The on-site assembly efficiency of modular construction is a core factor determining its overall construction speed. This efficiency is influenced by multiple factors, including the standardization of construction processes, connection node design, hoisting techniques, on-site management, component precision control, parallel operation capabilities, and environmental adaptability. These factors are interconnected and collectively determine the overall efficiency of modular construction, from component transportation to final assembly.
Standardized construction processes are fundamental to improving assembly efficiency. Modular construction breaks down buildings into standardized components, ensuring a high degree of uniformity in the dimensions, interfaces, and installation steps of each module. Construction workers can follow fixed procedures, reducing adjustment time due to component differences. For example, using standardized bolt connections eliminates tedious on-site measurements and drilling, significantly shortening the installation time for individual modules. Standardized processes also reduce the skill requirements for workers, allowing for quick mastery of operating methods through training, further improving efficiency.
The rationality of connection node design directly affects assembly speed and safety. Modular construction requires reliable connection methods to achieve structural integrity. While traditional welding or bolt connections are mature, they are time-consuming. Modern processes utilize pre-embedded connectors or snap-fit structures, such as spring-locking mechanisms or quick-installation systems, achieving a "plug and lock" installation effect, reducing the operation time for a single node from minutes to seconds. Some designs also integrate waterproofing and sound insulation functions, reducing subsequent repair work and further improving efficiency.
The precision and safety of hoisting technology are key to assembly efficiency. Modular construction components are typically large and heavy, requiring large lifting equipment for transport. Hoisting plans must be customized based on module size, weight, and site conditions to ensure reasonable lifting point locations and compatible slings. For example, long modules require multi-point hoisting or specialized scaffolding to avoid deformation due to uneven stress; high-rise buildings require tower cranes or luffing cranes to ensure precise module placement. Stability control during hoisting, such as adjusting module angles using traction ropes, can also reduce repeated adjustments.
On-site management and collaborative work capabilities are guarantees of efficiency. Modular construction assembly involves multiple trades working simultaneously, requiring scientific scheduling to achieve optimal resource allocation. For example, foundation construction and module transportation can be carried out in parallel, but precise coordination of timelines is crucial to avoid module delays due to incomplete foundations. Temporary storage and assembly areas must be set up on-site, and logistics channels must be planned to reduce component handling distances. Furthermore, using information management tools, such as construction simulation software or IoT positioning systems, allows for real-time monitoring of module location and installation progress, timely conflict resolution, and improved overall efficiency.
Component precision control is a prerequisite for assembly efficiency. During factory prefabrication, modular construction components must be manufactured using CNC machining equipment to ensure dimensional tolerances are within a very small range. Excessive dimensional deviations require additional adjustments or even rework during on-site assembly, severely delaying progress. For example, the flatness of the splicing surfaces of wall modules must be controlled to the millimeter level; otherwise, it will lead to difficulties in installing sealing strips or excessive gaps. Therefore, factories must establish a strict quality inspection system, sampling each batch of components to ensure compliance with design requirements.
Parallel operation capabilities can significantly shorten the construction period. Modular construction supports the simultaneous assembly of multiple modules; for example, after the bottom module is fixed, the upper module can be immediately hoisted, forming a three-dimensional cross-operation. This model relies on precise construction simulation and on-site coordination to avoid work stoppages due to spatial conflicts. For example, a commercial complex project used BIM technology to simulate the assembly process, identifying and resolving collision issues in advance, thus reducing on-site assembly time.
Environmental adaptability is an external factor affecting efficiency. Although modular construction completes most of the processes in the factory, on-site assembly is still constrained by weather, geological, and other conditions. For example, rainy days may cause muddy ground, affecting the stability of lifting equipment; strong winds may necessitate the suspension of high-altitude operations. To address such issues, the construction team needs to develop contingency plans, such as erecting rain shelters and reinforcing temporary supports. Furthermore, the lightweight design of modular construction (such as using aluminum alloy frames) can reduce foundation requirements, decrease on-site processing time, and improve adaptability.
