10—14世纪四柱亭榭之结构探析

Research on the Structure of Four-pillar Pavilion from the 10th to the 14th Century

通过对金元亭榭、《营造法式》以及相关宋画三者进行对照比较,总结出10—14世纪四柱亭榭之结构做法,内容包括举折、出檐、出际、安槫四项。具体提出以下5点结论:1)举屋在四分举一至二分举一之间;2)椽径份值介于9～10份;3)大型亭榭之出檐,可参考《法式》规定,小型亭榭之出檐,需据檐步架尺寸进行折算;4)歇山亭榭之出际可据步架尺寸之0.8～1确定;5)安槫方式可归作三类:"斗栱悬挑型"、"过渡型"和"趴梁抬承型",每一类又可进一步细分为两种做法,在此基础上,对不同做法之历史演变进行了客观梳理。研究结果可为中古亭榭建筑结构补阙,又可补充完善《法式》内容。

Through comparing the pavilions of Jin and Yuan dynasties,Yingzao fashi and related Sung paintings,the paper summarized the structure practice of four-pillar pavilion in the period from the 10th to the 14th century,which includes how to position purlin,how to determine the length of flying eaves and rafter,how to calculate the length of overhanging purlin,and how to rise the intermediate purlin below.5 specific conclusions were put forward:1)the height of the ridge purlin is between a fourth to a half of the distance of rear and front eaves purlin;2)the modulus of rafter is between 9 to 10;3)the rules of the length of rafter relate only to large pavilion,using provisions of Yingzao fashi,while to small one,the length is determined by the size of the eaves step frame;4)the length of overhanging purlin is between four fifths to one of the size of the step frame for pavilion with gable and hip roof;5)The methods of raising the intermediate purlin below can be classified into three categories:“cantilevered by dougong”,“transition state”,“rised by beam”,each of which can be further subdivided into two approaches.Step further,combed the historical evolution of the methods above.The results can be used to supplement the architectural structure of the middle ancient pavilion,also to supplement Yingzao fashi.