罕遇地震作用下故宫太和殿抗震性能研究

Seismic performance of Tai-he Palace in the Forbidden City under rear earthquake

为有效评估故宫太和殿结构的抗震性能,对其开展罕遇地震作用下的有限元分析。基于榫卯节点、斗拱、柱础平摆浮搁等构造特征,考虑柱-填充墙之间的接触关系,建立太和殿结构的非线性有限元分析模型。通过响应谱分析,研究8度罕遇地震作用下,太和殿结构内力及变形的总体分布特征;通过时程分析,得到太和殿结构典型节点的内力及变形响应曲线,进一步评价了太和殿的抗震性能。结果表明:8度罕遇地震作用下,太和殿墙体易产生受力破坏,明间屋顶部位变形较大,但木构架整体完好,可满足"墙倒屋不塌"的要求;此外,柱础平摆浮搁、榫卯节点、斗拱等构造有利于减小太和殿结构的地震作用响应。

To effectively protect Tai-he Palace in the Forbidden City,its seismic performance under rare earthquake was studied by finite element analysis method. Based on constitution characteristics such as tenon-mortise joints,toukung( bracket sets),free-standing column roots and so on,as well as considering contact relationship between column sides and filler walls,nonlinear finite element model of Tai-he Palace was built. By response spectrum analysis, distributions of internal forces and distortions of Tai-he Palace under 8 degree intensity of rare earthquake were studied. By time history analysis,displacement and acceleration response curves of typical nodes were obtained,by which its seismic performance was further discussed. Results show that under 8 degree intensity of rare earthquake, filler walls of Tai-he Palace are easy to be damaged; middle part of its roof may produce large deformation; however, the wood structure remains intact,which satisfies the requirement that ‘the wall collapse but the house stand '. Besides,constitutions such as tenon-mortise joints,tou-kung( bracket sets),free-standing column roots and so on are helpful for seismic response mitigation.