Performance of reinforced concrete elements subjected to extreme loads

极端荷载的出现越来越多，这些荷载表现出动态特征，如地震激励、海啸诱发的水动力和恶意爆炸荷载，已经使我们的基础设施、生命安全和经济稳定的威胁日益加剧。2005年7月7日发生在英国伦敦地铁系统的恐怖爆炸事件、2002年10月12日发生在印度尼西亚巴厘岛的恐怖爆炸事件、1995年4月19日发生在俄克拉荷马城的阿尔弗勒德·默拉大厦的恐怖爆炸事件、2004年亚洲海啸和2005年巴基斯坦地震等灾难性事件都表明，这些危险是不容易抑制的，并继续扰乱着社会对安全与保障的追求。反恐专家一致认为，加拿大成为恐怖活动的目标只是时间问题。然而，现代建筑规范明确地只提供了地震中由于地面震动而产生的力的指导方针，很少关注爆炸荷载对民用结构的作用以及水动力对海岸线结构的影响。这一建议是专门针对关键钢筋混凝土元件的性能受到恶意爆炸荷载。申请人在本构和非线性有限元建模以及极端载荷大规模测试方面的经验为本研究提供了专业知识。短期目标是：1。发展关键结构构件的能力关系，以评估给定爆炸事件的损伤，并确定渐进倒塌分析的剩余承载能力。2. 推进地震细节设计方法，以改善新建筑中关键元件的防爆设计，从而减轻渐进式倒塌造成的损害。3. 评估现有结构中关键部件的改造技术，以减轻爆炸危险并阻止渐进倒塌。

The increasing occurrence of extreme loads, those demonstrating dynamic characteristics such as earthquake excitations, tsunami-induced hydrodynamic forces, and maliciously-intended blast loading, has brought to the fore the escalating threat to our infrastructure, life safety, and economic stability.  The recent terrorist bombings of the London, England Subway System on July 7, 2005, the resort island of Bali, Indonesia on October 12, 2002, and the Alfred P. Murrah Building in Oklahoma City on April 19, 1995, and the catastrophic events of the Asian Tsunami of 2004, and the Pakistani Earthquake of 2005 have demonstrated that such hazards are not easily suppressed and continue to disturb society's quest for safety and security.  Terrorist experts agree that it is only a matter of time before Canada is targeted by terrorist activity.   Modern building codes, however, have explicitly only provided guidelines for the forces that arise due to the ground shaking experienced during an earthquake - little attention has been given to the actions of blast loading on civilian structures and the effects of hydrodynamic forces on shoreline structures.     This proposal is focused specifically to address the performance of critical reinforced concrete elements subjected to maliciously-intended blast loading.  The applicant's experience in constitutive and nonlinear finite element modeling and large-scale testing for extreme loads provides the expertise for this study. The short term objectives are: 1. To develop capacity relationships for critical structural elements to evaluate damage for a given blast event and determine residual load-bearing capacity for progressive collapse analysis. 2. To advance seismic detailing methodologies to improve blast-resistant design of critical elements in new construction, such that damage due to progressive collapse is mitigated. 3. To assess retrofit techniques for critical elements in existing structures to mitigate the blast hazard and impede progressive collapse.