多室宽箱梁横向分布计算方法研究

发布时间：2018-05-03 14:34

本文选题：单箱多室 + 宽箱梁　；参考：《重庆交通大学》2014年硕士论文

【摘要】：随着道路路幅宽度日益加大，桥梁宽度也随之增大，在城市的中小跨径桥梁中，单箱多室截面的箱梁桥使用越来越多。此类桥梁截面特点是腹板间距小，但是箱室数量较多，结构的受力性能及特点较为复杂，没有专门针对单箱多室宽箱梁的实用计算方法。目前在多室宽箱梁中使用较多的方法为梁格法和横向分布法。研究显示梁格法在多室宽箱梁中的使用情况较好，但横向分布法会产生较大误差，因此有必要对现有的荷载横向分布计算方法进行改进，，使其适合单箱多室宽箱梁的横向分布计算。首先，利用通用有限元软件分析了多室宽箱梁的弯扭受力特性。以不同箱室数量、不同宽跨比的单箱多室悬臂宽箱梁为例，分别建立了扭转荷载和偏心荷载作用下的实体有限元模型，比较分析了箱室剪力流分布和横截面竖向位移沿横向的分布情况，结果表明扭转荷载作用下的剪力流分布与单箱单室箱梁或宽跨比较小的普通多室箱梁基本一致，偏心荷载作用下的剪力流分布主要由扭转剪力流和弯曲剪力流组成，因此偏心荷载作用下的计算分析可由整体竖向位移和整体扭转两部分效应分别计算叠加。其次，在计算多梁式桥梁横向分布系数刚接梁法的基础上，提出适用于多室宽箱梁空间实用计算方法的修正刚接梁法。将箱梁沿腹板间的顶底板切开成各片工字梁组成的结构，切口处以赘余力代替，建立力法方程组通过求解矩阵方程即可得出所有赘余力。介于刚接梁法求解过程较为繁琐，本文编写了赘余力求解程序，并提出了修正刚接梁法计算步骤及要点。最后，通过计算实例，建立有限元实体单元模型，验证本文所推导的修正刚接梁法，讨论了其适用性和精确性。此方法具有较好的实际应用价值，对单箱多室宽箱梁的计算有一定的帮助，也为后续深入研究提供依据。
[Abstract]:With the increasing road width, the bridge width is also increasing. In the medium and small span bridges in the city, the box girder bridge with single box and multi-room section is used more and more. The cross-section of this kind of bridge is characterized by small web spacing, but the number of box chambers is large, and the mechanical properties and characteristics of the structure are more complicated. There is no practical calculation method for single box and multi-chamber wide box girder. At present, many methods are used in multi-chamber wide box girder such as beam lattice method and transverse distribution method. The research shows that the beam lattice method is in good use in the multi-chamber wide box girder, but the transverse distribution method will cause great errors, so it is necessary to improve the existing calculation method of transverse distribution of load. It is suitable for the calculation of transverse distribution of single box and multi-chamber wide box girder. Firstly, the bending and torsional behavior of multi-chamber wide box girder is analyzed by using the general finite element software. The solid finite element models of a single box multi-chamber cantilever wide box girder with different number of chambers and different width-span ratios are established under torsional load and eccentric load respectively. The shear flow distribution of the box chamber and the vertical displacement of the cross section along the transverse direction are compared and analyzed. The results show that the shear flow distribution under the torsional load is basically the same as that of the single box girder or the common multi-chamber box girder with small width span. The distribution of shear flow under eccentric load is mainly composed of torsional shear flow and bending shear flow, so the calculation and analysis under eccentric load can be calculated and superimposed by the integral vertical displacement and the global torsional effect respectively. Secondly, on the basis of calculating the transverse distribution coefficient of multi-beam bridges, a modified rigid-connected beam method is proposed, which is suitable for the spatial calculation of multi-chamber wide box girder. The box girder is cut along the top and bottom plate between the web plates into a structure composed of each I-beam, and the incision is replaced by Yu Li. The equations of force method can be obtained by solving the matrix equation. In view of the complicated process of solving the rigid-connected beam method, this paper compiles the residual solution program, and puts forward the calculation steps and key points of the modified rigid-connected beam method. Finally, a finite element solid element model is established to verify the modified rigid beam method derived in this paper, and its applicability and accuracy are discussed. This method has good practical application value, which is helpful to the calculation of single box and multi-chamber wide box girder, and also provides the basis for further research.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.213;U441

【参考文献】