台阶式加筋土挡墙水平位移模式研究

Horizontal displacement modes of tiered geosynthetic reinforced soil retaining wall

加筋土挡墙水平位移大小及模式是结构设计的重要问题。以台阶式加筋土挡墙水平位移模式为研究对象,结合4组大比例模型试验和相关文献,分析墙面板水平位移的大小、形态及演化模式。主要结论包括:墙顶荷载作用下台阶式加筋土挡墙最大水平位移均发生在各级墙顶位置,台阶越宽,位移越小。上墙墙面水平位移沿墙高分布曲线由线性规律逐渐转变成指数规律,下墙墙面水平位移沿墙高分布曲线呈对数规律。考虑台阶宽度对下墙墙面水平位移的影响,建议墙间临界台阶宽度为下墙墙高的2/3。上墙墙面板基础底面会沿下墙墙顶发生平移,平移量随台阶宽度及墙面板基底摩擦力的增加而减小,平移方向受诸多因素影响。适当增加下墙上部及上墙下部的筋材密度或筋材长度可以有效减小墙面水平位移。该研究成果为类似结构的应用提供借鉴和参考。

The magnitude and modes of horizontal displacement of reinforced soil retaining walls are important to structural design. Based on four large scale model tests and relevant literature, the magnitude,forms and evolution modes of horizontal displacement of tiered geosynthetic reinforced soil retaining walls are investigated. The following conclusions are obtained from the tests：the maximum horizontal displacement of retaining walls appears at the top of each retaining wall,and the displacement decreases with increasing step width;The horizontal displacement distributions along the upper walls change gradually from linear curve to exponential,while the distributions along the lower walls are logarithmic curves;Considering the effect of step width on the lower wall horizontal displacement,the critical step width is suggested to be 2/3 of the lower wall height;The panel bottom layers of upper walls translate along the top layers of lower walls,the translation decreases with increasing step width and frictional resistance of panel bottom layers,and the translational direction is influenced by many factors; The horizontal displacement could be reduced by increasing numbers of geosynthetics layers or geosynthetics length in the bottom part of the upper wall and the top part of the lower wall. The results of this study can provide reference for similar structural applications.