How to Control the Splicing Accuracy of Multi-Curved UHPC Forms?

Joint precision control of multi-curved UHPC forms is the ultimate test of the artistic expressiveness of prefabricated buildings, aiming to achieve a perfect jointing effect of "visual seamlessness, structural continuity, and reliable waterproofing." Through a four-in-one control system of "precise 3D spatial measurement and control, digital pre-assembly, high-tolerance adjustment nodes, and precision on-site construction," Qinglong Group successfully kept the on-site installation and jointing errors of complex curved UHPC panels within ±2mm. In the double-curved curtain wall project of the Guangxi New Media Center, no two panels were identical; through the above technical system, Qinglong ensured the smooth and fluent appearance of the entire twisted curved curtain wall, creating a new urban landmark for Nanning.

Precise spatial coordinate measurement and control based on BIM and 3D scanning is the prerequisite for precision control. Before installation, a 3D laser scanner is used to capture the actual point cloud data of the building's main structure, which is then compared with the BIM design model to analyze structural deviations. Next, the 3D theoretical coordinates of each irregular UHPC component are imported into a total station. During installation, surveying engineers use the total station to directly set out the precise 3D coordinate points of each supporting keel on site, establishing an accurate spatial reference framework for the subsequent panel hanging. The accuracy of this step is the foundation for all subsequent work.

Digital pre-assembly technology is a key link in risk prevention. Before components leave the factory, Qinglong uses 3D scanning technology to obtain the actual point cloud model of each finished UHPC panel and performs a virtual pre-assembly against the design model on a computer. This process can identify in advance any jointing problems that may result from production or shrinkage deformation and correct them within the factory. At the same time, based on the virtual assembly results, the optimal installation sequence and fine-tuning scheme are determined for each panel, resolving unforeseeable problems before shipment and avoiding the embarrassment of panels that cannot be installed on site.

A connection node system with high tolerance adjustment capability is the core of absorbing errors. Even the most precise measurement and manufacturing involve minor errors. In the back-bolted dry-hanging system designed by Qinglong, the hangers typically feature 3D adjustment capability (adjustment of no less than ±15mm in each direction). Through details such as slotted holes and set screws, installers can precisely adjust the position of panels in three dimensions, ensuring that the edges of adjacent panels align and panel surfaces remain flush. This "flexible" connection method cleverly absorbs inevitable construction errors, providing the engineering and technical guarantee for high-precision jointing.