摘要
为深入了解连续斜交梁桥的动力特性,以一座三跨连续斜交T梁桥为工程实例,建立了不同斜交角度的三跨连续斜交T梁桥的Midas Civil空间梁格模型,分析了斜交角的变化对结构的振型分布和自振频率的影响变化规律,并以斜交角作为影响因素,对现行《公路桥涵设计通用规范》中连续梁桥冲击系数计算采用的基频通用公式进行了修正.研究表明:三跨连续斜交T梁桥的竖弯振型分布在自然振型的不同阶数中,随着连续斜交梁桥斜交角度的增大,结构的弯扭效应变得更加明显,使得竖弯振型的分布也产生了变化;竖弯振型对应的自振频率均随斜交角的增加而增大,当斜交角度大于30°时,基频计算应计入斜交角影响;现场实桥动载试验表明本文提出的基频修正公式是比较合理的,对于此类结构的工程设计具有重要的参考价值.
Spatial beam lattice model of a three-span continuous skew T-beam bridge is built in Midas Civil to provide a deep understanding toward the dynamic characteristics of such structure, and the changing regulation of natural vibration frequency and vibration mode with different skew angles is analyzed. Based on current codes, a modified calculation formula of fundamental frequency is put forward to consider the effect of skew angle structure. The study shows that for threespan continuous skew bridge, the vertical bending vibration modes are distributed in different orders of natural vibration modes. With the increase of the skew angle of the continuous skew girder bridge, the affection of bending and torsion on the structure is more obvious, and the distribution of the vertical bending modes in the natural vibration modes is also changed.The vertical bending vibration frequency increases with the skew angle. When skew angle is greater than 30 degrees, the effect of skew angle on the calculation value of frequency should be considered. The rationality of the formula proved by this paper is verified by the field bridge dynamic loading test, and it will provide important references for the engineering design of such structure.
出处
《河北工业大学学报》
CAS
2017年第5期68-73,共6页
Journal of Hebei University of Technology
基金
天津市交通运输委员会科技发展计划(2016A-07)
廊坊市科技支撑计划(2016013073
2017013003)
关键词
三跨连续斜交T梁桥
斜交角
振型
自振频率
three span skew continuous T-beam bridge
skew angle
vibration mode
natural frequency
