《营造法式》之四耳斗里壁隔口包耳作用研究

Study on the role of connectivity of the Dou's ears by each side of the gap of the Dou with four ears from Yingzao-fashi

摘要:

《营造法式》卷四大木作制度规定了“凡四耳斗，于顺跳口内前后里壁各留隔口包耳”，并给出华栱开栱口之法：“华栱于底面开口，深五分，广二十分”。使华栱在构造上能够与隔口包耳相匹配。然而，隔口包耳与华栱之栱口尺寸并不严密吻合，二者之间存在尺寸间隙。通过文献调查，发现已有的文献对隔口包耳的作用及尺寸间隙问题观点不一，存在模糊认识，甚至忽视了尺寸间隙的存在。针对上述问题，在对斗耳、隔口包耳受力机制分析的基础上，结合工程施工安装的实际，厘清了尺寸间隙的原因，指出隔口包耳的作用是对斗耳的拉结加固。并从地域性传统木构建筑中“斗”的隔口包耳退化，以及斗耳的高度减小的流变过程，进一步实证了隔口包耳与斗耳高度存在受力机制上的联系。

Abstract:

The Yingzao Fashi system stipulates that “All four ears should be separated into the inner wall and the inner wall of the mouth”, and gives the method of opening the mouth of Huachong: “Huachong opens at the bottom, deep 5 minutes, wide 20 minutes”. The structure of hua-gong can match with the diaphragm ear. However, the size of the diaphragm ear and the Huachong chi-kung mouth does not exactly match, and there is a size gap between the two. Through literature investigation, it is found that there are different opinions on the function of the diaphragm ear and the size gap in the existing literature, and there is fuzzy understanding, even ignoring the existence of the size gap. In view of the above problems, based on the analysis of the force mechanism of the bucket ear and the diaphragm ear, combined with the actual construction and installation of the project, this paper clarifies the reason of the size gap, and points out that the diaphragm ear is the tie reinforcement of the bucket ear. It is further proved that there is a mechanical relationship between the gap ear and the height of the bucket ear from the degradation of the gap ear and the rheological process of the height reduction of the bucket ear in the regional traditional wooden building.