基于统一倒塌风险的建筑抗震设计方法研究  

Research on seismic design method of buildings based on uniform collapse risk

作　　者：罗开海[1] 保海娥[1] 左琼[1] LUO Kaihai;BAO Haie;ZUO Qiong(China Academy of Building Research,Beijing 100013,China)

机构地区：[1]中国建筑科学研究院,北京100013

出　　处：《建筑结构学报》2022年第2期13-20,共8页Journal of Building Structures

基　　金：住房和城乡建设部专题项目(FZYJ(2015)KZ-7);中国建筑科学研究院标准规范项目(20150122336230031);山东省高校土木结构防灾减灾协同创新中心项目(XTZ201906)。

摘　　要：为了研制基于一致倒塌风险的建筑抗震设计方法,首先对建筑结构地震倒塌风险表征参数及其控制水准进行了研究,认为在工程设计与控制中,可采用规范GB 50011—2010的弹塑性层间位移角限值作为倒塌的判别标准,采用弹塑性层间位移角限值的超越概率表征建筑的地震倒塌风险,风险控制水准建议取10%;其次对基于统一地震危险的抗震设计方法进行了研究,建议将各烈度区50年超越概率2%地震动参数作为建筑倒塌的设防上界,即建筑设防的第三水准参数,依次乘以1/1.5和1/4.5后,分别作为第二水准和第一水准的设计参数;再次,对影响建筑倒塌风险的主要控制措施的调整方案进行了研究,并给出了RC框架结构的弹塑性层间位移角限值取为1/100、进一步提高框架柱最小截面尺寸、降低轴压比限值等修改建议,补充重力荷载代表值下的轴压比不超过0.75和抗震承载力冗余系数的规定;最后,针对典型的6层RC框架结构,进行了基于一致倒塌风险抗震设计方法的试设计和倒塌风险分析。结果表明,按建议方法进行设计,可有效控制建筑结构在50年超越概率2%地震作用下的倒塌风险,所建议的基于一致倒塌风险抗震设计方法合适、可行。In order to develop a seismic design method based on the uniform collapse risk,the characteristic parameters and control level of the earthquake collapse risk of building were examined,and it is pointed out that,during engineering design and control,the inelastic inter-story drift limit by the code GB 50011—2010 can be used as the collapse criteria,and the seismic collapse risk of the building can be characterized by the probability of the exceedance of the inter-story drift limit,and the risk control level is recommended to take as 10%.Secondly,the seismic design method based on uniform seismic hazard is studied,and it is suggested that the seismic parameters with exceeding probability of 2%/50yr of each intensity area should be regarded as the upper bound of the fortification of building collapse,that is,the third level parameters of building fortification,multiplied by 1/1.5 and 1/4.5,respectively,can be as the design parameters of the second level and the first level.Thirdly,the adjustment scheme of the main control measures affecting the risk of building collapse is studied,and some suggestions are put forward to modify the provisions,such as taking the inter-story drift limit of RC frame structure to 1/100,further improving the minimum cross-sectional size of the frame column,reducing the limit for axial compression ratio of column,stipulating a maximum axial compression ratio of 0.75 under the representative value of gravity load,and stipulating a redundancy coefficient for seismic carrying capacity.Finally,according to the typical 6-layer RC frame structure,a series of trial designs and collapse risk analysis based on the uniform-risk seismic design method are carried out.The results show that if the structure is designed in strict accordance with the uniform-collapse-risk-based seismic design method proposed in this paper,the risk of collapse under the 2%/50yr probability earthquake can be effectively controlled,so the proposed seismic design method is appropriate and feasible.

关 键 词：抗震设计方法 统一倒塌风险 一致超越概率 倒塌概率 

分 类 号：TU972.4[建筑科学—建筑设计及理论]