Are the layouts of ancient mansions in the north and south the same?
The form of wooden structures from ancient times to the Han Dynasty has not yet been fully understood and is still being explored. From the Banpo ruins to the Panlong City ruins of the Shang Dynasty, the Zhouyuan architectural ruins of the Western Zhou Dynasty, the ritual buildings of the Han Dynasty, and stone palaces, although there have been restoration studies, no systematic conclusions have been drawn, and only some connections can be seen. : ① The tombs of the Yin and Shang Dynasties all used well-dry structures. Although they were not commonly used by future generations, they played an important role in the history of the development of wooden structures. ② The layout of planar column grids excavated from palace sites from the Shang Dynasty to the Warring States Period are all arranged in rows vertically but often not in rows horizontally. Based on this, it can be inferred that the roof truss structure is mainly vertical frame, which was still used until the Han Dynasty. Therefore, vertical frame should be a commonly used structural form in the early period. Later, in the Liao and Jin Dynasties, the vertical frame was occasionally used to support the horizontal frame, which was an improved longitudinal frame. ③ Since the Western Zhou Dynasty, buckets have been used as components to combine columns and beams. Later, they gradually developed into a complex structural form in which arches, arches, etc. are combined into paving (see brackets) on buckets.
The earliest known record of specific structural forms is the three types of palace structure, hall structure and clustered corner beam structure in the Song Dynasty's "Zhuo Fa Shi". Based on existing examples, it can be inferred that these three structures were commonly used at least in the early Tang Dynasty. Their characteristics are described below.
The structure of the palace: The entire structure is divided into three overall structural layers in the horizontal direction: columns, paving, and roof, which are installed layer by layer from bottom to top and formed by stacking. If you are building a building, you only need to add columns and paving layers (flat seating). Houses using this structure have a rectangular plan. There are four types of land troughs, namely gold box bottom trough, double trough, single trough and divided bucket bottom trough.
Hall structure: use horizontal vertical roof trusses. Each roof truss is composed of several columns and beams of different lengths, and paving is only used on the outer eaves columns. Each two roof trusses are connected with rafters, loops, etc. to form a room. The number of rooms in each house is not limited. The roof trusses only need to have the same number of rafters and the rafters of the corresponding steps. The number and combination of beams and columns used in each roof truss can be different, so there is no need to specify the planar form. The construction of the hall structure is simpler than that of the palace structure, but it is not suitable to build multi-story houses. Building small-scale houses with a hall structure without paving is called "column and beam construction" and is widely used. Among the existing examples, there is also a form of integrated palace and hall structure, such as the main hall of Fengguo Temple, which uses columns, beams, paving and other components in three directions: vertical, horizontal and vertical, interlaced with each other to form a whole. The construction is complicated. It was never used again after Liao and Jin Dynasties.
Cluster angle beam structure: used for buildings with a perfect circle or regular polygonal plane. The angle beam on each column intersects with the center pole (leigong column) to form a round or square conical roof.
Song style cluster angle beam frame diagram
In the official architecture of the Ming and Qing Dynasties, the palace structure only has the superficial form, and is actually a hall structure, which is called "big wood style". The commonly used "column and beam style" is called "big wood style". The clustered corner beams are called "Cuanjian" and are mostly used in small pavilions.
In addition, in the Yangtze River Basin and the southeast and southwest regions, it is customary to use a bucket-type structure. It has the same horizontal and vertical roof truss as the hall structure, but the hall structure uses beams that are raised and shortened layer by layer to bear the weight of the purlins and the roof, so it is called a beam-lifting structure. The cross frame uses columns to directly support the purlins, without using beams, and the cross beams between the columns are only connecting components.
Component types: Large wood is used as structural components, which can be divided into 12 categories according to their functions. Among them, four categories: arch, ang, juetou and bucket, are paving components.
The beam-lifting structure of the Song Dynasty
According to the "Building Method", the following introduction is made:
①Shape. The inner and outer columns of the palace-shaped frame are of the same height. Above the column head is a horizontal paving layer, and above that are the beams that run through the depth of the entire house and are stacked along with the roof slope. The inner columns of the hall-shaped frame are raised, and there are no large beams that run through the depth of the entire house. Shorter beams are used to stack them between the columns.
