What exactly do the square piercing and the square fighting in the bucket frame mean? Thank you very much.

In bucket frame, purlin is a plane wood that runs through the column body, and bucket purlin is wood used between the stigma of eaves column and shaped like a railing in the girder frame. The bucket structure does not need wooden beams, but directly supports purlins with wooden columns and puts purlins on rafters. When building a bucket structure, first determine the number of purlins needed for the roof. Then according to the number of purlins, a row of columns are erected along the depth direction of the house, each column is placed on a purlin, and the purlin is covered with rafters, so that the weight of the roof is directly transferred from the purlin to the columns and then to the surface supporting surface.

In order to ensure the overall stability of several columns, two kinds of components, square-crossing and square-fighting, are also adopted. Each row of columns is traversed by purlins passing through the column bodies to form a purlin-like frame. ? At the same time, every two frames are connected by a bucket to form a stable spatial frame. From the morphological point of view, purlins in bucket structure are very similar to wooden beams in beam-lifting structure, but their functions are quite different. Wood beams play a bearing role, and purlins only play a fixed role.

Extended data

Compared with the lifting beam structure, because thick wooden beams are no longer used, less materials are used for large trees in the cross-bucket structure. At the same time, the whole roof truss can be assembled on the ground first, and then erected, which is also convenient for construction. In addition, dense columns are also convenient for installing wallboard and pouring mud walls. Therefore, during the Ming and Qing Dynasties, a large number of houses with bucket structures appeared in the middle and lower reaches of the Yangtze River.

The bucket frame is a light frame, and the column diameter is generally 20 ~ 30 cm. The square section is only 6× 12 to10× 20cm2; The purlin spacing is generally within 100 cm; Rafters are also made of fine materials. Tiles are laid directly on the rafters, without looking at boards and bricks. The roof is light in weight and excellent in shock resistance.

References:

Baidu Encyclopedia-Through Bucket Architecture