千米跨度公铁两用钢桁梁斜拉桥几何非线性研究  

Study of Geometric Nonlinearity of Rail-cum-Road Steel Truss Girder Cable-Stayed Bridge with Span Length over 1000 M

作　　者：张敏[1] 高宗余[1] 陈佳[1] 马润平[1] 

机构地区：[1]中铁大桥勘测设计院集团有限公司,湖北武汉430056

出　　处：《桥梁建设》2014年第5期15-20,共6页Bridge Construction

摘　　要：为研究非线性因素对超大跨度公铁两用斜拉桥主要构件变形和受力的影响程度,采用5种分析状态,对一座跨度超过千米的公铁两用钢桁梁斜拉桥进行成桥状态下的活载非线性计算分析。建立全桥平面杆系模型,计算各控制量在最不利活载作用下的极值及非线性影响系数。结果表明:对超大跨度公铁两用斜拉桥而言,斜拉索的垂度效应仍然是几何非线性影响的主要因素,梁-柱效应和大位移效应相对较弱;目前桥梁设计的通常方法是考虑修正斜拉索弹性模量进行线性计算,并在此基础上活载考虑10%的非线性放大系数,该方法现实、合理而且稍偏安全。To study the degree of influence of the nonlinear factors on the deformation and force conditions of the major components of super long span rail-cum-road cable-stayed bridge, 5 analysis state were used to calculate and analyze the live load nonlinearity of the completion state of a rail-cure-road steel truss girder cable-stayed bridge with span length over 1 000 m. The plane link model was established for the whole bridge of the truss girder cable-stayed bridge and the ul- timate values and nonlinear influential coefficients of the different control amounts under the worst live load were calculated. The results of calculation and analysis demonstrate that for the super long span rail-cum-road cable-stayed bridge, the stay cable sagging effect is still the major factor of the geometric nonlinear influence while the beam-column effect and the large displace- ment effect are relatively weak. In the current design of the cable-stayed bridge, the prevailing method is to calculate the linearity by considering the modifying of the elastic modulus of the stay cables and on the basis of which, 10% nonlinearity amplifying coefficient for the live load is also considered. The method herewith is realistic, reasonable and is somewhat safe.

关 键 词：斜拉桥 公路铁路两用桥 千米跨度 几何非线性 垂度效应 梁-柱效应 大位移效应 弹性模量 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]