②Column. Most of them are processed into a spindle shape, and the columns around the outer eaves have risers and side feet.
③Liang. The exposed beams are called Mingfu, and the beams covered by the ceiling are called Caofu. Some Mingfu are processed into the shape of moon beams. According to the different names of each beam's length and position, such as eave-shaped beam, Rufu, flat beam, lap beam, etc. The length of a beam is measured by the rafter frame. One rafter frame refers to the horizontal length of a rafter that is placed above two rafters. Generally, the length of a beam is the length of several rafter frames, which is called several rafters. However, the length of two rafter frames is The beams on the uppermost layer of the frame are called flat beams, the ones between the inner and outer columns are called bulging beams, and the beams one rafter long above the bulging beams are called tie beams.
④ Paving.
The brackets at the intersections of beams and columns form a paving layer, which can not only strengthen the integrity of the frame, but also cleverly absorb and transmit loads from different directions. It is an important part of the beam-lifting frame that plays a structural role.
The raised-beam frame of the Qing Dynasty
According to the "Engineering Practice" of the Qing Dynasty Ministry of Works, the following introduction is made:
The seven-purlin hard mountain large wood small frame of the Qing Dynasty
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①Shape. The Qingguan style architectural structure can be divided into large style and small style. Large-scale buildings are of higher grade and often use brackets. Some of the eaves columns and inner columns are of the same height, with the main decorative bracket layer and the upper supporting beam frame, which is similar to the Song-style palace structure, and most of them are similar to the Song-style hall structure. There are also large styles that do not use brackets and use thicker materials. Small buildings are small in scale, do not use brackets, and use less materials. However, there is no difference between large and small buildings.
②Column. Columns in a raised beam frame are named according to their position. The outermost row of columns located on the front and back eaves are called eaves columns. The columns located in the middle of the gable are called gable columns. The inner columns on the longitudinal center line of the building are called middle columns. The inner columns except the middle column are all called golden columns. . Judging from the existing buildings of the Forbidden City, it can be seen that the Ming Dynasty architectural pillars still retained the side-legged and rising practices, but it was not obvious in the Qing Dynasty.
③Liang. The main beams in each beam frame are named according to the number of purlins they support. For example, a beam that supports nine purlins is called a nine-beam beam, followed by eight beams, seven beams, and up to three beams. The length of the beam is measured in steps (that is, the horizontal distance between purlins). A beam with nine beams is eight steps long, a beam with seven beams is six steps long, a beam with six beams is five steps long, etc. In addition, there are several secondary short beams, such as the beam between the eaves column and the golden column, which are only one step long. They are called Taojian beams in large buildings and Baotou beams in small buildings. If the corridor is two steps wide, the peach tip beam is doubled in length, and is called a double step beam; at this time, there is often a short beam that is one step in length, called a single step beam. The cross-section aspect ratio of various types of beams is mostly close to 6:5, or 5:4, and the cross-section is almost square.
④Dougong. After the Yuan Dynasty, the brackets on the nodes of beams and columns gradually became smaller. Compared with the brackets in Tang and Song Dynasty architecture, the structural effect was weakened and the decorative effect was strengthened. By the Qing Dynasty, brackets had almost degenerated into decorative components.
⑤Others. The cross arms and supporting legs in the beam frame were cancelled, the longitudinal connecting members were reduced, and the loops, strings, etc. were unified into the standard practice of purlins, pads, and rafters, which is called "one purlin and three pieces."
The structural system formed by the raised beam frame played a decisive role in the development of ancient Chinese wooden architecture, and also provided reference materials for the development of modern architecture
Pass-through frame
A form of wooden frame in ancient Chinese architecture. This kind of frame directly supports the purlins with columns and has no beams. The original frame was called the frame, which was later simplified into "pass-through frame" and "pass-through frame". Fighting frame".
