Seismic performance assessment and design tools for structural concrete elements having hybrid reinforcement

具有混合钢筋的结构混凝土构件的抗震性能评估和设计工具

• 批准号: 514368-2017
• 负责人: Alam, Shahria
• 金额: $ 2.33万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=643673
• 关键词: Seismic; performance; assessment; design; tools

Insurance Bureau of Canada estimated the overall loss after a 9.0-magnitude earthquake in British Columbia at almost $75B, which reflects the vulnerability of Canadian civil infrastructure. Harsh winter is another critical factor for deterioration of Canadian infrastructure where de-icing salt causes accelerated corrosion to steel. Fibre-reinforced polymer (FRP) bars were introduced as reinforcement in concrete structures to prevent corrosion. However, FRP is a brittle material without inelastic branch. Thus, FRP reinforced concrete (RC) structures exhibit poor ductility with low energy dissipation capacity leading to a major problem in seismic design. This issue can be addressed by introducing hybrid reinforcement where FRP bars can be used along with a ductile material, e.g. steel, or shape memory alloy (SMA) rebar to introduce ductility. FRP rebar cage can be placed in the exterior cage to provide corrosion resistance whereas steel can be used in the inner cage to provide ductility. Since SMA is also good against corrosion but costly, it can be placed at the plastic hinge region, and spliced with other rebar type in the outer cage of RC elements. Little research has been directed towards hybrid reinforcement where FRP rebar is used along with another ductile material and using spliced connections. This study will determine the seismic behavior of concrete bridge piers having hybrid reinforcement, and compare its performance to that of a regular steel RC bridge piers in terms of *load-displacement, moment-rotation and energy dissipation capacity, and strains in the longitudinal and transverse reinforcements. Currently, there is no numerical tool available to predict the response of RC elements having hybrid reinforcements. Hence, another important objective of this study is to develop numerical tools to predict the response of RC elements having hybrid reinforcements in terms of *moment-curvature response, pushover response, and seismic response and implement them in S-Frame Software. These tools will assist in developing performance-based design guidelines and performing fragility assessment for such hybrid RC elements and structures.

加拿大保险局估计，不列颠哥伦比亚省发生9.0级地震后，总损失近750亿美元，这反映了加拿大民用基础设施的脆弱性。严冬是加拿大基础设施恶化的另一个关键因素，因为除冰盐会加速对钢铁的腐蚀。纤维增强聚合物(FRP)筋被引入混凝土结构中以防止腐蚀。然而，FRP是一种没有弹塑性分支的脆性材料。因此，FRP钢筋混凝土(RC)结构延性差，耗能能力低，是抗震设计中的一个主要问题。这个问题可以通过引入混合加固来解决，其中FRP筋可以与延性材料(如钢)或形状记忆合金(SMA)钢筋一起使用来引入延性。FRP钢筋笼可放置在外笼中以提供耐腐蚀性，而钢材可用于内笼以提供延性。由于SMA也具有良好的抗腐蚀性能，但价格昂贵，因此可以将其放置在塑性铰区域，并与其他类型的钢筋拼接在RC构件的外笼中。很少有研究针对混合加固，其中FRP钢筋与另一种延性材料一起使用，并使用拼接连接。本研究将确定混杂配筋混凝土桥墩的抗震性能，并将其与普通钢筋混凝土桥墩在荷载位移、弯矩转角和耗能能力以及纵向和横向钢筋应变方面的性能进行比较。目前，还没有可用的数值工具来预测混杂配筋钢筋混凝土构件的反应。因此，本研究的另一个重要目标是开发数值工具来预测具有混合配筋的钢筋混凝土构件的弯矩-曲率反应、Pushover反应和地震反应，并在S框架软件中实现。这些工具将有助于制定基于性能的设计指南，并对这种混合RC构件和结构进行易损性评估。