故宫太和殿木构件现状分析及加固方法研究

为加强对古建筑的维修保护,故宫博物院对太和殿进行了勘查,发现如下木构件问题:西山挑檐檩跨中挠度过大;三次间正身顺梁及山面扶柁木榫头位置下沉10cm;明间藻井下垂13cm,井口爬梁已经开裂.通过运用结构力学相关方法,对这些构件的结构现状进行理论分析,研究了问题产生的原因,讨论了相应的加固方案,解决了这些问题.结果表明:西山挑檐檩虽然挠度较大,但强度满足要求,不需要加固;山面扶柁木榫头下沉的原因是局部受弯强度不足,但已通过支顶解决该问题;正身顺梁榫头下沉的可能原因是材料老化,局部受拉、弯、剪强度不足,通过采用钢木组合结构进行了加固;藻井下沉的原因是木材老化,井口爬梁抗弯及抗压承载力不足,通过采用扁钢箍加固的方法进行了加固.研究结果可为古建筑保护及修缮提供参考.

Study on mechanical problems and strengthening methods on some components of the Taihe Palace in the Palace Museum

Perambulation on the Taihe Palace in the Palace Museum is carried in order to protect and maintain it.During the process,some mechanical problems of its components appear as following:The maximum flexibility of the seeking out beam on the west side of the building reaches 13 cm,which exceeds the limits of the wood design standard of China;The tenon of the face beam of 3 width part of the building goes down 10 cm;The tenon of the side beam of the 3 width part of the building goes down 10 cm but the beam has been supported;The caissons and ceilings in the central part of the building goes down 13 cm and the Jingkou beam on it has splitted.These problems are analysed by techniques of structural mechanics and relative strengthening methods are discussed to solve them.Results of the study show that the reason the flexibility of the seeking out beam is very large is that the wood material grows old and its elastic ratio decreases,but the intensity of the beam still fits the design standard;The reason that the tenon of the side beam goes down is that its strength of bending decreases,but the problem has been solved by additional supporting;The possible reason that the tenon of the face beam goes down is that the wood material grows old and some part of its strength of extension,bending and shearing are insufficient,and steel wood strengthening structure is used to solve the problem;The reason that the caissons and ceilings goes downs is that the wood material grows old and the strength of bending and compression of the Jingkou beam are insufficient,flat steel is utilized to strengthen it.The results of study are favorable for protection and remedy of Chinese ancient buildings.