外附减震子框架提升既有RC框架结构抗震性能

Seismic performance of existing RC frame structure retrofitted with external energy dissipation substructure

为了对比外附屈曲约束支撑子框架的不同形式对既有钢筋混凝土框架结构进行消能减震加固的区别。根据《建筑抗震设计规范》(GB 50010-2010)的反应谱,忽略屈曲约束支撑子框架质量,利用未设置屈曲约束支撑的单自由度体系和设置屈曲约束支撑的单自由度体系的层间抗侧刚度比,推导了两者周期、层剪力和层间位移的计算式。将屈曲约束支撑子框架作为既有钢筋混凝土框架结构增设的抗侧力子结构,给出了多遇地震作用下的刚度比-层间位移和层剪力曲线。随后,针对多自由度体系,忽略阻尼的影响,基于变形叠加原理论述了未设置与设置屈曲约束支撑子框架体系之间的周期、层位移和层剪力的关系式。基于推导的相关计算式并结合实际工程应用总结,提出了设置屈曲约束支撑子框架加固既有多层钢筋混凝土框架结构的实用设计流程。最后,结合工程案例对比了采用钢筋混凝土子框架与钢结构子框架的区别,算例表明,采用屈曲约束支撑钢结构子框架体系更具有优势。

In order to compare the different forms of externally buckling restrained braced substructures,the energy dissipation and seismic strengthening of available reinforced concrete frame structures are carried out.According to response spectrum of the code for seismic design of buildings(GB50010-2010),the single-degree-of-freedom(SDOF)system without BRB and the single-freedom frame system with BRB are used,The formulas for calculating the period between them and the shear force and displacement between layers are derived.Using the concept of lateral stiffness ratio,based on the concept of lateral stiffness ratio,the curves of stiffness ratiointer-story displacement decrease and inter-story shear increase under frequent earthquake action is established.Then,for the multidegree-of-freedom(MDOF)system,based on the principle the same deformation curves can be superimposed without considering the effect of damping,the formulas of period,inter-layer displacement and inter-layer shear force between the unset and set BRB system are given.Based on the derived calculation formulas and the summary of practical engineering application,a practical design process of setting buckling restrained brace substructure to strengthen the available multi-storey reinforced concrete frame structure is proposed.Finally,Combined with the engineering case,the difference between the reinforced concrete substructure and the steel substructure is compared.Finally,combined with an engineering case,the difference between reinforced concrete substructure and steel substructure is compared.The example shows the steel substructure system with buckling restrained brace has more advantages.