90m钢桁架桥杆件失效影响计算分析——以万安县二线船闸工程为例

Calculation and Analysis of Member Failure Influence of 90 m Steel Truss Bridge——Taking the Second-line Ship Lock Project in Wan’an County as an Example

下承式钢桁架桥具有自重轻、跨越能力强的优点,同时可在自动化工厂进行焊接组装,运到现场直接拼装,有效缩短了施工工期,非常适合有航道需求的河流。但也因为钢桁架桥由细长构件组成,因此对钢材抗疲劳的要求较高,一旦部分构件发生疲劳破坏,或者受到撞击失稳破坏,将对结构体产生较大的不利影响。文章以江西省吉安市万安县二线船闸工程为研究背景,利用Midas Civil软件建立空间模型对发生杆件失效的钢桁架桥梁进行模拟分析,研究发生杆件失效后钢桁架桥下弦杆应力应变状态,研究成果可为桁架桥后续运营阶段维修提供依据和参考。

The through steel truss bridge has the advantages of light weight and strong spanning capacity. At the same time,it can be welded and assembled in the automated factory and transported to the site for direct assembly, which effectively shortens the construction period and is very suitable for rivers with waterway requirements. However, because the steel truss bridge is composed of slender components,the requirements for steel fatigue resistance are higher.Once some components are damaged by fatigue or impact instability, the structure will be greatly adversely affected.Taking the second-line ship lock project in Wan’an County,Ji’an City, Jiangxi Province as the research background, this paper uses Midas Civil software to establish a space model to simulate and analyze the steel truss bridge with member failure, and studies the stress and strain state of the lower chord member of the steel truss bridge after member failure.The research results can provide basis and reference for the maintenance of the truss bridge in the subsequent operation stage.