强潮深海区钢栈桥结构动力响应

Structural Dynamic Response of Steel Trestle at Strong Tidal Deep Sea Region

大量采用贝雷桁架结构作为纵向承重梁的钢结构栈桥被广泛应用于跨海桥梁工程的施工过程中,为研究海洋环境与台风气候对钢栈桥结构强度与稳定性的影响,以宁上高速公路东吾洋特大桥钢栈桥工程为背景,针对强潮深海环境条件带来的挑战,结合实际工程条件,介绍了钢栈桥的结构特征,并通过建立有限元模型,在考虑水流力和台风影响的情况下,从力学性能上对钢栈桥的结构特性和承载能力进行了分析。研究结果表明,在水流力和风荷载综合作用下的各种工况之中,当履带吊在边跨跨中进行侧吊作业时或者在台风期,钢栈桥结构构件的正应力和剪应力易达到峰值;在贝雷梁和横向承重梁的支承处,贝雷梁桁架中的竖杆下端产生了应力集中现象。研究结果可为今后海洋环境下类似条件的贝雷钢栈桥的设计与研究提供参考。

A large number of steel structure trestles using Bailey truss structures as longitudinal load-bearing beams is widely used in cross-sea bridge construction.To study the influence of marine environment and typhoon climate on the structural strength and stability of steel trestles,take the steel trestle project of Dongwuyang Bridge on Ningde-Shangrao Expressway as the background.In view of the challenge brought by the deep sea environmental conditions of strong tide and combining with the actual engineering conditions,the structural characteristics of steel trestle were introduced.The finite element model was established.Considering the influence of water flow force and typhoon,the structural characteristics and bearing capacity of steel trestle were studied in terms of mechanical properties.The result indicates that under various working conditions with the combined action of water flow force and wind load,the positive and shear stresses in structural members of steel trestle bridge are prone to peak when the crane carries out side lifting operations in the side span or during typhoon periods.The stress concentration occurs at the lower end of vertical bar in the Bailey beam truss at the support of Bailey beam and the transverse load-bearing beam.The study results can provide reference for the design and research on Bailey steel trestle under similar conditions in marine environment in the future.