Bridge steel formwork processing: How to control the deformation of steel formwork?

1、 Design optimization measures
Stiffness Enhancement Design
The main ribs are made of 16 # I-beams with a spacing of ≤ 500mm, and the secondary ribs are densely arranged with 10 # channel steel with a cross-sectional modulus of ≥ 401.4cm ³
Pull screw diameter ≥ 16mm, spacing ≤ 450mm, pre tightening torque ≥ 200N · m
Pre deformation compensation
Pre set anti arch amount in the weld area (plate length L/800~L/1000)
Reserved expansion joints for the long side template, with compensation calculated at 0.015mm/(m ·℃)
2、 Construction process control
Strengthening the support system
Vertical spacing between poles ≤ 1.2m, horizontal spacing ≤ 1.5m, diagonal brace angle 45 °± 5 °
Foundation bearing capacity ≥ 150kPa, laying 20mm thick steel plate for stress diffusion
Dynamic Load Management
Layered pouring height ≤ 500mm, vibrating rod insertion spacing ≤ 400mm
Preloaded with 120% of the design load for 24 hours, with a deformation exceeding 2mm, immediately reinforced
Welding process control
Adopting jump welding technology, with each weld seam length ≤ 300mm and interlayer temperature ≤ 150 ℃
Welding current grading control (plate thickness 8mm: 130-170A, 10mm: 170-210A)
3、 Deformation correction technology
Applicable scenarios of correction method process parameters
Mechanical correction hydraulic jack applies pressure>1.2 σ s, local bending deformation ≤ 15mm
Flame correction linear heating temperature 650 ± 50 ℃ wave deformation/overall distortion
Cold work correction hammer impact energy ≤ 50J/cm ² angular deformation/joint misalignment
4、 Monitoring and acceptance
Real time monitoring indicators
Laser displacement sensor monitors template deflection, with a warning value set to L/500
Infrared thermal imager detects weld temperature gradient ≤ 80 ℃/m
Acceptance criteria
Plane position deviation ≤ ± 3mm, verticality ≤ 2mm/m
Joint gap ≤ 1.5mm, adjacent board height difference ≤ 1mm
Through the above control system, the deformation of steel formwork construction can be reduced by 60% -80%, and the qualification rate of concrete forming can be increased to over 98%.