中文摘要：

中山一桥是由一片中拱肋，两片边拱肋以及两片座拱肋组成的一种新型空间组合钢拱桥，该桥造型新颖独特，在国内外应用尚属首次。考虑到该桥细部构造在力的传递方面起关键作用，并且纵梁梁截面形式为挑臂较大的单箱双室箱形结构，所以基于1：10全桥试验模型，对中拱→座拱→边拱横梁结点、边拱和边拱横梁结点的细部构造以及纵向箱梁的剪力滞效应进行了试验研究，同时建立了空间三维全桥板壳模型用来校核试验结果、指导模型试验加载。通过试验结果与理论结果的比较可以看出二者基本吻合，试验和理论结果均表明在最不利荷载作用下该桥最大应力远小于设计容许值由此证明该桥细部构造设计是合理安全的。进一步的研究表明，在恒载作用下该桥纵梁的剪力滞效应受横梁、轴力的影响很大。

英文摘要：

The First Zhongshan Bridge is a new type space - combined tied arch bridge composed of one middle arch rib, two side arch ribs and two seat arch ribs. The structure of the bridge is innovative and special, and almost no similar design can be found at present. Considering the detail constructions of the bridge play an important role in the load transferring, and： the longitudinal girders of the bridge are in a form of box shape with a wide upper flange, based on a 1/10 - scale model test a significant study on middle arch→seat arch →side arch cross beam joints, side arch→side arch cross beam joints and the shear lag effect of the longitudinal box girders were carried out. A 3D shell finite element model of the model bridge was developed and finite element analysis was performed to obtain the theoretic results, then to predict the structural behavior and guide the test loading. By comparison of the test results with the theoretical ones, the values were in good agreement, and the maximum stress under the extreme load were all far below the allowable values, thus the detail constructions Of the bridge were proved reasonable and safe. Further study indicated that cross beams and axial forces have great influence to the shear lag effect of lonagitudinal box girders under full dead load.