故宫太和殿抗震性能研究

为合理保护太和殿,采取有限元分析方法研究其抗震性能.基于太和殿的典型构造特征,采用三维弹簧单元模拟榫卯节点及斗拱构造,建立太和殿有限元模型.通过模态分析,获得太和殿的基频及主振型;通过施加水平双向单点谱,分析太和殿在8度地震作用下的内力和变形,评价太和殿的抗震性能.结果表明:太和殿主振型以平动为主,且在水平向的振动关联很小;8度常遇地震作用下,太和殿的变形和内力很小,可满足抗震要求;8度罕遇地震作用下,太和殿的变形在容许范围内.此外,太和殿墙体对限制太和殿木构架侧移、减小部分木构架内力具有一定贡献.

Aseismic behaviors of Tai-he Palace in the Forbidden City

To effectively protect Tai-he Palace in the Forbidden City, its aseismic performances were studied by finite element analysis methods. Based on typical constitutions of Tai-he Palace, 3-dimension spring elements were used to simulate its tenon-mortise joints and tou-kungs (bracket sets) to build its finite element model. By modal analysis, its basic frequencies as well as main modes were obtained; by applying 8-degree intensity of single-point response spectrums in level directions to the model, its aseismic behaviours were studied. Results show that main modes of Tai-he Palace are of translation, which have little relation between each other in level directions; under 8-degree intensity of frequently occurred earthquakes, its internal forces as well as structural deformation meet the demand of earthquake fortification; under 8-degree intensity of seldom occurred earthquakes, its maximum deformation value is within the permission scope. Besides, its filler walls are helpful for reducing deformation as well as internal forces of part of the wooden structure.