应县木塔屋架尺度设计再考

Re-examination of Dimensional Design of the Roof Structure of the Sakyamuni Pagoda in Ying County,Shanxi Province

本文回顾了已有“2023清论”关于应县木塔屋架尺度设计的实测和研究结论;针对数据缺漏之处,研究利用三维激光扫描对应县木塔五层藻井以上部分屋架进行了补测。通过数据分析,本文修正了既有研究中关于应县木塔屋架尺度设计的部分假说,推算得到:一、屋架丈尺总体简明,符合整(半)尺设计;二、自檐柱中至脊槫,各段架道平长值依次为6.5尺、6.5尺、7尺、7尺,体现等分思想;举高值依次为3尺、3.5尺、4.5尺、5.5尺;顶部八角井口平长约为8.8尺,井口叠垒高度3.5尺;三、橑檐枋上皮至最上层井口方上皮高度为21尺;橑檐枋至脊槫高17.5尺,为二者间平长的五分之三。根据尺度复原结果,研究提出了屋架几何设计的两种可能思路。

This paper reviews the results of the“2023 Tsinghua Research”on the roof structure design of The Sakyamuni Pagoda in Ying County,and makes a supplementary survey on the roof structure above the ceiling by 3D laser scanning.By data analysis,this paper revises some hypotheses about the dimensional design of the roof structure of the pagoda,and the following conclusions are derived:(1).The dimension of the roof structure conforms to the principle of numeric conciseness.(2).From the midline of the eave column to the ridge(Jituan),the horizontal lengths of each section of the roof structure are 6.5 chi,6.5 chi,7chi,and 7chi,reflecting the idea of equal division;the heights of each section are 3 chi,3.5 chi,4.5 chi,and 5.5 chi.The horizontal length of the octagonal structure at the top is about 8.8 chi,and the stacking height is 3.5 chi.(3).The height from Liaoyanfang to the upper surface of the top octagonal structure is 21chi,and the height from the Liaoyanfang to the ridge(Jituan)is 17.5 chi,which is three-fifths of their horizontal distance.These results cast new light on two possible ideas for the geometric design of the roof structure.