Hybrid structure
Mixed structure: Houses with brick or block walls, reinforced concrete or prestressed concrete floors. Because of its simple construction and low cost, it is the most widely used structural form; But the self-weight is larger, and the seismic performance of the wall is poor, in order to improve its seismic performance, the reinforced concrete structural column is added at the junction of the inner and outer walls and the corner of the outer wall, also called the seismic column. The structural columns are connected with the ring beams of the floor and roof to improve the integrity, strength and deformation ability of the house. If the wall is built with hollow blocks, steel bars can be inserted into the block holes that penetrate up and down, and concrete is poured into the holes to form reinforced concrete columns to increase the earthquake resistance of the house.
Prefabricated slab structure
The prefabricated slab structure is a building structure with a high degree of industrialization developed after the Second World War. The main advantages are that it can be commercialized, the on-site construction efficiency is high, the labor intensity is low, the dead weight is light, and the structural strength and deformation capacity are better than that of the mixed structure. However, the cost is high, and large-scale transportation and hoisting machinery is required, and the plane layout is not flexible enough. Wall panels are divided into interior wall panels and exterior wall panels according to building functions. Interior wall panels are mainly used as load-bearing components and are made of a single material. Exterior wall panels are generally non-load-bearing wall panels, which have the functions of heat preservation, heat insulation, waterproofing, etc., and the structure is relatively complex, and some are made of composite wall panels with a variety of materials. According to the different materials used, wallboard is divided into concrete hollow wallboard, solid wallboard, light aggregate concrete wallboard, industrial waste concrete wallboard, vibrating brick wallboard, etc. The construction of prefabricated slab structure is the key to whether the house can give full play to its strength, ensure the necessary stiffness and the overall performance of the space. Ways to strengthen the connection:
(1) Welding the steel bars protruding from the upper and lower wall slabs and adjacent floor slabs;
(2) The four sides of the wall and the floor slab are equipped with tooth grooves to increase the ability of the joint to transmit shear force;
(3) Pour the joints into a whole with concrete. It is also used to add vertical prestress to the wall and connect the floor slab and the wall slab into a whole.
Calculation of internal forces: The strength of wall slabs, floor slabs and their joints under vertical and horizontal loads should be calculated. Analysis of the internal force of the wall: when the vertical load and the horizontal load outside the plane are acted, the wall is calculated according to the vertical members supported by the roof and the foundation with immovable hinges at both ends; When the horizontal load acts in the plane, the wall is calculated according to the vertical cantilever structure embedded in the foundation, and the influence of the joint work of the longitudinal and transverse walls and the influence of the wall opening size are considered simultaneously.
Cast-in-place wall panel construction
Cast-in-place wall panel structure: The wall is cast-in-situ with concrete, and the floor slab is prefabricated or cast-in-situ house structure. The main advantage is good seismic performance. Compared with the mixed structure, the amount of wall plastering is greatly reduced, the labor intensity is reduced, and the amount of labor is less; Compared with the prefabricated slab structure, it is easy to construct and has developed rapidly, and has become one of the main structural forms of multi-storey and high-rise residential buildings in China's earthquake areas. The wall materials and construction methods of cast-in-place wallboard structure can be divided into cast-in-place concrete for internal and external walls and cast-in-situ for transverse walls and internal longitudinal walls, and the exterior walls are made of prefabricated slabs (referred to as internal pouring and external hanging) or bricks and blocks (referred to as internal pouring and external masonry), and the cast-in-place wall can be constructed by shaping templates (large templates, combined templates, tunnel formwork templates) or by sliding formwork and mold lifting methods. The floor slab is made of cast-in-place concrete floor slab, prefabricated strip slab or whole slab, and the floor slab should be made into continuous slab to improve the integrity of the house. The wall panel structure of internal and external masonry should be built first and then poured concrete inner wall to ensure that the internal and external walls are well combined.
Calculation of internal forces: Under vertical loads, the internal forces are distributed according to the area ratio of the cross-section of the vertical and horizontal walls. When the transverse horizontal force acts, a part of the outer longitudinal wall can be used as the effective flange of the transverse wall, and the calculation graph can be simplified to a frame, each wall limb of the transverse wall is used as the frame column, the connecting beam of the transverse wall is used as the frame beam, and the floor slab is used as a hinged connecting rod, and the transverse horizontal force is calculated according to the common work of all the transverse walls. When the longitudinal horizontal force acts, the transverse wall participates in the work, and the structure works together along the longitudinal longitudinal space structure system composed of longitudinal and transverse walls, and the calculation figure can be simplified into a composite frame composed of internal and external walls, the connecting beams of the outer longitudinal wall are used as frame beams, and the wall limbs and transverse walls of the longitudinal wall form frame columns. If the interior and exterior wall materials are different, the thickness of the exterior wall should be converted according to the ratio of the elastic modulus of the exterior and interior wall materials.
