钢筋混凝土框架结构地震倒塌模式优化与整体抗震能力设计方法

One of the main reasons for structural collapse under strong earthquakes lies in the fact that the unfavourable structural seismic collapse modes and the concentrated interstory deformation leads to the absence of maximum collapse-resistant capacity. Accordingly, in order to solve the key problems on the optimization of structural seismic collapse modes and structural global seismic design for reinforced concrete (RC) frame structures, this proposal aims to develop an optimization design approach of structural seismic collapse modes based on the refined numerical model which can simulate the whole process of nonlinear dynamic evolution. The optimization approach, with the goal of maximizing the structural earthquake-resistant capacity, can track the failure path and component damage evolution, and therefore eliminates the weakest collapse modes and strengths the failure path. The proposed design approach will be verified through the lab test of a typical structural model whose seismic collapse mode has been analyzed and optimized. Then, based on the seismic performance goal of uniform deformation, global energy dissipation mechanism and maximizing the collapse-resistant capacity, a uniform damage-based seismic design procedure is proposed based on the component damage index, to achieve the effective enhancement of collapse-resistant capacity. Finally, based on the state of uniform damage for RC frames under strong earthquakes, new equivalent design lateral force pattern and the distribution of strong-column weak-beam ratio is established, and the nonlinear global seismic capacity design approach is proposed based on the global system concept. This proposal can provide the scientific support for the seismic safety construction and earthquake prevention and disaster reduction of RC frame structures in China, with important theory and practice significances.

建筑结构在强震下倒塌失效的主要原因在于结构形成不合理的倒塌模式、结构损伤出现集中而使结构抗倒塌能力未达到最大化。为此，围绕混凝土框架结构地震倒塌模式优化和整体抗震能力设计中的关键科学问题，本项目通过结构在强震下的非线性动力灾变全过程数值模拟，提出以结构抗倒塌能力最大为目标、能跟踪失效路径和构件损伤演化、从而消除最弱倒塌模式和强化失效路径的倒塌模式优化方法，并通过典型结构的倒塌模式分析、优化及其模型试验，验证项目所提方法的有效性。其次，基于结构变形均匀化、耗能全局化和抗倒塌能力最大化的抗震目标，提出以构件损伤为基础的均匀损伤设计方法，实现结构抗倒塌能力的大幅提升。最后，发展结构实现均匀损伤状态时的新型等效侧向力模式和强柱弱梁系数分布，基于结构整体系统概念，提出结构非线性整体抗震能力设计方法。本项目研究，可为我国混凝土框架结构的抗震安全建设和防震减灾提供科学依据，具有重要的理论和工程实际意义。

建筑结构在强震下倒塌失效的主要原因在于结构形成不合理的倒塌模式、结构损伤出现集中而使结构抗倒塌能力未达到最大化。为此，围绕混凝土框架结构地震倒塌模式优化和整体抗震能力设计中的关键科学问题，本项目通过结构在强震下的非线性动力灾变全过程数值模拟，提出了以结构抗倒塌能力最大为目标、能跟踪失效路径和构件损伤演化、从而消除最弱倒塌模式和强化失效路径的倒塌模式优化方法，并通过典型结构的倒塌模式分析和优化，验证了项目所提方法的有效性。其次，基于结构变形均匀化、耗能全局化和抗倒塌能力最大化的抗震目标，提出了以构件损伤为基础的均匀损伤设计方法，实现了结构抗倒塌能力的大幅提升。基于均匀损伤失效模式，提出了基于规范格式的钢筋混凝土框架结构非线性抗震设计侧向力分布公式。基于新型侧向力模式和“强柱弱梁”整体失效模式，发展了结构非线性整体抗震能力设计方法。本项目研究，可为我国混凝土框架结构的抗震安全建设和防震减灾提供科学依据，具有重要的理论和工程实际意义。