单跨RC框架结构的抗震倒塌能力分析

Analysis of Seismic Collapse Capacity of Single Span RC Frame Structures

学校建筑中的连廊经常使用单跨框架结构,而关于单跨框架结构的抗震倒塌能力定量评价较少。按《建筑抗震设计规范》(GB 50011—2010)设计了17个连廊框架模型,分别进行基于动力增量分析方法的倒塌易损性分析,用倒塌概率和安全储备系数定量评价各模型的抗震倒塌能力。结果显示,相比同层数的双跨框架结构,本例单跨框架结构的抗震倒塌能力冗余度高;1层乙类单跨框架结构,通过提高一度采取抗震措施或提高一度计算地震作用均能提高结构的抗震倒塌能力,使结构倒塌概率在可接受的范围,且提高一度计算地震作用比提高一度采取抗震措施更能提高结构的抗震倒塌能力;提高框架梁的抗震性能对提高结构抗震倒塌能力作用很小,而提高框架柱的抗震性能能较大地提高结构抗震倒塌能力;用安全储备系数归一条件下的造价来评价,提高框架柱抗震性能比提高一度采取抗震措施更经济。

The corridors in school buildings often use single span frame structures,but there is less quantita-tive evaluation criterion of the seismic collapse resistance of single span frame structures.17 corridor frame mod-els were designed according to the Code for Seismic Design of Buildings(GB 50011—2010),and the collapse vulnerability analysis based on dynamic incremental analysis method was conducted.The collapse probability and safety reserve coefficient were used to quantitatively evaluate the seismic collapse resistance of each model.The results showed that in this case,the single span frame structure had a higher redundancy in collapse resist-ance compared to the double span frame structure.The Class B single storey single span frame structure could improve the seismic collapse resistance by improving seismic measures or earthquake actions by one seismic in-tensity,making the probability of structural collapse within an acceptable range.Moreover,improving seismic actions could better enhance the seismic collapse resistance than improving seismic measures.Improving the seismic performance of frame beams produced little effect on the seismic collapse resistance,while improving the seismic performance of frame columns could greatly improve the seismic collapse resistance.Evaluating the cost of normalized safety reserve coefficient,improving the seismic performance of frame columns were more econom-ical than improving structural seismic measures by raising one seismic intensity.