中文摘要：

斜拉桥钢-混凝土结合主梁的受力特点与常规结合梁有所不同。针对江津观音岩长江大桥钢-混凝土结合梁,设计并制作了1∶2大比例试验模型,对其进行了单项荷载与承载力极限状态荷载组合的加载试验,测试了试验模型主要断面的应变分布情况;结合有限元分析,对斜拉桥钢-混凝土结合梁的受力性能进行了研究。结果表明：斜拉桥结合梁承受较大弯矩时,截面上的应变并非线性分布,不满足平截面假定;轴力作用的加入能够有效抑制斜拉桥结合梁在弯矩作用下的滑移趋势,相比于常规结合梁,其钢与混凝土交界面的相对滑移量会更小;有限元分析结果与模型试验结果吻合较好,具有足够的工程精度;在该文所研究的斜拉桥主梁中,轴力主要由混凝土板承担,弯矩主要由钢梁承担。

英文摘要：

The mechanical behavior of the steel-concrete composite beam of a cable-stayed bridge is different from that of conventional composite beams. A segment model with an enlarged scale of 1：2 was designed and established based on the real steel-concrete composite beam of Guanyinyan Yangtze River Bridge. The test for both individual load case and combined load case of an ultimate limit state were carried out to obtain the distribution of the stress and deformation of key sections. The mechanical behavior of the steel-concrete composite beam was also studied by finite element analysis. The results show that when the composite beam is subject to a large bending moment the strain distribution of the cross section is nonlinear, implying that the plane section assumption is not suitable in this case. The relative slippage between a steel beam and a concrete slab caused by the bending moment can be significantly reduced by the axial force, which is much smaller compared with the common composite beams. The finite analysis results match well with the results by the model test and meet the engineering requirements as well. The majority of the axial force is bom by concrete slabs, while the moment is mainly undertaken by steel girders.