Some problems and solutions in the construction process of steel structure engineering (3)

Deformation of component

1. The component is deformed during transportation, resulting in dead or gentle bending, which makes the component unable to be installed.
Cause analysis:
a) The deformation produced when the components is made, generally presented as slow bending.
b) When the component is to be transported, the support point is not reasonable, such as the upper and lower cushion wood is not vertical, or the stacking site subsidence, so that the member will have dead bending or slow deformation.
c) Components are deformed due to collision during transportation, generally showing dead bend.
Preventive measures:
a) During the fabrication of components, measures to reduce deformation shall be adopted.
b) In the assembly, measures such as reverse deformation should be adopted. The assembly sequence should follow the sequence, and enough supports should be set up to prevent deformation.
c) In the process of transportation and transportation, pay attention to the reasonable configuration of pads.
a) The dead bending deformation of member is generally treated by mechanical correction. Use jacks or other tools to correct or with oxygen acetylene flame after baking correction.
b) When the structure is gently bending deformation, take oxyacetylene flame heating correction.

2. After assembling the steel beam members, the full length distortion exceeds the allowable value, resulting in poor installation quality of the steel beam.
Cause analysis:
a) The stitching process is unreasonable.
b) The size of assembled nodes does not meet the design requirements.
a) Assembly components to set up assembly table, as welding to the bottom of the member leveling, to prevent warpage. Assembling table should be each fulcrum level, welding to prevent deformation. Especially for the assembly of beam or ladder, it is necessary to adjust the deformation after positioning welding, and pay attention to the size of the node to conform to the design, otherwise it is easy to cause distortion of the component.
b) The member with poor rigidity should be reinforced before turning over and welding, and the member should also be leveled after turning over, otherwise the member cannot be corrected after welding.

3. Components arch, the value of large dry or less than the design value. When the arch value of the component is small, the beam is bent down after installation; When the arch value is large, the extrusion surface elevation is easy to exceed the standard.
Cause analysis:
a) Component size does not meet the design requirements.
b) In the process of erection, the measured and calculated values are not used

Post time: Oct-18-2021