北大红楼砖木结构建筑的数值仿真分析

Seismic Numeric Emulation on Brick and Timber Structure of Beida Red Building

采用地震反应谱和时程分析的方法对北大红楼这一具有历史意义的砖木建筑的性能进行了数值仿真分析,从中找出薄弱环节,可指导加固改造工作。数值仿真分析得出的主要结论:1)结构的位移反应较小,说明结构整体刚度较大,结构中部的刚度相对较弱,这和横墙间距过大有直接的关系,整体结构的最薄弱部位集中在结构中部两侧对称区域的横墙上;2)8度多遇地震作用下,最大剪应力出现在结构层1的底部;3)木龙骨楼板具有内力传递的方向性和不均匀性,整体性相对较弱;4)结构加固的重点应该在结构中部两侧对称区域的横墙和楼板的整体性加强上。

The earthquake response spectrum analysis and time history analysis are applied to the numeric emulation of Beida Red Building which is a history building to find the weak link and indicate the orientation of reinforcement work. The main conclusion of numeric analysis is descripted. The structure reflection of displacement is small, which explains that the structure stiffness is large. The stiffness of middle part in structure is relatively feeble, which is in direct relation to excessive space between cross walls. And the cross walls of middle part are the weakest link in the whole structure. The biggest shear stress lies in the base of first floor under the multi frequency seismic of 8 degree. The directivity and inhomogeneity are the characteristics of wood keel plate in transfer of endogen force. The intensification of the cross wall and floor in equiliateral region should be the orientation of structure reinforcement.