Collaborative Research: Fire Damage Mitigation and Post-Fire Evaluation of Steel Girder Bridges

这个合作研究项目的总体目标是通过对钢梁桥系统在火灾中的性能有一个基本的了解，开发一种合理的方法来进行桥梁火灾安全评估。近年来，人们对桥梁火灾隐患的关注越来越多。由于钢材在高温下失去强度和刚度，钢桥很容易受到火灾的破坏，甚至倒塌。具体目标是：(1)确定在火灾中影响桥梁易损性的参数；(2)推荐减轻火灾破坏性影响的方法；(3)制定基于火灾风险的定性分类策略；(4)确定火灾后的剩余强度。实验和数值研究将通过普林斯顿大学和密歇根州立大学的合作进行。这项研究将发展推进桥梁消防安全规定所必需的基础知识，并将发展实践工程师在桥梁火灾事件发生后需要快速做出明智决策的实用知识。当局将制订指引，以减轻因火灾而引致钢桥倒塌的情况。指引的制订可望带来最佳及消防安全的设计，这些设计不但经济，而且以合理的设计原则为基础。目前，桥梁设计法规对如何针对地震等荷载进行设计提供了详细的规范，但关于如何在严重火灾情况下设计桥梁的信息相对较少。这项研究将成为制定设计指南的基础，以提供更好的消防安全，并有助于美国处理桥梁火灾危险的规范和标准的制定。PIS将通过出版物和在研讨会和会议上的演讲向执业工程师传播这项工作。该项目还将通过参与该项目的研究活动，为研究生提供有关火灾对建筑物影响的高级培训。

The overall objective of this collaborative research project is to develop a rational approach to bridge fire safety assessment by developing a fundamental understanding of the performance of steel girder bridge systems when exposed to fire. In recent years there has been a growing concern regarding fire hazard in bridges. Steel bridges are highly susceptible to fire induced damage and even collapse, since steel loses its strength and stiffness at high temperatures. The specific objectives are to (1) determine the parameters that affect the bridge vulnerability in a fire, (2) recommend means for mitigating the destructive effects of fire, (3) develop a qualitative strategy for classifying bridges based on fire risk, and (4) determine the post-fire residual strength. Experimental and numerical studies will be performed through collaboration between Princeton University and Michigan State University. This research will develop fundamental knowledge that is necessary to move forward with bridge fire safety provisions, and it will develop practical knowledge that practicing engineers need to make fast informed decisions after a bridge fire event. Guidelines will be developed for mitigating fire-induced collapse in steel bridge girders.The guidelines developed are expected to lead to optimum and fire safe designs that are not only economical but are also based on rational design principles. Currently, bridge design regulations provide detailed specifications about how to design for loads such as earthquakes, but relatively much less information is available on how to design a bridge for a severe fire. This research will form the basis for developing design guidelines to provide improved fire safety and contribute to the development of US codes and standards dealing with the fire hazard in bridge girders. The PIs will disseminate this work to practicing engineers though publications and presentations at seminars and conferences. The project will also provide advanced training to graduate students on the topic of fire effects on structures through their involvement in the research activities of this project.