archeng59
Structural
- Aug 24, 2005
- 620
thread507-508096
I read the referenced thread regarding some 10x10 tubes with a crack in the corner. I was asked to look at some 4x4x1/4 tubes in a building that is not my design. The tubes are used as hangers for an elevated running track in a wellness center. New construction. The steel framing has been in place for about a year. The contractor noticed the cracks after the steel framing was painted a light gray. There is some sidewall bulging adjacent to the crack. No connections are near the crack, which is located about 4 ft from the end of each tube.
The first thought was the crack was caused by freezing water but the contractor said the tubes were not stored on-site during cold weather. The fabricator said the tubes were shipped to the job site shortly after being received, cut to length and slots cut for gussets at each end. The fabricator said the tubes were not stored at their shop during cold weather. So, freezing water inside the tubes does not appear to be a cause unless it happened at the mill.
My thought is the cracks formed when the tubes were formed and the cracks were not noticed until after the tubes were painted gray. I checked the capacity of the tubes versus loading and they are nowhere near being over-stressed.
Are the tubes still ok to remain in place since they have adequate capacity to support the imposed loads? In my opinion, yes, but would like another opinion. Can the cracks be repaired? I'm concerned about welding the cracks closed and causing other problems.
I read the referenced thread regarding some 10x10 tubes with a crack in the corner. I was asked to look at some 4x4x1/4 tubes in a building that is not my design. The tubes are used as hangers for an elevated running track in a wellness center. New construction. The steel framing has been in place for about a year. The contractor noticed the cracks after the steel framing was painted a light gray. There is some sidewall bulging adjacent to the crack. No connections are near the crack, which is located about 4 ft from the end of each tube.
The first thought was the crack was caused by freezing water but the contractor said the tubes were not stored on-site during cold weather. The fabricator said the tubes were shipped to the job site shortly after being received, cut to length and slots cut for gussets at each end. The fabricator said the tubes were not stored at their shop during cold weather. So, freezing water inside the tubes does not appear to be a cause unless it happened at the mill.
My thought is the cracks formed when the tubes were formed and the cracks were not noticed until after the tubes were painted gray. I checked the capacity of the tubes versus loading and they are nowhere near being over-stressed.
Are the tubes still ok to remain in place since they have adequate capacity to support the imposed loads? In my opinion, yes, but would like another opinion. Can the cracks be repaired? I'm concerned about welding the cracks closed and causing other problems.
