Seismic risk assessment and mitigation of critical structures

关键结构的地震风险评估和缓解

• 批准号: RGPIN-2014-05171
• 负责人: Lau, David
• 金额: $ 1.75万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=749075
• 关键词: Seismic; risk; assessment; mitigation; critical

In recent years, the trend in earthquake resistant design of structures has been moving towards a performance-based design concept in which the design structure is required to have the reserved strength and displacement capacities to meet a specific desired level of performance, such as life safety, immediate occupancy and uninterrupted continuous operation. In comparison, the level of protection of structures designed following the prescriptive code-based procedures is only qualitatively assumed. As an attempt to realize performance-based seismic design of structures, relationships between prescriptive code provisions in the context of structural response indexes, such as inter-storey drifts, inelastic member forces and deformations, and the performance-based design criteria are assumed following some calibration process. This approach of adapting the existing prescriptive code-based design procedures towards performance based design has the shortcoming that its validity is uncertain. The current calibration procedures generally evaluate performance on the basis of the demands and capacities of individual components, and not necessarily at global structural behaviour. Another problem is that calibration of the engineering demands is determined primarily using analysis models not representative of the true ultimate behaviour of the structures. Accurate calibrations between calculated demands and true structural performance at both component and system level are lacking. A research program is proposed herein to develop advanced seismic risk assessment methodology and tools for more accurate evaluation of the seismic performance of critical bridges, and innovative techniques for mitigation the seismic risk of concrete shear walls. The long-term goal of the research program is to enhance the safety and security of Canada's critical infrastructures, to contribute toward the development and advances of performance-based earthquake engineering and design of safer and more loss-resistant infrastructures. The research program is divided into two broad components of analytical and experimental approaches: (i) Seismic modeling and analysis, and risk assessment of bridge inventories; (ii) Seismic repair and strengthening of reinforced concrete shear wall structures. The research will facilitate a comprehensive understanding of the progressive collapse behaviour of bridges for the first time. It will help to tackle the very costly renewal problem of Canada's deteriorated bridges by giving engineers tools to distinguish dangerous structures from those that will fail but not collapse. For example, a partially damaged bridge may still have the capacity to function as an emergency route bridge for evacuation purposes without the need for costly retrofit. The assessment tools will be very useful for prioritizing and allocation of limited resources for reducing the seismic risk of existing bridge inventory.

近年来，结构抗震设计的趋势一直在朝着基于性能的设计概念迈进，其中设计结构必须具有保留的强度和位移能力，以达到特定所需的性能水平，例如生命安全，即时占用和不间断的持续操作。相比之下，仅定性地假设按照基于规范的代码程序设计的结构的保护水平。 为了实现基于绩效的结构地震设计，在结构响应索引的背景下，规定性代码规定之间的关系，例如层间漂移，无弹性成员力和变形，以及基于性能的设计标准，在某些校准过程之后假定。 这种将现有的基于规范的设计程序适应基于绩效设计的方法的方法是其有效性不确定。 当前的校准程序通常根据单个组件的需求和能力来评估性能，而不一定是在全球结构行为上。 另一个问题是，工程需求的校准主要是使用分析模型确定的，而不代表结构的真实最终行为。 缺乏计算出的需求与组件和系统级别的真实结构性能之间的准确校准。本文提出了一项研究计划，以开发先进的地震风险评估方法和工具，以更准确地评估关键桥的地震性能，以及用于缓解混凝土剪切壁的地震风险的创新技术。 该研究计划的长期目标是增强加拿大关键基础设施的安全性，以促进基于绩效的地震工程以及对更安全和更多耐损失基础设施的设计的发展和进步。研究计划分为分析和实验方法的两个广泛组成部分：（i）地震建模和分析以及桥梁库存的风险评估； （ii）地震修复和增强钢筋混凝土剪切壁结构。这项研究将促进对桥梁的进行性崩溃行为的全面理解。 这将有助于解决加拿大恶化桥梁恶化的续约问题，通过为工程师的工具区分危险结构与将失败但不会崩溃的桥梁区分开来。例如，部分损坏的桥梁仍然可以作为疏散目的的紧急路由桥梁功能，而无需进行昂贵的改造。评估工具对于减少现有桥梁库存的地震风险的有限资源的优先级和分配非常有用。