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: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=588249
• 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已转向基于性能的设计理念，即要求设计结构具有预留的强度和位移能力，以满足特定的预期性能水平，例如生命安全相比之下，按照规范性规范程序设计的结构的保护水平只是定性假设的，作为实现基于性能的结构抗震设计的尝试，规范性规范条款之间的关系。结构的上下文响应指标，例如层间位移、非弹性构件力和变形，以及基于性能的设计标准是在一些校准过程之后假设的。这种将现有的基于规范的设计程序调整为基于性能的设计的方法具有以下缺点：其有效性是不确定的。当前的校准程序通常根据各个部件的需求和能力来评估性能，而不一定是全局结构行为。另一个问题是工程需求的校准主要是使用不代表结构的分析模型来确定的。真正的最终行为计算需求与组件和系统级别的真实结构性能之间缺乏准确的校准。 本文提出了一项研究计划，旨在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梁的抗震性能，以及减轻混凝土剪力墙地震风险的创新技术。该研究计划的长期目标是。提高加拿大关键基础设施的安全性，促进基于性能的地震工程的发展和进步，以及更安全、更抗损失的基础设施的设计。该研究计划分为分析和实验方法的两大组成部分： （我） (ii) 钢筋混凝土剪力墙结构的抗震修复和加固。 这项研究将首次促进对桥梁渐进式倒塌行为的全面了解，为工程师提供区分危险结构和那些会倒塌但不会倒塌的结构的工具，有助于解决加拿大老化桥梁的昂贵更新问题。例如，部分受损的桥梁可能仍然有能力作为疏散用途的紧急路线桥梁，而无需进行昂贵的改造。评估工具对于优先考虑和分配有限的资源以减少现有的地震风险非常有用。桥梁库存。