钢塑复合筋带挡土墙病害及成因

Analyses of defects and causes of steel-plastic compound reinforced retaining wall

针对加筋土挡墙在使用过程中会出现竖向沉降、路面纵横开裂及挡墙外倾变形等病害,甚至发生局部塌陷,从而影响交通运营的问题。通过对哈尔滨市加筋土挡墙的病害调查,总结了病害的主要形态。选取典型病害段,利用MIDAS-GTS NX有限元软件,分析了填土性质、填土脱空、筋带断裂、渗水及汽车荷载等因素对运营后挡墙水平变位及筋带轴力的影响,系统地研究了加筋土挡墙病害的成因。研究认为:挡墙的病害是土压力、车辆作用、路面渗水等诸多因素综合作用的结果。填土的c、φ值是挡墙水平变位的敏感性因素,路面开裂渗水,使得填土含水量上升,导致填土的c、φ值下降,这是导致挡墙水平外倾的重要因素;筋带断裂、填土脱空及汽车荷载超载也是导致挡墙水平变形重要因素之一,本文研究成果为加筋土挡墙的养护维修与加固提供了依据。

Reinforced retaining wall has been widely used in highway construction, however, the vertical settlement, cross cracks of the pavement and outward-dipping deformation and other defects have occurred. These defects can even lead to partial collapse that impacts the traffic. Based on the defect survey of the reinforced retaining wall in Harbin City, the main forms of the defects are summarized. A section of road with typical defects is selected as an example to investigate the influences of fill properties, fill voids, ribbon fracture, seepage, traffic load and other factors on the horizontal deflection and the axial force using finite element software MIDAS-GTS NX. The causes of the defects of the reinforces retaining wall are systematically analyzed. Results show that the defects of the retaining wall are caused by the integrated actions of soil pressure, traffic load, pavement seepage and many other factors. The values of C and of the fill are the sensitive factors of the horizontal displacement of retaining wall. The pavement crack and seepage lead to the moisture increase, resulting in the decreases in Cand φ which is the factor of the outward-dipping deformation. Ribbon fracture, fill void and traffic load are important factors that lead to horizontal deformation of the retaining wall. This study may provide reference for the maintenance and strengthening of reinforced retaining walls.