中文摘要：

为了解混合梁斜拉桥中主梁钢-混结合段的力学行为,按照相似原则设计了厦门马新大桥主梁钢-混凝土结合段的缩尺试验模型,对试验模型分别按照设计荷载和1.7倍设计荷载进行加载,测试试验模型的控制断面和主要构件的应力、变形随加载历程的变化,并结合数值分析对钢-混结合段的传力机理进行研究.研究结果表明：结合段钢结构、混凝土结构及PBL键贯穿钢筋的应力水平较低,结合段具有较强的安全储备;钢箱与混凝土之间相对滑移量较小,钢箱与混凝土之间共同受力工作性能良好,钢结构荷载被比较顺畅地传递到混凝土结构;钢-混结合段传力构件荷载分配合理,设置PBL剪力键的有格室后承压板构造是一种合理的钢-混结合段结构形式.

英文摘要：

Based on the similarity principle,a reduced scale test model of steel-concrete joint section of The Xiamen Maxin Bridge is designed to investigate the mechanical behavior of steel-concrete joint section of hybrid beam cable-sayed bridges.The test model is loaded with design load and 1.7 times design load,and the variations of stress and deformation of control sections and main members with loading history are obtained.Combining test results with numerical simulation results,the load transfer mechanism of steel-concrete composite joint section is researched.As shown in the results,the stress of steel,concrete and PBL connector of the joint section is small,and there is enough safety capacity in the joint section.The relative slip between steel box and concrete is small,the steel box and concrete work together well,and the load from steel is smoothly delivered to concrete.The load distribution of load-transmission members is proper.It is proved by the test that the lattice with post-bearing plate and PBL shear connectors is reasonable for steel-concrete composite joint section.