叠合系杆拱桥主拱的内力分析

Mechanical Performance Analysis of Main Arches in Stacked Arch Bridges

结合一钢管混凝土叠合系杆拱桥方案,考虑在汽车荷载、支座位移以及混凝土徐变发生的几种工况下,运用有限元程序对其主拱的内力、变形进行了计算与分析,并与相应的哑铃型拱进行比较.给出上、下拱肋为不同矢跨比情况下的主拱拱脚截面内力,当叠合拱桥的上、下拱肋矢跨比分别采用1/5、1/4与矢跨比为1/5的哑铃拱拱肋的内力和主梁及拱顶变形计算结果.经过分析比较,叠合拱较哑铃型拱从结构刚度、内力等方面均得到了较好的改善,使结构从受力方面更容易满足工程设计的需要.

According to a design scheme of a stacked concrete-filled steel tabular tied arch bridge, considering of vehicle load, bearing displacement and several working conditions of concrete creeping, the internal force and deformation of main arches are calculated and analyzed in finite element program, and compared with the kind of dumb-bell section. The internal forces of the main arch springers are calculated in different rise-span ratios of top and bottom arch ribs. The internal forces of arch ribs and deformations of main spans are calculated in 1/5,1/4 rise-span ratios of top and bottom stacked arch ribs and in 1/5 rise-span ratio of dumb-bell arch ribs. After comparing, stacked arch is improved that the stiffness and internal force of the structure have been getting better, the mechanical property and stability of stacked arch bridges easily satisfy to the need of structure design.