铁路肋板式槽型连续梁剪力滞效用试验研究

Experimental Study on Shear Lag Effect of Railway Ribbed Trough Continuous Beam

铁路肋板式槽型连续梁是一种新结构,由腹板、肋板、底板和设置在支座处的横隔板组成。对沪通铁路黄封联络线(40+64+40)m肋板式槽型连续梁进行实桥静载试验研究,该试验是国内首次进行的大跨度槽型连续梁桥实桥试验。试验过程中分析了截面位置、肋板、支座等因素对槽型梁底板剪力滞效用的影响。试验结果表明:肋板式槽型梁在荷载作用下,截面底板存在较明显的剪力滞现象,不同截面位置剪力滞系数有差异;跨中无肋板截面在承受正弯矩作用时底板腹板位置呈现正剪力滞效用,在承受负弯矩作用时呈现负剪力滞效用;由于支座影响在承受负弯矩时底板腹板位置呈现正剪力滞效用,且剪力滞效用较其他截面明显;肋板会改变槽型梁截面正负剪力滞效用。

Railway ribbed trough continuous beam is a new structure composed of web plate,rib plate,bottom plate,and transverse partition plate set at the support.A static load test study was conducted on the(40+64+40)m ribbed slab continuous beam of the Huangfeng connecting line of the Shanghai-Nantong Railway.This test is the first large-scale trough continuous beam bridge test conducted in China.During the experiment,the influence of factors such as section position,rib plate,and support on the shear lag effect of the bottom plate of the trough beam was analyzed.The experimental results show that under load,there is a significant shear lag phenomenon in the bottom plate of the ribbed groove beam,and the shear lag coefficient varies at different section positions.The cross section without ribs exhibits a positive shear lag effect at the position of the bottom plate web when subjected to positive bending moment,and a negative shear lag effect when subjected to negative bending moment.Due to the influence of supports,the position of the bottom plate web plate exhibits a positive shear lag effect when bearing negative bending moments,and the shear lag effect is more obvious than other sections.The rib plate will change the positive and negative shear lag effect of the groove beam section.