螺旋状山形钢管人行桥方案比较

Comparison of schemes for a steel pipe pedestrian bridge with spirally mountainous shape

主要介绍了某螺旋管状山形钢结构人行桥的初步设计方案比选.方案设计表明:螺旋管状布置与独立成环的管状布置相比受力更加合理,与独立成环并顶部增加刚性杆连接结构相比造型更加美观.对人行桥结构体系衍化过程、支座设置、力学性能进行了分析,结果表明:螺旋结构顶部一般无平面外支撑,故多为平面外变形控制;多榀螺旋结构和单榀螺旋相比具有一定弹簧效应,多榀螺旋的底部钢梁可以平衡相邻螺旋结构的弯矩,减小结构变形,对结构有利,与平面圆环结构相比螺旋结构能更好地利用截面的抗弯和抗扭性能.

This paper discusses several preliminary design schemes of a spiral tubular steel structure pedestrian bridge. The spiral tubular structure is more reasonable than the ring structure, and more beautiful than the ring structure with rigid rod at the top. The evolution process of system constitution, abutments and mechanical properties of the spiral tubular bridge steel structure are analyzed. Analysis results show that the top of spiral structure which has no out-of-plane supports, is mostly controlled by out-of-plane deformation. Compared with single spiral steel structure, multiple spiral has some spring effects, and the bottom steel beam balance the bending moment of adjacent members and reduce the structural deformation, the bottom steel beams are beneficial to the structure. The bending and torsion resistances of sections in spiral structure are better than those in ring structure.