摘要
采用空间有限元方法对刚性悬索加劲钢桁梁桥的施工全过程进行了仿真分析,通过变化边界条件与施加节点强制位移分别模拟结构体系转换和内力调整,采用释放纵梁一端的纵向刚度来模拟纵梁长圆孔的影响,对比了6种主要工况下结构的内力和位移。分析结果表明:通过体系转化和内力调整,能有效地使刚性悬索与钢桁梁共同受力;横、纵向内力调整能使结构的中边桁与中边跨的内力差异减小到5%以内;在纵梁两端设置长圆孔能有效避免其过早参与纵向受力,仅使整体结构的内力与挠度增加10%左右,但使得纵梁与横梁的最大组合压应力分别从-271.1-、505.8 MPa降低到-63.0、-178.0 MPa,小于材料的容许应力210 MPa。
3D finite element numerical method was used to simulate the whole construction processes of steel truss bridge stiffened with rigid cables. Changing boundary conditions and imposing compulsory displacements on some nodes were applied to simulate system transformation and internal force adjustment respectively. Relaxing the longitudinal stiffness of an end of longitudinal girder was applied to simulate the effect of slotted holes. The internal forces and deflections were compared under six main conditions. Analysis result shows that rigid cables can participate in action with steel trusses more effectively through system transformation and internal force adjustment. Through internal force adjustment in longitudinal and lateral directions, the deviations of internal forces for the chords of middle truss and side truss, as well as that of midspan and sidespan, are less than 5%. Slotted holes set at both ends of longitudinal girder can avoid it taking part in longitudinal action prematurely, through which the internal force and deflection of main truss would increase by about 10%, while the maximum combined compressive stresses of longitudinal girder and floor beam would decline respectively from -271.1 MPa and -505.8 MPa to -63.0 MPa and -178.0 MPa, which are less than their allowable stress value 210 MPa. 26 figs, 12 refs
出处
《交通运输工程学报》
EI
CSCD
北大核心
2009年第3期1-10,共10页
Journal of Traffic and Transportation Engineering
基金
NewCentury Excellent Talents in University(NCET-06-0855)
Science and Technology Project of West Traffic Construction of China(2006 318 812 112)
Science and Technology Project of Department of Communications of Guangdong Province(2007-15)
关键词
桥梁工程
刚性悬索
钢桁梁
体系转换
内力调整
bridge engineering
rigid cable
steel truss
system transformation
internal force adjustment
