外附子结构及减隔震技术在既有建筑加固中的应用研究

Study on application of external substructure and seismic isolation technology in existing building reinforcement

既有建筑加固改造是可持续发展和节能减排的重要形式,此外国家颁布了更为严格的减隔震设计标准。为推动外附子结构和减隔震技术在加固工程中的应用,以地震高烈度区某医院为例,采用钢框架为外附子结构,运用ETABS建立4个减隔震加固模型,并用MIDASGen对2个减震模型进行优化。研究发现单独使用BRB减震时层间位移角在中震下不满足1/400限值,且剪力增大了9.8%~21%,提出了BRB多阶段屈服设计理念。BRB+VFD组合减震的位移减震率达50%以上,此外VFD与BRB错位安装更利于消能减震。单独采用隔震加固在较高强度地震下的位移减震效果有限,而BRB+LRB混合减隔震加固的层间位移角减震率高达84.2%,剪力减震率高达76.8%。对比验证了混合减隔震加固技术的优良性能,并提出几种典型的外附子结构连接构造方式,为类似加固改造工程提供经验。

Reinforcement and reconstruction of existing buildings is an important form of sustainable development and energy conservation and emission reduction. China has promulgated a more stringent design standard for seismic isolation. In order to promote the application of external substructure and seismic isolation technology in reinforcement engineering, a hospital in the high seismic intensity area is taken as an example. The steel frame is used as the external substructure, and ETABS is used to establish four seismic isolation and reinforcement models. MIDAS Gen is used to optimize the two seismic isolation models. It is found that the inter-story displacement angle of BRB alone does not meet the 1/400 limit value under moderate earthquake, and the shear force increases by 9.8%~21%, so the multi-stage yield design concept of BRB is proposed. The displacement damping rate of BRB + VFD combination is more than 50 %, and the dislocation installation of VFD and BRB is more conducive to energy dissipation. The displacement damping effect of isolation reinforcement alone is limited under high strength earthquakes, while the interlayer displacement angle damping rate of BRB + LRB hybrid isolation reinforcement is up to 84.2 %, and the shear damping rate is up to 76.8 %.The excellent performance of the hybrid seismic isolation reinforcement technology is verified by comparison, and several typical external substructure connection construction methods are proposed to provide experience for similar reinforcement and reconstruction projects.