斜靠式拱桥力学性能分析

Analysis of Mechanical Properties of Leaning Arch Bridge

以有限元为理论基础,以数值模拟为计算手段,对斜靠式拱桥静力、屈曲、动力特性和反应谱作用等方面进行了分析。拱桥在自重和车道荷载作用下,主拱轴力符合一般拱桥力学概念,斜靠拱受到主拱作用,在拱顶轴力最大。在恒载和使用荷载作用下,拱桥纵向和横向稳定系数值都大于5,满足拱桥稳定性要求。动力特性分析表明,相对于纵向刚度,横向刚度较弱,故在设计和施工中需注意主拱与稳定拱上部连接可靠、变形协调、空间受力一致。斜靠式拱桥在空间三个方向反应谱作用下,主拱在竖向激励下轴力最大,稳定拱为在竖向和横向激励下最大。纵观不同方向作用,纵向刚度较大,而地震作用较小。综合不同方向地震作用,主拱和稳定拱轴力分布规律大致类似于静力作用效果。

With the finite element as the theoretical basis,numerical simulation for calculating means,leaning arch bridge static,buckling,dynamic characteristics and the role of response spectra are analyzed.Arch bridge in the dead load and lane loads,the main arch axial force is in line with the general concept of arch bridge mechanic property.Leaning arch effect in the vault under the main arch,the largest axial force is occured.In the dead load and the use of loads,the arch vertical and horizontal stability coefficient is greater than 5,to meet the arch stability requirements.Dynamic characteristic analysis shows that relative to the vertical stiffness,lateral stiffness is weak,so in the design and construction should pay attention to the main arches and stability of the arch connecting the upper part of a reliable,deformation coordinate,space force in line.Leaning arch bridge in the space under the action of response spectra in three directions,the main arch in the vertical excitation is maximum axial force,stable arch in the vertical and horizontal excitation maximum.Looking at the role of different directions,the vertical stiffness of large,whereas the role of small earthquakes.Comprehensive seismic different directions,the main arch and stability in the arch axial force distribution is roughly similar to the effect of static roles.