Composite bridge steel formwork processing manufacturer: How to check the dimensional accuracy after steel formwork correction?

1、 Testing tools and methods
Testing project applicable tools and technical precision control standards
Three dimensional coordinate analysis method for laser tracker with plane position deviation
Total station grid coordinate comparison method ± 3mm/10m (GB50205 standard)
Ultrasonic thickness gauge for cross-sectional dimensions (5MHz high-frequency probe)
Caliper three-point measurement method (tolerance ± 0.5mm), thickness tolerance ± 1mm, profile height tolerance ± 2mm
Weld flatness and straightness tester (resolution 0.02mm)
Magnetic plug gauge (range 0.02-3.0mm) with weld seam height ≤ 3mm and misalignment ≤ 1mm
Angle deviation digital angle gauge (resolution 0.1 °)
3D scanning reverse modeling comparison method bending angle tolerance ± 0.5 ° (± 0.3 ° for special parts)
2、 Staged inspection process
Initial examination after correction
Using laser scanning to obtain three-dimensional point cloud data and conducting deviation analysis with the design model (allowing local deviation ≤ L/500)
Grid measurement of the correction area using a micrometer (measuring point spacing ≤ 300mm)
Preloading retest
After applying 110% of the design load for 24 hours, the deformation of key nodes is retested to be ≤ 2mm
Key monitoring of residual deformation rate in the heat affected zone (HAZ) of welds ≤ 0.15%
Final inspection before assembly
Attempt to assemble adjacent templates, with a joint gap of ≤ 1.5mm and no misalignment
Check the concentricity of bolt holes (through-hole rate ≥ 95%, misalignment ≤ 1mm)
3、 Examples of professional equipment applications
3D scanning system
Using a blue light scanner (accuracy 0.02mm/m ²), generate deviation chromatograms (red>3mm, yellow 1-3mm, green<1mm)
Verify the curvature radius of the curved formwork of the bridge (with a tolerance of R ± 2mm)
Numerical Control Testing Platform
Set up automatic measurement path and conduct dense sampling of 500 points/㎡ on the box girder template
Real time data transmission to MES system, generating SPC process control charts
4、 Qualification criteria
Measures for handling the allowable range of defect types
Local pit depth ≤ 0.5mm, area ≤ 20cm ², polished after epoxy resin repair
Wave deformation wavelength/amplitude ratio ≥ 40:1, local pressure correction+flame leveling
Verticality deviation ≤ 2mm/m, cumulative ≤ 5mm secondary adjustment of support system
Deviation of bolt hole position, concentricity error>1.5mm. Re drill after drilling or welding repair
Through the above detection system, it can be ensured that the dimensional accuracy of the corrected steel formwork meets the requirements of GB50205-2025 standard, and the qualification rate for repeated use is increased to over 98%.