Remove SOMD and Structural Steel Install for Additional Reinforced SOMD
Apr 28, 2021
10
| STATEMENT OF PROBLEM: CCC was tasked to remove a slab on metal deck (SOMD) on the first floor of the hospital for installation of new structural steel to provide a stronger SOMD for the MRI machine to be installed. CCC marked the slab removal per the drawings and had the SOMD shored from below with 2 additional layers of plywood so we could cut the slab and remove the pieces in large sections. After removal of all slab sections per the architectural print, the last few slabs that were removed were cut on the incorrect side of the supporting beam below. This left a section of SOMD "hanging" when we lowered most of the shoring below to install the structural steel. Existing steel was measured for fabrication of new steel reinforcement installation. Fabrication Shop used their original shop drawings and not field measured marked up drawings for fabrication. COURSE OF ACTION: CCC discussed the best course of action with the Structural Engineer of record and came up with a solution that was acceptable for the situation. The structural steel that was fabricated was too short due to fabricating off the shop drawings and would not be able to be field adjusted. The fabrication shop got the corrected pieces to the field the following day. LESSON FOR FUTURE PROJECTS: When removing SOMD in the future, pre-drill holes from below so we can mark where the existing steel is. Using measurements are a good approach but if we would have predrilled from below going up we would have been able to see that we were on the incorrect side of the beam structurally. While the cut line was drawn incorrectly on the print we could have been more thorough than measuring and tracing on the floor to be removed. The structural steel fabrication team needs to double check to make sure field measurements were not done and to make sure they fabricate with the most current information available as to not have a mishap when it is infill of existing steel. |
