斜交空心板桥拼宽结构承载力试验研究

以凤山分离立交大桥拼宽结构1∶6.05比例模型为例,进行斜交空心板梁桥拼宽结构静载全过程试验研究,并结合有限元分析斜交空心板梁桥拼宽结构的极限承载力和破坏机理.研究表明:在中跨跨中对称荷载作用下,跨中纵向接缝破坏主要由弯拉作用引起,支座位置处的纵向接缝破坏主要由接缝两侧位移差产生的剪切力引起,在边跨靠近内支承侧的钝角处容易产生平行于钝角角平分线的裂缝.有限元模拟基本反映了斜交空心板梁桥拓宽改造的特点,模拟结果与试验结果的破坏形态大致相同,极限承载力大小相近.

Research on bearing capacity of skewed hollow slab bridge after widening based on model test

The whole process of static test of a 1:6.05 scaled skewed model bridge after widening is introduced as the engineering background of Fengshan separation inter-change bridge. The testing results were compared and analyzed with those from nonlinear finite element calculation, and the study focuses on the failure mechanism and ultimate load-carrying capacity. The damage of the longitudinal joint near midspan is mainly caused by flexure and tension in action of symetrical concentrated load in the middle of the mid-span, while which is caused mainly by shear displacement near the bearing. in addition, cracks is easy to appear along the obtuse angle bisector near the inner bearings, so the reinforcement should be enhanced. The failure mode and the ultimate load-carrying capacity of element analysis are close to the testing results, which reflect the mechanical properties for the widened structure of skewed hollow slab bridge.