大型站房连续倒塌仿真分析

Simulation Analysis of Progressive Collapse for a Station

研究目的:大型交通枢纽的空间体量大、覆盖范围广,因而在遭遇偶然荷载作用并因局部失效诱致整体结构发生连续性倒塌时,会造成大量的人员伤亡和巨大的财产损失,应对其进行抗连续倒塌分析。为研究结构连续倒塌的全过程,采用瞬时加载法和大变形动力有限元软件LS-DYNA,对某大型站房进行2个单柱失效和1个双柱失效情况下的结构连续倒塌分析,构件破坏判断标准参考美国国防部规范UFC 4-023-03的要求。研究结论:分析结果表明:(1)在不同位置单柱失效情况下,该站房结构发生了局部破坏,但破坏限制在去除构件周围的一定范围内;(2)在双柱失效情况下,结构破坏范围明显加大,但最终破坏仍限制在局部范围内,不会造成整体结构的连续坍塌,结构具有较强的抗连续倒塌能力;(3)对于钢结构,提高材料的失效应变可以显著提高结构抵抗连续倒塌的能力;(4)该研究成果可为类似结构的安全性评价提供一种简便的尺度。

Research purposes： Communication Junction has intensive people and it is very possible to be attacked, so it is necessary to proceed progressive collapse analysis. To study the progressive collapse process of structures, a method to apply instantaneous load was adopted to simulate the progressive collapse of a station with a failed middle column at the first story by using the large deformation and dynamic finite element software LS - DYNA. Two cases of single - column failure and one case of double - columns failure were analyzed employing alternative path method according to the requirements of UFC 4 - 023 - 03. Research conclusions： （ 1 ） This station is locally damaged for single - column failure cases, but the damage is confined within the limited area around the removed member. （ 2 ） For the double - columns failure case, the damaged area is obviously increased, but it is still confined in a limited area and will not induce the whole structure. （3）The progressive collapse resisting capacity of steel structures can be remarkably improved by increasing the failure strain of the structural material. The structure has strong ability to resist progressive collapse. （4）The research results can provide a simple measure to evaluate the safety performance for such structure.