BRIDGE AND PALLET CRACK DEFORMATION INSPECTION AND REPAIR (Contd)
CRACK DEFORMATION INSPECTION
Welding repair of bridge structural components is not allowed at
field level. Attempting welding repair of damaged structural areas
without proper heat treating will compromise strength of bridge.
Failure to comply may result in failure of bridge, damage to
equipment, and possible injury or death to personnel.
a. In case of a deformation, there will be an additional evaluation in view of the portion
represented within the complete structure required in order to establish the remaining
b. Basically, any deformation in the complete cross-sectional area of a component subject to
pressure load will lead to complete failure.
c. However, if a deformation limit is exceeded in areas of a profile or plate, which reflect a minor
width portion only (uncritical width), the latter may be considered negligible (crack free
d. Due to the fact that evaluation of these marginal conditions may easily lead to
misinterpretations, it is recommended to segregate the item in question in any case if and when
the critical deformation is reached and the uncritical width is exceeded.
e. In components subject to tensile loads, deformation will, normally, be uncritical (check for
non-existence of cracks).
f. Various deformations arranged in line along a longitudinal axis (crossing direction) are looked
upon as one deformation.
The inspection method is given in the inspection plan.
Table 1. Smallest Surface Crack Lengths Definitely to be Detected in Inches and mm.
Visual inspection or using x 10
0.787 in. (20 mm)
1.181 in. (30 mm)
1.969 in. (50 mm)
For smaller cracks use
0.197 in. (5 mm)
0.394 in. (10 mm)
0.591 in. (15 mm)
Personnel must observe all relevant safety precautions to prevent
inhaling toxic fumes or dust when cleaning or welding around
epoxy paints used on bridge quarters. Failure to comply may result
in injury or death to personnel.
The above rates are based on sufficient accessibility, adequate
lighting and removed surface coating.
a. Therefore, in case of a deformation detected, there must always be a crack inspection of that
area carried out as well.
b. If the deformation measured exceeds the critical deformation and the uncritical width, the
bridge quarter concerned must be put out of service immediately.
c. Further use subject to load restrictions is considered acceptable. To that end, however, there
must be an evaluation of the overall condition of the bridge quarter and of the damage details
carried out. Release for unlimited use will have to be granted by the manufacturer.