关于钢结构抗震存在的问题及建议

本文探讨了目前钢结构抗震设计中存在的两个主要问题:其一是钢结构的地震作用,由于多高层钢结构房屋被列入“建筑抗震设计规范”(GB50011-2001)中时没有考虑钢结构延性好和弹性阶段阻尼比较小的特点,使得钢结构地震作用偏大,用钢量偏高;其二是钢结构承载力抗震调整系数对梁和焊缝的规定与焊缝强度高于母材强度的实际情况不符,造成设计困难。本文对现行抗震规范、“建筑工程抗震性态设计通则”和美国UBC规范的地震作用进行了分析比较,提出按照耗能能力将钢结构体系分为四类,在此基础上引入结构体系调整系数,对每类结构的地震作用取值给出建议。针对梁柱刚性连接,从抗震设计原则出发,对7、8和9度区分别建议了适合采用的连接形式,并给出了小震和大震下的设计验算公式。

Some problems and suggestions on seismic design of high-rise steel structures

Two major problems existing on the seismic design of high-rise steel structures are discussed: over-estimation of earthquake action for such structures and inconsistency between the adjustment coefficient of seismic capacity for steel members and that for connections.By means of the comparison of the seismic actions defined in the current Chinese Code with those defined in the General Rule for Performance-based Seismic Design of Buildings,and the AISC Seismic Provisions,it is proposed to classify the steel structural systems into four categories by their energy-dissipating capacity,followed by introducing an adjustment coefficient of structural system,the value of which is also suggested for each category.Based on seismic design principles some appropriate connection forms are proposed for the rigid beam-to-column connection used in the regions of seismic intensity 7,8 and 9,and the design formulas for small and severe earthquakes are put forward as well.