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HomeMy WebLinkAboutLetter from Engineer 07.19.2014KURTZ & ASSOCIATES. INC. 5012 County Road 154 Glenwood Springs, CO 81601 STRUCTURAL CONSULTANTS Phone (970) 945 6305 Fax (970) 945 1093 MEMORANDUM To: Garfield County Building and Planning Department 108 Eight Street Glenwood Springs, Co. Re: ECOS Commercial Building: Summary of Field Inspections 6690 Highway 82, Garfield County, CO. July 19, 2014 Kurtz & Assoc., Inc. is the structural engineer of record for the noted commercial building. The building footprint is 40'-0" north -to -south by 103'-8" east -to -west. The large, walk -out basement type structure building is a two story structure which occupies a relatively steep site. Consequently, the floor -to -floor height from the lower level to the main level is 14'-6". The lower level floor is a concrete slab -on -grade. Brian Kurtz, P.E. of Kurtz & Assoc., Inc. performed the following structural inspections during the course of the construction: A. Feb. 22, 2013: Inspected the foundation during construction. At that time the footings had been poured and forming for the perimeter foundation walls was in progress. Footing sizes, and dowel size and spacing was verified to be in conformance with the structural documents. B. July 08, 2013: Inspected the upper floor framing. The upper floor system consists of a 3" thick concrete slab placed on corrugated steel form deck over 12" deep light gage steel 'C' joists spaced at 12" on center. The 'C' joists span approximately 20'-0" and are supported on 18" deep (W18's) wide flange, structural steel beams. The south edge of the upper floor, and subsequently the south exterior wood stud bearing wall, are supported by 12" deep (W12's) wide flange, structural steel beams. The W12's span approximately 20'-0" in concert with the floor joists and are supported by structural steel columns. The framing system was designed so that the lower level walls along the south side of the building were not load bearing walls. The beams and columns along the south wall from grid '4' to '6' were designed as a rigid frame to resist lateral loads given the absence of any structural walls on this side of the building. At this time the specified beam -to -column welding necessary to create the rigid frame was not fully complete: the beam to column welding at grid line '6' was yet to be implemented, and the beam -to - column welding at grid line '4' was incomplete. This welding was completed and re- inspected by our office on Sept. 06, 2013. (2) C. Sept. 06, 2013: Inspected the upper level, exterior, wood stud bearing walls, the upper level, interior, wood stud shear walls and the roof framing. The roof framing system utilizes pre -manufactured roof trusses spaced at 24" on center spanning 40'-0" north -to -south. Two significant structural changes were addressed at this time: 1. The roof overhangs overhang on the south, east and west sides of the building were increased to 4'-0". 2. The conventional wood stud bearing walls with structural headers at window openings was revised, in part, to incorporate continuous polycarbonate wall panels. These two revisions were addressed by our office at that time, and were incorporated into the structural documents on July 31, 2014. D. June 24, 2014: Inspected the repair of a concrete corbel on grid line '6'. The corbel supports the north end of the W18 steel floor beam. The concrete had cracked during construction at this location. A triangular steel bracket had been epoxy bolted to the end of the concrete wall and a 3" high steel strap had been extended from the bracket across the corbel and crack and bolted into the sound concrete wall. The strap is located near the bottom of the 12" high bracket. I recommended that a second horizontal strap be installed near the top of the bracket, and in a manner similar to the initial strap, extended across the crack, and bolted to the sound concrete and welded to the vertical steel plate. At this time I also noted that a wind load resisting hold-down anchor had not been installed. The anchor attaches the south end of the upper level, interior, wood stud wall on grid line '5' to the W18 steel floor beam. I recommended that the hold-down be installed in accordance with the structural documents. E. July 25, 2014: Re -inspected the grid line '6' concrete corbel repair, and verified that the hold-down anchor on grid line '5' was installed. The'completed corbel repair is structurally acceptable. The hold-down was installed as specified. CONCLUSION: At this time the structural elements of the building have been substantially completed in a professional manner, and are in accordance with the structural documents.