波形钢腹板组合箱梁翼板有效宽度取值问题的理论研究

发布时间：2018-03-23 06:35

本文选题：波形钢腹板组合箱梁　切入点：有效宽度　出处：《兰州交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：相比较传统的预应力混凝土箱梁,体外预应力波形钢腹板组合箱梁具有结构自重降低，同比减少25%～30%,结构抗震性能好、外型美观、节省建筑材料等诸多优点。因为波形钢腹板组合箱梁充分体现出了钢-混凝土组合梁的优点，尤其对于重荷、大跨度桥梁等要求梁截面高度低的桥梁更突显出它的优势。波形钢腹板组合箱梁具有较大的应用范围，适合在工程中较为普遍的推广和应用。对于波形钢腹板组合箱梁设计来说，合理确定混凝土翼板的有效宽度是十分关键的。它的取值直接影响到其承载力及挠度计算。由于混凝土翼缘上剪力滞的影响，纵向应力随着离梁肋的距离增加而减小。而现今的桥梁规范通常采用定义“有效宽度”来解决这个问题，从而填补了我国规范在计算箱梁翼缘有效宽度方面的空白，而且对有效宽度的使用环境进行了规定，对实际设计起到建设性作用。有效宽度的概念是针对受弯构件的受“压”翼缘提出的。承载能力极限状态对结构进行承载能力计算时，弯效应考虑有效宽度，压效应不考虑有效宽度。正常使用极限状态对结构的抗裂、裂缝宽度和挠度进行验算时不考虑有效宽度。使用阶段横截面混凝土法向压应力计算时，弯效应考虑有效宽度，压效应不考虑有效宽度。但是规范中对箱梁的翼板有效宽度取值是否同样适用于波形钢腹板这种特殊结构还有待考证。另外，影响有效宽度取值的因素诸多复杂，由于技术资金等方面的问题，，以前对波形钢腹板的有效宽度难以进行全面深入的精确研究。本文以静力试验研究为出发点，综合波形钢腹板组合箱梁的结构特征，通过观察并剖析模型在每个受力阶段的监测数据诸如变形性能、控制截面应变等，进而总结了波形钢腹板组合箱梁翼板的应力及应变分布特点。针对上述情况，正文采用有限元分析软件ANSYS数值模拟了模型的受力－变形始末，能够为深入分析提供依据。为了全面合理地分析不同参数对波形钢腹板组合箱梁混凝土翼板有效宽度的影响，本文确定了诸多不同波形钢腹板组合箱梁模型，以不同结构体系、荷载类型、箱梁几何参数的变化等指标为参数，以便较为系统地探讨有效宽度的取值问题。最后本文在比较规范对波形钢腹板组合箱梁有效翼缘宽度取值的基础上，根据有限元模拟分析的系列结果提出了在实际设计中采用现行桥规来计算波形钢腹板组合箱梁的混凝土翼缘有效分布宽度是偏于安全的，可供工程计算参考。
[Abstract]:Compared with the traditional prestressed concrete box girder, the external prestressed corrugated steel web composite box girder has the advantages of reduced structural weight, 25% less than the same number of years last year, good aseismic performance and beautiful appearance. Because the corrugated steel web composite box girder fully embodies the advantages of steel-concrete composite beam, especially for heavy load, The advantages of long-span bridges such as bridges with low cross-section height are highlighted. The composite box girders with corrugated steel webs have a wide range of applications and are suitable for popularization and application in engineering. For the design of composite box girder with corrugated steel webs, it is very important to reasonably determine the effective width of concrete flange. Its value directly affects the calculation of bearing capacity and deflection, because of the influence of shear lag on the flange of concrete. The longitudinal stress decreases with the increase of the distance from the beam rib. Nowadays, the bridge code usually uses the definition of "effective width" to solve this problem, thus filling the gap in the calculation of the effective width of the flange of box girder in our code. And the effective width of the use of the environment is specified, the actual design plays a constructive role. The concept of effective width is proposed for the "compressed" flange of a bending member. When calculating the bearing capacity of a structure under the ultimate state of bearing capacity, the effective width is considered in the bending effect. The effective width is not considered in the compression effect. The effective width is not considered when checking the crack width and deflection in the normal use limit state, and the effective width is taken into account in the normal compression stress calculation of the cross-section concrete in the use stage. The effective width is not considered in the compression effect. However, whether the effective width of the fender in the code is equally applicable to the special structure of the corrugated steel web is still to be verified. In addition, the factors affecting the effective width are complex. Due to technical problems, it is difficult to study the effective width of corrugated steel web. In this paper, based on the static test, the structural characteristics of the corrugated steel web composite box girder are synthesized, and the monitoring data of the model at each stress stage, such as deformation performance, control of cross-section strain, are observed and analyzed. Furthermore, the characteristics of stress and strain distribution of composite box girder with corrugated steel webs are summarized. In view of the above situation, the finite element analysis software ANSYS is used to simulate the stress and deformation of the model. In order to analyze the effect of different parameters on the effective width of concrete fender of composite box girder with corrugated steel webs, many models of composite box girder with different waveforms of steel webs are determined in this paper. The load type, the change of box girder geometric parameters and so on are parameters, so as to discuss the value of effective width systematically. Finally, on the basis of comparing the effective flange width of the corrugated steel web composite box girder, According to the series results of finite element simulation analysis, it is put forward that the effective distribution width of concrete flange of composite box girder with corrugated steel webs is safe in practical design, which can be used as a reference for engineering calculation.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.213

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