客运专线连续箱梁竖向温差取值探讨

为研究客运专线箱梁竖向温差荷载对结构受力的影响,对比分析美国、英国、日本及中国四种不同桥梁规范给定的非线性日照温度曲线,结合3跨变截面连续箱梁实例,计算不同桥梁规范非线性日照温度下结构截面的温度应力,表明我国铁路规范规定的温差荷载对结构使用阶段受力影响相对较大。结合我国客运专线桥梁结构实际情况,考虑桥面轨道结构对桥面温差的折减效应,提出我国客运专线箱梁桥竖向温差选取的建议。

Approach to Vertical Temperature Difference Value for Continuous Box Girders on Passenger Dedicated Lines

To understand the impact of the vertical temperature difference load of box girders on passenger dedicated lines on the structure,four distinct bridge specifications from United States,United Kingdom,Japan and China are compared and analyzed in terms of nonlinear sunshine temperature curve,and the temperature stress of the structure section at different nonlinear sunshine temperatures is calculated respectively for different specifications with reference to 3-span variable cross-section continuous box beam. The results show that temperature difference load as stipulated in Chinese specification brings about more effect on the structure. In view of the actual conditions of the bridges on dedicated passenger lines,and reduction effects of track structure on bridge deck temperature,the selection of vertical temperature differences of box girder bridges on passenger dedicated lines is recommended.