超限高层结构构件抗震性能分析若干问题探讨

Discussion on some practical problems about seismic performance analysis of tall building structures beyond code limit

针对超限高层结构设计中构件抗震性能分析存在若干问题进行探讨。对底部加强区主要墙肢和扭转变形较大的竖向构件,常规的加强方法是提高其承载力,但会造成结构的耗能能力降低,反而对抗震不利。根据其作为结构第一道防线的耗能特点,提出了通过提高其延性的方式进行加强。对弱连接楼板损坏情况,常规的构件加强方式是使其满足设防地震作用下不屈服要求,但在罕遇地震作用下该处的构件损坏较严重。说明弱连接楼板仅满足设防地震作用下的不屈服要求不能有效保证结构平面的完整性。建议将弱连接处的楼板和框架梁定义为关键构件,以及在罕遇地震作用下楼板满足抗拉不屈服和抗剪截面验算。

Some practical problems about seismic performance analysis of tall building structures beyond code limit were discussed.Conventional strengthening methods is to improve the bearing capacity of bottom strengthening area of the main wall-pier and corner vertical member with large torsional deformation,but it will reduce the energy dissipation capacity of structure,which is disadvantageous for earthquake resistance.According to its characteristic of energy dissipation as the first defense system of the structure,it is proposed to improve the ductility of members.In the case of damage of components of the weak-linking slab,conventional strengthening methods of components is to meet the non-yielding requirements according to the seismic resistance,but the damage of components is the more serious under rare earthquakes.It is shown that the weak-linking slab can not guarantee the integrity of the structural plane effectively only meet the non-yielding requirements under seismic resistance.It is suggested that the slab and the frame beam of the weak-linking part should be defined as the key components,and meet tensile the non-yielding and the shear section under rare earthquake.