How to Control the Jointing Precision of Multi-Curved UHPC Shapes? Precision Standards and Control Solutions

For multi-curved UHPC shapes, with surfaces bending in multiple directions and complex spatial forms, splicing precision directly affects the smoothness of the overall shape and structural stability, requiring precise splicing achieved through refined whole-process control. Drawing on its experience from the double-curved UHPC project of the Guangxi New Media Center, Qinglong explains splicing precision standards and core control measures.

I. Core Precision Standards for Multi-Curved Surface Splicing

Define clear precision indicators as the basis for control. Splicing gap precision: the width of splicing seams between adjacent UHPC components must be controlled within 6-10mm, with an error ≤±0.5mm; for double-curved special-shaped components, due to large curvature variation, gaps of 10-12mm should be reserved to ensure sealing and deformation space; surface flushness requirements: the height difference between adjacent component surfaces must be ≤0.8mm, inspected with a 2m straightedge combined with a feeler gauge, with no obvious step feel, and the flatness deviation of the overall curved surface within every 10m range must be ≤3mm; curvature consistency requirements: after splicing, the curved surface is compared with the design model, with curvature radius deviation ≤2mm, to avoid local splicing misalignment that would distort the shape; in the Hainan Poly Peninsula No. 1 project, Qinglong achieved curvature deviation ≤1.5mm through precise control.

II. Core Factors Affecting Splicing Precision Deviation

Precisely identify influencing factors for targeted control. Component production errors: insufficient mold precision and curing deformation during factory production cause dimensional deviations of components; production errors must be controlled within ≤±1mm, and Qinglong has achieved zero exceedance of production precision tolerances through digital mold technology; installation positioning deviations: insufficient precision of on-site measurement tools and inaccurate baseline setting cause component positioning deviations, especially since multi-curved spatial positioning is difficult and prone to 3D coordinate offsets; environmental factors: high temperature and strong wind can cause thermal expansion and contraction of components or swinging during installation, affecting splicing precision, so a suitable construction environment must be selected (temperature 5-35°C, wind force ≤ level 5).

III. Core Implementation Measures for Splicing Precision Control

Whole-process control ensures precision meets standards. Factory production precision control: Rhino+CNC digital mold technology is adopted to ensure the dimensional and curved surface precision of components, with 3D scanning inspection performed on each piece before leaving the factory, and unqualified products are strictly prohibited from leaving the factory; on-site installation baseline setting: a high-precision measurement control network is established, using a total station and laser tracker to create 3D positioning baselines, monitoring component installation positions in real time; in the Shanghai New World project, Qinglong achieved 3D coordinate positioning error ≤±1mm with this technology; splicing process optimization: a "position first, then fix" process is adopted, using adjustable connectors to temporarily fix components and shims to fine-tune positions, with permanent fixing after precise placement; multi-curved splicing adopts a "segmented splicing, overall calibration" approach to avoid accumulated errors.

IV. Splicing Precision Inspection and Rectification Plan

Strict inspection and timely rectification guarantee splicing results. Real-time inspection methods: 3D laser scanning technology is adopted, and after each component is spliced, it is immediately scanned to compare deviations from the design model for timely adjustment; overall precision inspection: after all components are spliced, an overall curved surface scan is performed to check overall flatness and curvature consistency, ensuring compliance with design requirements; deviation rectification measures: minor deviations (≤1mm) can be corrected by grinding component edges or adjusting sealant thickness; moderate deviations (1-2mm) require loosening connectors for repositioning; severe deviations (>2mm) require component replacement. Qinglong has established a graded deviation rectification mechanism to ensure precision at all splicing locations meets standards.