混合梁结合部受力机理模型试验研究

Model Test and Mechanical Behavior Analysis of Steel-concrete Joint of Hybrid Girder

为揭示混合梁结合部的承载性能、破坏形态和受力机理,以主跨为818m的九江长江公路大桥为研究背景,选取混合梁压剪式结合部典型格室,并设计进行比较的承剪式结合部格室,开展了两个缩尺比为1∶2的结合部局部模型承载性能试验,测试了钢与混凝土的应变及相对滑移。研究结果表明:压剪式结合部承载能力是承剪式的两倍;压剪式结合部承压板传力约占总轴力的62.5%,承压板传力减小了钢格室应力,限制了钢-混凝土间相对滑移,降低了连接件传力比例,使结合部受力更合理。

To study the bearing behavior ,failure mode and mechanical behavior of different structural forms of steel‐concrete joint of hybrid girder ,based on the hybrid girder of Jiujiang Yangtze River Highway Bridge with 818‐metre main 8pan ,select a pressure‐resistant shear‐transferred steel‐concrete joint ,redesign a shear‐transferred only joint for contrast ,carry out two scale 1：2 model specimens bearing behavior experiment ,measure the strain and relative slip of steel and concrete .The results show that ：the bearing capacity of the pressure‐resistant shear‐transferred specimen is twice than the other ;the bearing plate carries about 62.5% of the axial load ,the force transmission of the bearing plate reduces the steel stress、steel‐concrete relative slip and the force transmission ratio of connectors , makes the load transferred more effectively .