某超高层建筑不同抗侧力体系抗震性能对比研究

Study on seismic performance of a super-tall building with different lateral force resisting systems

超高层建筑对水平荷载(风荷载和地震作用)具有较高的敏感性,合理的抗侧力体系对超高层建筑结构的经济性、安全性以及材料使用效率等影响重大。以北京在建的某超高层建筑设计初期所采用的半高和全高支撑两个方案为研究对象,利用MSC.Marc建立了两个方案的有限元分析模型,并进行了工程量、弹塑性时程和倒塌分析。通过工程量统计,对比分析两个方案主体结构材料总用量以及各类构件材料用量差异;通过弹塑性时程分析和倒塌分析,研究两个方案在不同地震水准下的结构响应和抗倒塌能力。结果表明:该工程的两个结构方案都能满足规范规定的抗震性能需求,全高支撑方案具有更好的经济性,比半高支撑方案节省总材料用量约11%,且抗地震倒塌安全储备提高了约14.8%。

The super-tall building is very sensitive to the lateral loads including wind load and seismic action,thus it＇s important to adopt a reasonable lateral force resisting system to ensure the economy,safety and efficiency of the supertall building. Two preliminary designs of a super-tall building in Beijing,with different lateral force resisting systems,were taken as the research objects in this paper,and their finite element models were established subsequently. The total material consumptions of these two designs,as well as the material consumptions of each type of components,were calculated and compared. The seismic responses under different seismic hazards and the collapse resistances were also discussed using nonlinear time history analysis and collapse analysis. The results indicate that both designs can meet the seismic requirements specified in the seismic design code. The ‘fully-braced ＇ design scheme is more economical,whose total material consumption is 11% less than that of the ‘half-braced＇design scheme,while the seismic collapse resistance is 14. 8% larger than the ‘half-braced＇design scheme.