关于建筑结构抗震设计若干问题的讨论

对当前建筑结构抗震设计中若干原则性问题进行讨论，提出：建筑结构抗震设计不适宜采用概率可靠度方法而更适合采用多安全系数设计方法；应以设防烈度地震即中震的地震动参数进行结构承载力设计，依R-μ-T规律改进设计中的地震作用-延性等级组合；当结构的计算基底剪力不满足规定的最小基底剪力时，可以加大地震作用力，而不应该调整结构的刚度来加大地震反应；比较了巨型框架与普通框架结构的侧向刚度，说明巨型框架的侧向刚度远较普通框架差，不具备承担一定比例地震作用剪力的必要刚度，而应令核心筒承担全部的地震剪力；我国现行规范对结构的层间位移角限值过于严格，分析其主要原因并建议大幅度放宽。

Discuss on issues of seismic design of building structures

In this paper, some principle issues about the seismic design of building structures are discussed. The multi-safety factor method can be more suitable than the probabilistic reliability method for the seismic design of building structures. It is suggested that the ground motion parameters corresponding to the fortification intensity level be used to check the load carrying capacities of structures. The earthquake load ductility level combination can be improved for the design according to the R-μ-T rules. When the calculated base shear does not meet the minimum base shear requirement, the seismic force can be increased instead of adjusting the stiffness of the structure to increase the seismic responses. The lateral stiffness of the mega-frame structure is much smaller than that of the normal frame structure. The mega-frame can not bear a certain proportion of the total seismic shear force as it hasn’t the necessary lateral stiffness. Instead, the core tube should be designed to bear all the earthquake shear force. The story drift limits are too strict and should be substantially relaxed.