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: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=696228
• 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 级地震后的总体损失接近 $75B，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，除冰盐会加速钢铁腐蚀。纤维增强聚合物（FRP）钢筋被引入混凝土结构中以防止腐蚀。然而，FRP是一种脆性材料，没有非弹性分支。因此，FRP钢筋混凝土（RC）结构的延展性差，耗能能力低，导致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 杆可以与延性材料（例如，玻璃纤维增​​强塑料）一起使用。钢或形状记忆合金 (SMA) 钢筋以引入延展性。外部笼可放置玻璃钢钢筋笼以提供耐腐蚀性，而内部笼可使用钢材以提供延展性。由于SMA也具有良好的抗腐蚀能力，但成本较高，因此可以将其放置在塑料铰链区域，并与RC元件外笼中的其他钢筋类型拼接。针对混合加固的研究很少，其中 FRP 钢筋与另一种延性材料一起使用并使用拼接连接。本研究将确定具有混合钢筋的混凝土桥墩的抗震性能，并将其性能与常规钢 RC 桥墩的性能进行比较： 荷载位移、力矩旋转和能量耗散能力，以及纵向和横向钢筋的应变。目前，没有可用的数值工具来预测具有混合增强材料的 RC 元件的响应。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增强材料的 RC 元件在以下方面的响应： 弯矩曲率响应、推覆响应和地震响应，并在 S-Frame 软件中实现它们。这些工具将有助于制定基于性能的设计指南，并对此类混合 RC 元件和结构进行脆弱性评估。