清代多层小式木作结构整体抗震性能分析

Analysis of Overall Structural Seismic Performance of Qing Dynasty Multi-storey Small Timber Structure

以嘉峪关关楼为对象,采用SAP2000有限元软件建立了关楼整体结构空间有限元数值分析模型,通过动力时程分析,得到了结构各层的动力放大系数,并与大式木作结构的动力放大系数对比,结果表明小式木作结构具有和大式木作结构相同的柱脚隔震和榫卯连接的耗能减震作用,但不同的是小式木作结构在屋顶处具有明显动力放大现象,檐柱上的斗栱隔震减震效果不明显,仅起到装饰作用,且其整体的耗能减震效果不及大式木作结构。最后,基于能量平衡理论的能量耗散分析,得出清代多层小式木作结构在地震作用下,其耗能减震作用主要体现在榫卯的连接上,约占71.2%,柱础的隔震减震作用相比榫卯连接的耗能减震作用较小,仅占3.2%。

The Jiayuguan pass tower was selected as a research object.The overall structure spatial finite element numerical analysis model was established by SAP 2000 finite element analysis software.By the dynamic time history analysis on the small timber structure model,the dynamic amplification factor of each layer was obtained.From the compar-son of the structure dy namic amplification factor with that of large timber structure （ta-mu-tso）,the results show that they had common vibration isolation of the float connection and friction energy dissipation of mortise-tenon joints of beam-column,with the difference in that the small timber structure had obvious dynamic amplification phenomenon in the roof,and the tou-kung on eaves column hardly had aseismic ability but decorative function,and its overall energy damping effect is less than ta-mutso.In the end,from the theory of energy balance analysis of the energy dissipation on Qing Dynasty Multi-storey small timber structure model,the results show that friction energy dissipation were mainly incarnated on the mortise-tenon joints of beam-column,which accounted for about 71.2％.The vibration isolation of the float connection between column foot and plinth was smaller than that of mortise-tenon joints of beam-column,which accounted for only 3.2％.