂破坏,坡底面产生挤压隆起变形。地面以下的变形破坏主要包括土体剪切破坏和深部砂土液化引起的侧向流动破坏。更多还原

【Abstract】 Seismic liquefaction problems of road embankment slope are involved in two different fields which are geotechnical engineering and engineering earthquake.Therefore,it’s a cross topic of slope engineering and sand liquefaction.By means of Finn constitutive model,the dynamical stability and liquefaction failure mechanics of road embankment slope which is made up of fill,sand soil and gravel soil under natural seismic loading are simulated with finite difference method.The following results are obtained.Firstly the deformation and failure of road embankment slope under seismic loading are caused by subgrade sand liquefaction which results in the effective stress decreasing rapidly.Secondly the accumulation and dissipation of pore water pressure not only related to earthquake record sequence,but also have a close relation with the position and depth of saturation sand.Thirdly the ground distortion and destruction mostly appears as two aspects which are seismic subsidence at the top of embankment and uplift at the base of slope.Lastly the under-ground deformation and failure principally include shear failure of slope soil mass and lateral spreading of the deep layer induced by sand liquefaction.更多还原