基于不同评价标准的屈曲约束支撑-钢框架建筑抗震韧性评价研究

Study on seismic resilience assessment of BRB-steel frame building based on various assessment standards

为量化建筑抗震韧性水平,系统化对建筑结构进行韧性评级,国内外逐步颁布了FEMA P-58、REDi、USRC、GB/T 38591—2020《建筑抗震韧性评价标准》四本韧性评级标准。为定量分析国内外相关标准在减震建筑韧性评价上的差异与共通之处,以一幢9层屈曲约束支撑-钢框架减震建筑为例,分别按照国内外标准开展韧性评价,计算其韧性评级、建筑修复费用指标、建筑修复时间指标以及人员伤亡指标。研究发现:GB/T 38591—2020中评级为一星的建筑,其韧性水准大致相当于REDi中的银级建筑及USRC中的三星建筑;设防地震作用下,按国际标准计算得到的修复费用指标比GB/T 38591—2020低60%;不同标准的建筑修复时间指标计算方法存在显著不同,按REDi计算得到的修复时间最长,设防地震作用下达到160 d,按GB/T 38591—2020计算得到的修复时间最短,为16 d;对倒塌概率较低的建筑,按GB/T 38591—2020计算得到的人员伤亡评价指标大于国际标准。此外,国内外标准韧性评价结果皆显示非结构构件损伤对建筑抗震韧性影响较大,应进一步加强对非结构构件基于性能的抗震设计研究。

In order to quantitatively study the seismic resilience level of buildings and systematically evaluate their resilience,four seismic resilience rating standards,namely FEMA P-58,REDi,USRC and GB/T 38591—2020‘Standard for seismic resilience of buildings’,have been developed.To quantitatively analyze the differences and similarities of these resilience assessment standards for buildings with vibration-control buildings,a buckling-restrained braced steel frame was taken as example,and its resilience assessments were carried out according to the four standards.The resilience rating results,cost indexes,repair time indexes,casualty indexes in the four standards were calculated.The results show that the one-star building assessed by GB/T 38591—2020 has approximately the same resilience level as the silver building assessed by REDi and the three-star building assessed by USRC rating system.Under the design-based earthquake,the cost index calculated by international standards is 60%smaller than that obtained by GB/T 38591—2020.The calculation methods of building repair time index show significant difference among the four standards.Under the design-based earthquake,REDi generates the longest repair time index,which reaches 160 days,and GB/T 38591—2020 generates the shortest repair time index,which is 16 days.For buildings with low probability of collapse,GB/T 38591—2020 generates relatively larger casualty indexes.Further,the resilience assessment results of the four standards all indicate that the damage of non-structural components affects building resilience significantly,so it is suggested to enhance the research related to performance-based seismic design of nonstructural components.