I. Classification and characteristics of buildings 1. Civil buildings: houses for people to live, live and engage in various cultural public welfare activities. According to their different uses, there are the following two types: (1) residential buildings: buildings for people's daily life, such as houses, dormitories, hotels, guest houses, etc. (2) Public buildings: buildings for people to engage in social public activities and buildings with various welfare facilities, such as various schools, libraries and theaters. 2. Industrial buildings: the general name of various buildings and structures for people to engage in various industrial production activities. These production buildings are often called industrial workshops. Including workshops, substations, boiler rooms, warehouses, etc. Second, according to the classification of building structural materials 1, brick-wood structure: the main load-bearing component of this kind of house is brick-wood structure. Among them, the vertical load-bearing components such as walls and columns are made of bricks, and the floor and roof truss of horizontal load-bearing components are made of wood. This kind of structure has fewer floors and is mostly used in single-storey houses. 2. Brick-concrete structure: the walls and columns of the building are made of bricks, and the beams, floors, stairs and roofs are made of reinforced concrete, thus becoming a brick-concrete structure. This structure is mostly used in civil buildings and small industrial workshops with fewer floors (less than six floors), and it is a widely used structural form at present. 3. Reinforced concrete structure: the beams, columns, floors and foundations of the building are all reinforced concrete. Beam, floor, column and foundation form a load-bearing frame, so it is also called frame structure. The wall only plays the role of enclosure and is made of bricks. This structure is used for high-rise or long-span buildings. 4. Steel structure: beams, columns, roof trusses and other load-bearing components of the building are made of steel, and the walls are made of bricks or other materials. This structure is mostly used in large industrial buildings. Three. According to the bearing mode of building structure 1. The transmission mode of load-bearing wall structure is: the weight of the roof is borne by the roof truss (or beam column), which is supported on the load-bearing wall, and the weight of the floor is supported on the load-bearing wall by the beams and plates that make up the floor. Therefore, the load of the roof and floor is borne by the load-bearing wall; There is a foundation under the wall, and there is a foundation under the foundation. All loads are transferred from the wall and foundation to the foundation. 2. The main load-bearing system of frame structure is composed of beams and columns, but the beams and columns are rigidly connected (in reinforced concrete structures, concrete is usually poured after the steel bars at the ends are welded into a whole), thus forming an integral rigid frame (or frame). Generally, multi-storey industrial workshops or large high-rise civil buildings are mostly frame structures. 3. The main load-bearing system of bent structure consists of roof truss and columns. The roof truss is hinged at the top of the column (usually welded or bolted), and the lower end of the column is embedded in the foundation. This method is mostly used in general single-storey industrial workshops. 4. Other high-rise and super-high-rise buildings need to be built due to urban development. The above structural forms are not enough to resist horizontal loads (wind load and earthquake load), so shear wall structure system and bucket structure system are developed. Four. Classification of building height buildings can be divided into the following categories according to the number of floors: 1, and low floors: 2 floors and below; 2. Multilayer: more than 2 layers and less than 8 layers; 3. Middle and high floors: above 8 floors and below 16 floors; 4. Floor height: 16 above and 24 below; 5. Super-high floor: more than 24 floors.