加筋土桥台承载性能及影响因素的模型试验研究

Model Experimental Study on Load-bearing Performance and Influencing Factors of Reinforced Soil Abutment

摘要:

作为承载桥梁的下部结构，加筋土桥台的承载性能及影响因素历来备受关注。以桐岳高速公路上某加筋土桥台为原型，完成了4组大比例加筋土桥台的缩尺模型试验，研究了加筋间距、筋材与砌块面板连接形式、填料级配3个因素对桥台承载性能与变形特征的影响。试验结果表明：加筋间距和填料级配（包括最大粒径）是加筋土桥台承载性能的重要影响因素，筋材与砌块面板连接方式（强度）对加筋土桥台变形控制的作用不可忽视。减小加筋间距和改善填料级配，可提升加筋土复合体的整体刚度，减少桥台变形，增强桥台的承载性能；相较于筋材与砌块面板的摩擦连接，机械连接限制了两者的相对位移，增强了加筋土复合体的侧向约束，对减小桥台变形效果显著。

Abstract:

As the substructure of load-bearing bridge， the load-bearing performance of reinforced soil flexible abutment and its influencing factors have always been concerned. In this paper， a reinforced soil abutment on Tongyue Expressway is taken as a prototype， and four large scale model tests of reinforced soil abutment are completed. The effects of reinforcement spacing， the connection form between reinforcement and block panel， and the backfill gradation on the loading-bearing performance and deformation characteristics of the abutment are studied. The test results show that the reinforcement spacing and backfill gradation （including the maximum particle size） are important factors affecting the load-bearing capacity of reinforced soil abutment， and the connection form （strength） between reinforcement and block panel has an important effect on the deformation control of reinforced soil abutment. Reducing the reinforcement spacing and improving the backfill gradation can increase the overall stiffness of the reinforced soil composite， reduce the deformation of the abutment， and enhance the load-bearing capacity of the abutment. Compared with the friction connection between reinforcement and block panel， the mechanical connection limits the relative displacement of the reinforcement from block panel， and enhances the lateral constraint of the reinforced soil composite， reducing the deformation of the abutment.