某过江提水工程160m三角桁式拱管桥设计分析

Design and Analysis of 160m Triangular Truss Arch Pipe Bridge for a River Crossing Water Lifting Project

为协调跨江管道桥兼具景观、通航等需求,某过江提水工程管道桥采用截面为正三角形三肢钢管桁架结构,一跨过江。全桥计算跨径160 m,矢高25 m,矢跨比1/6.4,拱肋截面采用3根Ф1000 mm钢管组成,壁厚24 mm。弦杆间的连接腹杆钢管外径均为400 mm,壁厚16 mm。在拱脚4 m范围内采用外包混凝土形式,钢管外20 cm等间距布置剪力钉,并配抗裂钢筋,厚度450 mm。拱座采用圬工混凝土扩大基础,拱座基础以中风化基岩为持力层。采用空间有限元程序MIDAS/Civil对拱管桥进行计算,结果表明,主拱结构强度、稳定性,K型节点和焊缝强度,基础抗滑、抗倾覆计算均满足规范要求。目前,拱管桥运营状况良好,达到预期目标,可为今后过江管道桥设计提供参考。

A River Pipeline Bridge has the needs of both landscape and navigation.The arch pipe is used to cross the river in one span,and the section is an equilateral triangle steel tubular truss structure.The calculated span of the bridge is 160m,the rise height is 25m,the rise span ratio is 1/6.4,and the arch rib section is 3 steel pipe with diameter of 1000mm and thickness of 24mm.The outer diameter of connecting web steel pipes between chords is 400mm,and the thickness is 16mm.Concrete shall be wrapped within 4m of the arch abutment.Shear nails shall be arranged at equal intervals 20cm outside the steel pipe,and crack resistant reinforcement shall be provided,with thickness of 450mm.Masonry concrete expansion foundation is adopted for the arch pedestal,and the moderately weathered bedrock is used as the bearing stratum.The spatial finite element program MIDAS/Civil is used to calculate the structural static force of the bridge.The results show that the strength and stability of the main arch structure,the strength of K-joints and welds,and the anti sliding and anti overturning calculation of the foundation meet the specification requirements.At present,the bridge is in favorable operation and has reached the expected goal,which can provide reference for the design of river crossing pipeline bridges in the future.