What is the principle of restoring historic buildings?

China has a long history, so there are many ancient buildings in history, which are the crystallization of the wisdom of our people and have far-reaching historical significance. However, after years of wind and rain, some ancient buildings have been damaged to some extent. Once these ancient buildings are destroyed, they no longer exist. Therefore, it is necessary to better restore and protect ancient buildings. The restoration of ancient buildings must follow the principle of restoring to the original state or maintaining the status quo. In addition, there are principles such as safety first, unified style, disaster prevention and utilization of old materials. First, the principle of ancient building repair

Ancient architecture is an effective carrier to understand history and inherit civilization. Whether it can be preserved and passed down is related to the inheritance of national culture and the development of world culture. When restoring ancient buildings, we should pay attention to the following principles:

1, safety first principle

Ancient buildings have a history of more than 100 years, and the components have to undergo different degrees of weathering or flashing. When finalizing the case, whether the building is safe or not should be regarded as one of the principles of repair.

2, the principle of unified style

The repaired parts should be as consistent as possible with the original style. Respect the original style and craftsmanship of ancient buildings and maintain historical features.

3, the principle of prevention first

Repair should focus on prevention, and ancient buildings should be regularly maintained to eliminate accumulated diseases and hidden dangers in the bud.

4, the principle of the use of old materials

Using old materials can not only save a lot of money. From the perspective of building materials, it can also retain the characteristics of the original building.

Second, the core of ancient building repair

Original cultural relics of ancient buildings: refers to the appearance of ancient buildings when they are completed (based on the age of the existing main structure) or the existing healthy appearance after being repaired by later generations. The original state of the whole building should include its original general layout, spatial combination and greening of its internal environment. Generally speaking, it refers to the original shape, original structure, original material and original technology. These four contents are indispensable.

Restitution: When maintaining ancient buildings, with sufficient scientific basis, the changed and incomplete parts in history will be restored to reproduce the true face of ancient buildings in history. Restoration must be based on the age of the existing main structure of ancient buildings. However, the restoration of changed and incomplete parts is generally limited to the building structure, and works of art such as statues, murals and sculptures should generally be preserved.

Preserve the status quo: When maintaining ancient buildings, the existing features should prevail, and the changed parts in the past repairs should be preserved to preserve the historical readability of ancient buildings. Practice has proved that there is often some internal relationship between the present situation and the original state, and the present situation is an indispensable reference for studying the original state.

1964 The Venice Charter adopted by the international conference is a law for the protection and maintenance of cultural relics that many countries abide by. The articles of association first emphasize the protection and restoration of ancient buildings, both as historical witnesses and as works of art. For the restoration work, it should be regarded as a highly professional technology, and the original data and conclusive documents must be respected, and there should be no speculation. Any inevitable addition must be obviously different from the appearance of the original building. When traditional technology can't solve the problem, new technology can be cited, but it must be proved to be effective through experiments.

Third, the common methods of repairing ancient buildings

1, basis

The common damage of ancient building foundation is mainly settlement and damage, which is mainly caused by the change of foundation bearing capacity, the influence of groundwater, the growth of tree roots, the damage of underground pipelines and external forces. When maintaining, we must first find out the reasons and eliminate these adverse effects.

The foundation repair generally adopts the method of cutting and repairing in sections, each section shall not exceed 1m, and shall not exceed 20% of the foundation bottom area. In the process of restoration, the original structure and wall must be supported and strengthened, and the scheme calculation and design should be carried out when necessary to ensure safe construction.

2. Taiwan Province base

Above the foundation is the abutment, and the common damages mainly include the loosening and displacement of the step stones, the falling off, fragmentation and bulging of the side pool board, and the brittleness and weathering of the brick side pool board. Generally speaking, the foundation stone of abutment is loose and displaced. If the components have large displacement and bulging, they need to be restored before joining, that is, reinstalled. In the case of damaged or missing stone components, stone materials with the same or similar texture and material as the original components can be used for supplement. Generally speaking, the difference between the old and the new can be handled by doing the new or doing the old as a whole.

Step 3: Floor

The interior of the abutment is a brick floor (that is, a terrace), and the damage of the brick floor is mainly broken, peeled off and uneven. Repair methods are generally divided into planing repair, local repair, overall redo, tung oil maintenance and so on. After the floor is repaired, it can be drilled and solidified with tung oil to make the floor look consistent and increase its strength. For some ground that is basically intact or has cultural relics value and is not suitable for repair, it can also be maintained only by drilling tung oil.

Step 4: walls

According to the position, function and building grade, the walls of ancient buildings are divided into dry-swinging silk seams, white brick walls, rough brick walls and simple broken brick walls, mixed water walls and stone walls. The common problems are peeling and slight damage of crisp alkali, which are generally caused by weathering, humidity or external damage. For the local peeling or damage of the wall, the surface layer can be removed first to expose the hard part of the brick. According to the depth, the wall can be cut and repaired with brick pieces or bricks according to the shape of the site, and the bonding is firm. After drying, tick off the seam to make it consistent with the whole. If the wall is inclined or cracked, it is necessary to find out the reasons and eliminate them, and at the same time, make a support plan. Then, according to the specific situation, either demolish and rebuild it or keep it in its original state, and fill it with mortar, plain cement slurry or polymer materials, and then strengthen observation.

5. Wooden frame

The damage of wooden frame mainly includes rotten roots of wooden column, splitting and breaking of column body, bending and decay of purlin, missing of bending and sagging of purlin, tilting of wooden frame, tenoning and so on. The main reasons are high humidity, heavy roof load and poor protection.

The treatment method of column root rot is generally column root inlay or pier column connection. When purlins and purlins rot, if the rotten part does not exceed the cross-sectional area of13, the method of removing the rotten part can be adopted, that is, the contact surface is planed and polished, and then the rotten part is firmly bonded with wood of the same material and fixed with nails. When the purlin section deteriorates more than 1/3, the mechanical properties of the members have been affected and must be replaced. When the wooden frame members are basically intact, but the overall structure is inclined and tenon-pulling, the method of knocking and straightening should be adopted. Sporadic wood components are damaged or missing, such as lifting, bucket, lifting and beating of the bucket arch head. The repair of the materials of long and short windows, drawer middle plates, skirts and frame materials is relatively simple, and it only needs to be replaced and refurbished.

6. Roof cover method

The repair of roof includes two parts, one is the repair of roof tile, and the other is the repair of wood base. Generally speaking, the two are carried out simultaneously.

When the roof leaks, the first thing to do is to find the leaking point. According to the location of indoor water leakage, find out the relative position on the roof vertically. After finding out the reason, clean the tile ridge first, shovel the mortar and rinse it clean, then wipe the damaged part with hemp knife ash, brush it along the edge with short brush dipped in water (commonly known as pulling water) after wiping it, and finally roll it with hemp brush dipped in green slurry with a tile knife to catch the light.

7, paint, ground warfare

The common damage modes of paint ground warfare are cracking, breakage, peeling and so on. The main reasons are wind, sun, rain and external damage.

Generally, it depends on the damage degree of ground warfare. If only the surface of the ground war is damaged and the hemp ash layer remains intact, then only the surface damaged ash layer can be removed. If the ground war is seriously damaged and local cracks are found in the wood foundation, all addresses must be removed and redone.