既有多层砌体住宅增设电梯与抗震加固综合改造技术振动台试验研究

Shaking table tests on existing multi-story masonry residence with integrated technology of elevator retrofitting and seismic strengthening

我国现有大量建于20世纪七、八十年代的老旧砌体结构住宅,这类住宅材料强度较低,抗震性能较差,大都有抗震加固、增设电梯等结构安全性与建筑功能提升的需求。为避免两项需求单独实施引起的资源浪费,减少入室施工等对房屋正常使用与周边环境的影响,提出了既有多层砌体住宅增设电梯与抗震加固综合改造技术,并制作了一组多层砌体结构缩尺(1∶4)模型,即模型A(未加固的五层无筋砌体结构模型)和模型B(增设电梯、抗震加固综合改造模型),进行了振动台模型对比试验验证。试验结果表明:砌体住宅采用综合改造技术加固后,刚度、基底剪力均有较大幅度提高,结构整体抗震能力明显提高,其脆性破坏的特征亦有显著改善;此外,由于增设的电梯井剪力墙显著增强了结构横向的抗震能力,使得房屋纵、横两个方向的抗震性能趋于均衡,有效地改善了多层砌体结构住宅存在明显抗震强、弱向的自身缺陷。

A considerable number of multi-story masonry residence buildings were built in the 1970 s and 1980 s,and a great portion of them had a low material strength and poor seismic performance.Presently,these old multi-story residence buildings usually have demands for retrofitting elevators and seismic strengthening.In order to avoid the waste of resources and energy caused by satisfying the two demands separately,and to reduce the influence on the residence and the surrounding environment due to indoor-working,an integrated design technology for elevator retrofitting and seismic strengthening for multi-story masonry residence building was proposed.Shaking table tests of 1∶4 scaled models including Model A(unstrengthened five-story unreinforced masonry structure model)and Model B(model with integrated elevators installing and seismic strengthening)were conducted to verify the proposed technology.The experimental results show that,after being strengthened by the proposed integrated technology,the stiffness and ductility of the masonry structures are enhanced significantly,and the overall seismic capacity is improved evidently.The brittle failure characteristics of the masonry structures are also improved obviously.Furthermore,the additional shear wall of elevator shaft significantly enhances the transversal seismic capacity of the model,which makes the seismic performance of the building in the longitudinal and transverse directions tend to be balanced,and effectively improves the defects of the multi-story masonry structure housing in the strong and weak seismic directions.