客运专线96m下承式密布横梁体系钢桁简支结合梁桥模型试验研究

【作者】 侯杰平；

【导师】 吴斌； 叶梅新；

【作者基本信息】 中南大学 ， 结构工程， 2009， 硕士

【摘要】 客运专线和高速铁路行车速度快、密度大,对桥梁的抗弯刚度、抗扭刚度、稳定性和耐久性要求高,下承式密布横梁体系钢桁结合梁桥能较好地满足上述要求。本文对一座96m下承式密布横梁体系简支钢桁结合梁桥制作了1:6全桥缩尺模型,完成了有限元分析和三个阶段的模型试验,主要工作如下:1.对一座96m下承式密布横梁体系简支钢桁结合梁桥应用相似理论设计制作了1:6的全桥缩尺模型,设计制作了加载辅助装置,确定了试验加载方案。2.对纯钢模型、半结合模型和全结合模型完成了各个工况下的模型试验和有限元分析计算。模型结构位移、应力实测值与理论计算值吻合较好,在此基础上分析研究了桥梁结构的变形和受力状况。3.研究了混凝土桥面板对桥梁结构受力的影响。结果表明:混凝土桥面板提高了结构的整体刚度,改善了下弦杆和桥面系的受力;在96m下承式密布横梁体系简支钢桁结合梁桥体系中,混凝土板厚度宜取24cm～30cm。4.分析半结合模型、全结合模型的试验和计算结果得出结论:混凝土板与下弦杆结合,能够明显减小横梁端部的应力,对减小下弦杆的应力也起到了一定的作用,而对其他构件的受力影响不大。5.分析研究了密布横梁体系两种结合桥面的受力特性,结果表明:下弦杆除受轴力外,还受较大的竖向弯矩作用,其竖向弯矩的大小与节间小横梁和下弦杆的竖向抗弯刚度有关;桥面系参与主桁共同作用中,半结合模型约为26%～33%,全结合模型约为37%～42%。本文的研究成果为96m下承式密布横梁体系简支钢桁结合梁桥设计提供了依据,对其他类似结构也有参考价值。更多还原

【Abstract】 For reason of rapid and dense traveling, special line and high-speed railway have high requirements for the bridge in flexural rigidity, torsional rigidity, stability and durability. The deck-through steel truss-concrete deck composite bridge with multi-trtransverse-beams could meet the above mentioned requirements quitely. In this paper,on basis of a deck-through steel truss-concrete deck composite bridge spanning 96m with multi-trtransverse-beams, a 1:6 reduced-scale model was constructed and both experiment and finite element analysis of three model stages were completed. The main work has been done as follows:1. A 1:6 reduced-scale model was constructed according to the similarity theory, moreover the accessorial loading device was designed and fabricated, the loading project of the experiment was decided.2. Both experiment and finite element analysis of several various load cases were completed to the steel model structure,the semi-composite model structure and the completely-composite model structure respectively. The values of displacement and stress of the model experiment accords with those of the finite element analysis relevantly. By analysing the results of both experiment and finite element analysis, the deformation and the mechanical behavior of the three structures were studied.3. The influence of the concrete bridge deck on the mechanical behavior of the bridge was studied. The results show that the concrete bridge deck can enhance the integral rigidity of the structure, and improve the mechanical behavior of the bottom chord and the bridge deck system; for the deck-through steel truss-concrete deck composite bridge spanning 96m with multi-trtransverse-beams, the favorable thickness of the concrete deck is 24～30cm.4. By analysing the experiment results and the theoretical results of the semi-composite model structure and the completely-composite model structure, the compositing the concrete with the bottom chord can reduce the stress on the end of the transverse-beam evidently and which is also some effective on the bottom chord but little on others. 5. The mechanical behavior of the two types of the composite deck system of this kind of truss bridge was studied. The results show that the bottom chord endures vertically bending moment significantly besides axial force, the value of the vertically bending moment is related to the vertical rigidity of both internode-transverse beam and bottom chord. Secondly, the extent of deck system co-acting with the main truss is 26%～33% for the semi-composite model structure and 37%～42% for the completely-composite model structure respectively.The research results of the paper could supply the design consideration for the deck-through steel truss-concrete deck composite bridge spanning 96m with multi-trtransverse-beams and extently for other similar structures.更多还原