Structural Diagram of Large-Span Prefabricated Houses

Currently, it is not possible to directly provide a structural diagram of large-span prefabricated houses, but the design key points and typical solutions can be explained in conjunction with relevant structural information. The core of large-span prefabricated house structures lies in achieving efficient load-bearing through the rational combination of prefabricated components. Common solutions include prestressed double-T slab structures and floor selection within a span range of 20-50m, as detailed below:

Prestressed double-T slab structures are typical representatives of prefabricated large-span houses. They are horizontally spliced from a wide slab surface and two tall, narrow ribs, resembling two letter 'T's placed side by side. The slab surface serves as a horizontal load-bearing component and simultaneously as the compression zone for the longitudinal load-bearing ribs, forming a clear load transfer path: loads are transferred from the slab surface to the ribs on both sides and then downward to the supporting structure. This geometrically simple design reduces material redundancy while enhancing crack resistance through prestressing technology, making it an ideal choice for large-span floors. According to China's 'Atlas of Prestressed Concrete Double-T Slabs' (SG432-1-3), standard double-T slabs can have rib heights up to 960mm, slab widths of 2.4m, and maximum spans of 23.9m, suitable for industrial plants, warehouses, and other scenarios requiring large coverage areas. Their advantages lie in high component standardization, fast construction speed, and low overall cost, but attention must be paid to the design of connection nodes between the slab surface and ribs to avoid local stress concentrations.

For large-span floors with spans ranging from 20-50m, appropriate prefabricated solutions must be selected based on the specific span range:

• When the span L ∈ [20m, 25m), options include reinforced concrete open-web truss floors, reinforced concrete open-web girder floors, and planar steel truss floors. Among them, the reinforced concrete open-web truss floor forms a spatial grid through upper and lower chords and web members, utilizing the compressive strength of concrete and the lightweight nature of the open-web structure to reduce self-weight, suitable for buildings with moderate spans and high clear height requirements; the planar steel truss floor, primarily made of steel, disperses loads through a truss system, featuring light self-weight and short construction periods, but requiring consideration of corrosion protection.
• When the span further increases, more efficient load-bearing systems must be adopted, such as steel-concrete composite beam floors (combining the tensile strength of steel with the compressive strength of concrete) or reinforced concrete waffle floors (dispersing loads through a bidirectional beam system). However, these solutions often rely on on-site pouring, and their compatibility with prefabrication trends must be evaluated based on project requirements.

When designing large-span prefabricated structures, three key points must be focused on: first, the standardization and modularization of components to reduce production costs; second, the reliability of connection nodes to ensure smooth load transfer between prefabricated components; third, the overall structural stability to avoid excessive lateral displacement due to large spans. In practical applications, comprehensive selection must be made based on building functions, load conditions, and construction conditions.