Steel Framed Parking Garage Corrosion Assessment, Structural Analysis, and Shoring Repairs

摘要

WJE performed a structural analysis and designed splint shoring repairs for a parking garage at a university in Connecticut. The garage was built in 1974, and the original design specified a steel framed structure with nonstandard girder-to-column moment connections. The girders laterally brace the columns in the north-south direction at each slab. Lateral stability in the east-west direction is provided by 'K' bracing. During a routine inspection, WJE observed deformation of the column webs and flanges at the moment connections, a significant tilt in the columns, and severe corrosion of many steel members throughout the garage. An assessment of all steel columns and girders was performed, which included section loss measurements. To better understand the behavior and stresses in the garage, representative areas of the structure were modeled in CSI SAP2000 and Autodesk Simulation Mechanical finite element analysis software. The finite element model of a typical moment connection served to locate points of high stress in the connection, particularly at the bolts and welds. In combination with the finite element model, the SAP model provided better understanding of the behavior of the gravity system and the utilization ratios of the columns. Columns with critical utilization ratios and severe section loss were selected to receive atypical splint shoring repairs. WJE's repair design accounted for significant axial loads in the columns and moment transfer at the existing beam-column connections.