考虑多次地震和环境影响的钢筋混凝土框架结构全寿命地震易损性与风险评估

面向我国抗震韧性城乡建设计划、实施建成环境可持续发展战略的重大需求，以量大面广且受环境影响较大的钢筋混凝土框架结构为研究载体，考虑结构全寿命周期内发生多次地震的可能性，提出能够考虑多次地震发生的随机性、时变性、丛集性和非平稳性的时变概率危险性分析方法，发展序列地震动记录的选取方法，通过数值模拟和振动台试验研究多次地震作用下锈蚀钢筋混凝土框架结构的抗震性能，对影响锈蚀钢筋混凝土结构的各种不确定性因素和传递关系进行建模和量化，提出多次地震作用下锈蚀结构的时变-状态相关地震易损性分析方法，建立基于Markov链的锈蚀结构全寿命地震风险概率分析模型，发展锈蚀结构全寿命地震灾害损失评估的精细化方法，对多灾害工程模拟平台SimCenter进行二次开发，集成本项目提出的理论和方法，并应用于工程实践，旨在为震前抗震设计、抗震加固和防震减灾规划及震后应急救援、安全评估和修复重建等工作提供理论支持和决策依据。

Orienting to the big demands of construction plan of resilient cities and countryside as well as the major strategy of sustainability of built environments of China, this project will make the research on the life-cycle seismic vulnerability and risk assessment for reinforced concrete frame structures considering both multiple earthquakes and environmental effects, since reinforced concrete structures are the most used structures in built environments and their proneness to environmental attacks, and also due to the possibilities of multiple earthquakes that will occur during the whole life-cycle of an engineering structure. Considering the randomness, time-dependence, clustering, and non-homogeneousness of the occurrence of multiple earthquakes, a time-variant probabilistic seismic hazard analysis (PSHA) approach will be proposed, and then, a method for selecting the ground motion records of earthquake sequences will be developed. The seismic performance of reinforced concrete structures with corroded reinforcements will be investigated by the way of numerical simulation and shaking-table experiments. The different kinds of uncertainty factors influencing the corroded concrete structures will be identified, and the complex relationships among the uncertain parameters will be characterized and quantified. A new method for time-dependent and state-dependent seismic fragility analysis of corroded concrete structures under multiple earthquakes is put forward. Based on the above research, a systematic methodology for life-cycle seismic risk probability analysis and refined seismic loss assessment of corroded concrete structures under multiple earthquakes is developed. A secondary development of the software SimCenter, a platform of multi-hazard simulation, will be conducted by integrating the theory and methodologies of this project. The new platform will be applied to some engineering practices. The project will lay down the theoretical support and decision-making bases for the seismic design, seismic upgrading, and disaster-prevention planning before the happens of earthquakes, as well as for the emergency relief, safety assessment, recovery and reconstruction after the happens of earthquakes.