车辆荷载作用下横梁非对称拼接的连续T梁桥受力特性分析

Stress Characteristics Analysis of Continuous T-Beam Bridge with Asymmetrically Spliced Beams Under Vehicle Load

为了避免对现有桥梁进行改扩建工程中出现新旧桥横梁位置相互错位问题,以横梁非对称拼接的连续T形拼宽梁桥为研究对象,采用midas Civil建立空间有限元模型,讨论拼接段横梁的合理拼接方式,分析车辆荷载作用下拼宽梁桥的受力特性及空间传力机理。研究结果表明:车辆荷载对不同拼接横隔梁形式桥梁的新、旧桥T梁受力影响较大。全拼接时9道横隔梁力的传递最为均匀。随着拼接处横隔梁数量从9片减少到7片和5片,横隔梁横桥向传力能力减弱,传递到非加载侧的荷载减小;非加载侧的T梁边跨、次边跨和中跨跨中截面弯矩和挠度减小。相较于采用9道横隔梁拼宽的T梁桥,采用7道横隔梁拼宽的T梁桥的弯矩和挠度变化幅度不大,变化幅度的平均值分别为3.59%和2.69%;采用5道横隔梁拼宽的T梁桥的应力和挠度变化幅度较大,变化幅度的平均值分别为16.96%和10.31%。当工期和经费受限时,可采用5道横隔梁的拼接方法。

In order to avoid the existing bridge in the reconstruction and expansion of the bridge occurred in the old and new crossbeam position of the problem of mutual dislocation,the continuous Tshaped splitwidth beam bridge with asymmetrical spliced beams is taken as the research object,midas Civil was used to establish a finite element model,the reasonable splicing mode of splicing section beams is discussed,the mechanical characteristics and spatial force transfer mechanism of splicing wide beam bridges under vehicle load are analyzed.The results show that vehicle load has a great influence on the stress of Tbeams of new and old bridges with different splicing girder types.As the number of beams at the splice is reduced from 9 to 7 and 5,the force transfer ability of the beams across the bridge is weakened,and the load transferred to the nonloading side is reduced.The bending moment and deflection of the Tbeam at the nonloaded side,the secondary side span and the middle span are reduced.The bending moment and deflection of Tbeam bridge with 7 transverse spacer beams vary little compared with the Tbeam bridge with 9 transverse spacer beams,and the average variation amplitude is 3.59%and 2.69%,respectively.The stress and deflection of the Tbeam bridge with 5 transverse separated beams have a large variation range,and the average variation amplitude is 16.96%and 10.31%respectively.When the time limit and funding,the use of 5 diaphragm splicing method.