Schematic diagram of the bucket-type frame
The characteristic of the bucket-type frame is that a row of columns is erected according to the number of purlins along the depth direction of the house, with one purlin on each column and rafters on the purlins. Roof loads are transmitted directly from purlins to columns without beams. Each row of columns is connected horizontally by beams that penetrate the column body to form a frame. Each two frames are connected by dowels and fibers to form the space frame of a room. Dou Fang is used between the heads of eaves and columns, shaped like a lantern in a beam-lifting frame; fibrils are used between inner columns. Doufang and Xianzi often double as the keel of the attic of a house.
There is a pillar under each purlin, which is its preliminary form. Depending on the size of the house, different structures can be used, such as "three purlins, three columns and one penetration", "five purlins, five columns and two penetrations", "eleven purlins, eleven columns and five penetrations". As the number of pillars increases, so does the number of layers. After this method has developed to a more mature stage, in view of the excessive density of pillars affecting the use of the house, sometimes the original pillars are changed from the ground to every other pillar, and the pillars that do not fall to the ground are mounted on the pillars. The number of layers of columns and beams also increased accordingly. After passing through the eaves column, the piercing beams become overhanging beams, supporting the overhanging eaves. At this time, the piercing beams also partly served as beam supports. The roof of a bucket-frame house is generally flat and does not have a concave surface. Sometimes, padding tiles or increasing the laminated length of the tiles is used to slightly arch the area close to the roof ridge to achieve an effect similar to a reverse concave roof.
The practice of using columns to support the purlins in a bucket-type frame may have a certain connection with the early vertical frames and has a long history. The image of the Han Dynasty's bucket-frame houses can be seen in the portrait stones of the Han Dynasty. The bucket-type frame uses less materials. During construction, it is first assembled on the ground to form a complete roof truss and then erected. It has the advantages of saving labor and materials, easy construction and relatively economical. At the same time, the dense rows of columns also facilitate the installation of siding and the construction of mud walls.
Therefore, in the provinces in the middle and lower reaches of the Yangtze River in China, a large number of residential houses with bucket-type structures in the Ming and Qing Dynasties have been preserved. Some buildings in these areas that require larger space adopt the method of combining the bucket-type frame and the beam-lifting frame: the bucket-type frame is used on the gable part, and several of the rooms use the lifting-beam type frame. They cooperate with each other and complement each other. .
The bucket-type frame is a light-weight structure with a column diameter of generally 20 to 30 centimeters; the beam section is no more than 6×12 to 10×20 square centimeters; the purlin spacing is generally within 100 centimeters; the rafter The materials used are also finer. The tiles are laid directly on the rafters without adding viewing boards or bricks. The roof is lightweight and has excellent earthquake resistance.
Well Dry Structure
Jing Dry Structure Residential Houses in Nanhua, Yunnan
A kind of house structure that does not use columns and beams. This kind of structure is made of round logs or rectangular or hexagonal timbers stacked up in parallel layers. The ends of the timbers are interlocked at the corners to form the four walls of the house, which is shaped like the wooden fence on an ancient well. Short columns are erected on the left and right walls. Ridge-bearing purlins constitute a house.
The well-dry structure has been used in tomb coffins of the Shang Dynasty in China, and is still used in Han tombs. The earliest images and documents of dry-well houses seen so far belong to the Han Dynasty. Among the bronzes unearthed from Shizhai Mountain in Jinning, Yunnan, there is a well-dry house with a double slope roof. There is a record in "Huainanzi" that "the towers are extended along the plank road, and the chickens live in dry wells".
The well-dry structure requires a large amount of wood, and is very limited in terms of absolute size and opening of doors and windows. Therefore, it is not as versatile as the beam-lifting frame and the bucket-type frame. At present, there are only a few houses built using this structure in the northeastern forest areas and southwest mountainous areas in China. The well-dry structure residential house in Nanhua, Yunnan is an example of a well-dry structure house. It has bungalows and two-story buildings, all rectangular in plan, two rooms wide, and covered with a cantilevered roof. The roof is constructed with a short central column at the top of the left and right side walls supporting the ridge purlin. The rafters are placed on the ridge purlin and the well logs on the top of the front and rear eaves. The depth of the house is only two rafters.