How to Control the Splicing Precision of Multi-Curved UHPC Forms? Millimeter-Level Coordination and Qinglong Group's Site-Wide Measurement System

Joint precision control for multi-curved UHPC forms is the ultimate test that determines their final visual smoothness and system performance, requiring a full-process closed-loop control system of "design pre-control, high-precision production, measurement feedback, and adjustable installation." Qinglong Group sets the overall joint precision targets for such projects at: adjacent panel joint width deviation ≤±1.5mm, panel surface misalignment ≤1.0mm, and cumulative error of continuous transitions on complex curved surfaces (within 30 meters) ≤±5mm. In the 120,000-square-meter wavy double-curved roof project of the Hainan International Convention and Exhibition Center, we used the above system to install 28,700 specially shaped panels, achieving a "seamless" visual effect. Precision control is a meticulous battle fought from start to finish with data as the yardstick.

Design Stage: Tolerance Allocation and Coordination Based on Manufacturing and Installation

Precision control begins with design. In the BIM model, we assign each component reasonable manufacturing tolerances (e.g., dimensions ±1mm), installation tolerances (e.g., positioning ±2mm), and thermal deformation allowances. Through virtual pre-assembly of the 3D model, we check and optimize the panel division scheme to avoid hard-to-adjust "dead points." Higher precision grades are set for key control points (such as boundaries and transitions).

Production Stage: Factory Quality Inspection to the "Digital Twin" Standard

High-precision molds are a prerequisite, but deviations can still occur during component production due to material shrinkage and curing deformation. We use 3D laser scanners to conduct full-size inspection of each (or sampled) component before shipment, generating point cloud data that is compared with the original design model to produce "deviation color maps." Components exceeding tolerance are reworked or downgraded to ensure only qualified products are shipped to the construction site. We require the key dimension pass rate of shipped components to be above 99.5%.

Surveying and Setting Out: Building a High-Precision Spatial Reference Framework

Before on-site installation, a high-precision 3D control network unified with the design model is established using surveying robots (such as the Leica TS60). Installation positioning points are set out on the main structure, and their own accuracy must be within ±2mm. For complex curved surfaces, traceable targets are set on the structure in advance to serve as spatial references throughout the entire installation process.

Installation and Adjustment: Smart Connection Systems with "Fault Tolerance" and "Fine Adjustment"

No matter how precise the components and measurements are, the connection system is what ultimately delivers precision. We use 3D adjustable connectors (typically allowing ±10mm or more of adjustment in each of the X/Y/Z directions), making it possible to absorb various unavoidable errors on site. Guided by total stations, installers can intuitively adjust components to their theoretical positions, keeping errors at the millimeter level. After installation, another 3D scan is carried out to produce the final as-built model, which serves as the basis for acceptance and maintenance.

Therefore, ultra-high-precision jointing is not a "miracle" achieved in any single step, but a demonstration of the capability of the entire system—from digital design to industrial production to precision construction. By investing in advanced equipment, establishing strict standards, and cultivating professional teams, Qinglong Group possesses the complete capability to master the precision challenges of multi-curved UHPC forms.