【作者】 李娜；

【导师】 袁卫宁；

【作者基本信息】 长安大学 ， 结构工程， 2010， 硕士

【摘要】 随着道路等级的不断提高和建设规模的扩大,桥梁呈现出跨径越来越大、桥型越来越丰富、结构越来越轻型化的发展趋势,钢-混凝土组合结构的发展为桥梁工程中一些技术难题的解决提供了全新的思路,成为桥梁结构体系的重要发展方向。由于我国目前尚无钢-混凝土组合梁桥设计方面的规范,因而此类研究具有重要的现实意义和参考价值。本文根据变截面梁桥的特点以及常用的曲线变化形式,分析了钢-混凝土组合箱梁的受力特性。采用sap2000有限元程序,结合实际工程中的三跨连续变截面钢-混凝土组合箱梁桥进行全桥建模,对变截面钢-混凝土组合箱梁桥在施工荷载作用下的抗弯、抗扭刚度、钢箱板件的应力、采用预压法为钢筋混凝土桥面板施加预应力的效果、桥中栓钉内力的分布规律、全桥在车道动荷载作用下的受力特性以及桥梁的预拱度设置等问题进行了研究,并得出了一些有用的结论。研究发现,变截面钢-混凝土组合箱梁桥在施工荷载作用下,抗弯、抗扭刚度均显著提高,钢箱各板件的应力明显减小,采用预压法为钢筋混凝土桥面板施加预应力的效果也更好,桥中栓钉的剪力也呈现出一定的分布规律；桥梁在车道动荷载作用下抗弯、抗扭刚度有所提高,桥面板单元所受的纵向弯矩和横向弯矩也有所减小。本文通过计算和分析后,给出了变截面梁桥栓钉内力设计值的建议值,并综合两个荷载工况的计算结果,给出了变截面梁桥预拱度的建议值。更多还原

【Abstract】 With the improvement of road level and the expansion of construction scale, bridges tend to have longer span, more colorful styles, and lighter weight of construction. The development of steel - concrete composite structure provides completely a new idea for the solution of some technical difficulties of bridge project, and becomes important development direction in the inovation of bridge-structures. Since so far China has no design specifications on steel - concrete composite bridges, the study on this area has great practical significance and reference value.Based on the characteristics of bridges with variable cross-section and its common style of variations, this paper analyzes the mechanical characteristic of steel - concrete composite box girders. Then a practical project of a three-span continuous steel - concrete composite box girder bridge with variable cross-section is modeled by using Sap2000 finite element software, and a study is conducted on some problems such as the flexural rigidity, the torsional rigidity, the plates’stresses, the effect of preloading the concrete bridge deck to prestress it, the distribution law of shear studs’internal force under construction load, and the mechanical characteristic under lane load, as well as the precamber of steel - concrete composite box girder bridge, with some useful conclusions summaried.It is found out that as compared with steel-concrete composite box girder bridge with constant cross-section under the construction load, the flexural rigidity and the torsional rigidity of such bridge with variable cross-section have been greatly improved, the plates’ stresses are significantly reduced, much better preloading effect by prestressing the concrete deck has been obtained, and the distribution of shear studs’internal force follows certain law. Under the lane load, it has higher flexural rigidity and the torsional rigidity, and smaller longitudinal moment and lateral moment of the deck element. From the calculation and analysis, the suggested coefficient of the shear studs’internal force and precamber were given.更多还原