Seismic Design and Evaluation of Concrete Bridges and Buildings

研究计划涉及两个主要领域，包括两个地震工程项目和两个混凝土基础设施性能项目。将对桥梁的抗震性能进行研究，以评估2014年加拿大公路桥梁设计规范中新制定的抗震设计条款。将开发预测桥梁柱在不同地震级别下的破坏程度的方法，以协助桥梁设计者实施新的基于性能的设计程序。目标是提供一种设计方法，不仅关注防止倒塌，而且最大限度地减少较小，更频繁的地震事件的损害。开展反循环加载试验，研究既有缺陷桥梁结构损伤指标的预测方法，开发预测可能损伤程度的分析工具。这项发现拨款旨在提高在适当的地震设计程序可用之前设计的旧桥梁的安全性，并将提供对不同级别地震可能造成的损害的评估。这项研究将提高预测新桥梁和现有桥梁地震反应的知识水平，并将改进加拿大公路桥梁设计规范的抗震设计规定。研究基础旋转对建筑物地震反应的影响，以了解所发生的复杂土-结构相互作用。这项研究计划的目的是为了解释剪力墙的灵活性增加的影响，这是由于剪力墙底部地基的旋转造成的。在非线性有限元分析和全尺寸梁-柱-板组件的反循环加载试验的帮助下，将开发低延性框架成员节点所需的钢筋细节和剪力钢筋，以评估CSA标准A23.3关于混凝土结构设计的适当要求。这些类型的框架是常见的在加拿大东部和中部，但有很少的信息，这些框架成员的细节的影响。这两个研究项目将促进对基础旋转影响和中低延性框架地震反应的理解。本研究将对CSA混凝土结构设计标准进行改进。在使用超高强度混凝土时实现延性柱的设计和详细要求将用于高层建筑。约束加固必须是有效的，以提供一个韧性响应后，突然覆盖剥落发生。使用钢纤维自固结混凝土作为部分替代延性柱约束钢筋的手段也将进行研究。这将产生一种可行的混凝土混合物，具有纤维的额外好处，并有可能减少延性柱的堵塞。这项研究将推进这些新型混凝土性能的知识状态，并将为柱的约束提供实用的解决方案。将研究在厚板混凝土桥梁中使用钻孔锚来提供抗剪加固以避免剪切破坏，并研究碱-硅反应性对抗剪强度的影响。研究了钢筋腐蚀和分层影响下停车库结构的逐渐倒塌。这两项研究的目的是防止现有老化桥梁和停车库结构的失效。

The research program involves two main areas with two projects on earthquake engineering and two projects on the performance of concrete infrastructure.Research will be carried out on the seismic performance of bridges to assess the newly developed seismic design provisions of the 2014 Canadian Highway Bridge Design Code. Methods for predicting damage levels in bridge columns due to different levels of earthquakes will be developed to assist bridge designers in carrying out the new performance-based design procedures. The goal is to provide a design approach that is not only concerned about preventing collapse but also minimizing damage for smaller, more frequent seismic events. Reversed cyclic loading experiments will be carried out to study ways of predicting damage indicators for deficient existing bridge structures and analytical tools for predicting the extent of possible damage will be developed. This Discovery Grant is aimed at improving the safety of older bridges that were designed before proper seismic design procedures were available and will also provide an assessment of likely damage for different levels of earthquakes. This research will advance the state of knowledge in predicting the seismic response of new as well as existing bridges and will lead to improvements of the seismic design provisions of the Canadian Highway Bridge Design Code. Studies on the effects of foundation rotation on the seismic response of buildings will be carried out to gain an understanding of the complex soil-structure interaction that takes place. The aim of this research program is to account for the effects of the increased flexibility of shear walls due to the rotations of the foundations at the base of the walls. With the aid of non-linear finite element analysis and reversed cyclic loading tests of full-scale beam-column-slab sub-assemblies, the reinforcement details and shear reinforcement required in joints of lower ductility frame members will be developed to assess suitable requirements for the CSA Standard A23.3 on the Design of Concrete Structures. These types of frames are common in eastern and central Canada and yet there is little information on the effects of the detailing of these frame members. These two research projects will advance the understanding of the effects of foundation rotation and the seismic response of frames of moderate and low ductility. This research will result in improvements to the CSA Standard for the Design of Concrete Structures.Design and detailing requirements for achieving ductile columns when using ultra-high-strength concrete will be developed for use in high-rise construction. The confinement reinforcement must be effective to provide a ductile response after sudden cover spalling occurs. The use of self-consolidating concrete with steel fibres will also be investigated as a means of partial replacement of confinement reinforcement in ductile columns. This would result in a workable concrete mix with the added benefit of the fibres and has the possibility of reducing the congestion in ductile columns. This research will advance the state of knowledge on the performance of these new types of concrete and will provide practical solutions for the confinement of columns.The use of drilled-in anchors used to provide shear reinforcement in thick slab concrete bridges to avoid shear failures will be investigated and the effects of deterioration due to alkali-silica reactivity on the shear strength will be investigated. Ways of preventing progressive collapse in parking garage structures affected by corrosion of the reinforcement and delamination will be studied. These two studies are aimed at preventing failures in existing deteriorated bridge and parking garage structures.