格栅加筋黏性土挡墙黏弹塑性有限元分析

Analyses of FEM Based on the Visco-Elasto-Plasticity of Reinforced Cohesion Soil Retaining Wall by Geogrids

研究目的:针对格栅加筋黏性土挡墙,采用5元件西原流变模型和黏弹性模型分别考虑黏性回填土与筋材的流变特性,通过合理考虑筋材、填土与面板间的相互作用效应和加筋逐层填筑过程,编写了分析加筋黏性土挡墙工作性能的二维有限元数值程序,并以Denver黏性土试验挡墙为例,对加筋黏性土挡墙长期工作性能进行评价。研究结论:有限元数值模拟结果与实测值吻合较好;挡墙面板侧向变形及试验墙顶部沉降受土体和筋材的蠕变特性影响明显;筋材应力在开始阶段变化明显,且有不同程度的增加,随着载荷持续时间的增加,筋材应力开始变小,筋材处于应力松弛状态。

Research purposes： 5 -element Nishihara ＇s rheologieal model of cohesion soil and creep model of geosynthetics are used to study long term behaviors of reinforced cohesion soil retaining wall. Additionally, the interaction effects of reinforcement and fills, panel and fill and panel and panel are rationally considered. The layer - by - layer filling process of backfills of retaining wall is also simulated. Nonlinear computations based on 2 - D FEM are numerically implemented by hybrid algorithm in which the incremental scheme is incorporated. Furthermore, Denver test wall of cohesion soil has been simulated by proposed method here. Research conclusions：The simulated results agreed with the measured results well. Vertical displacement for top surface and lateral displacement for panel are affected by rheology of reinforced structure. Stresses of reinforcement increased with time at the beginning, during a specified time the stresses in it decreased and the reinforcement showed the behavior of relaxation.