4201 RUCKER AVE COMMUNITY HEALTH CENTER 2019-04-10

Steel See General Structural notes Building Description The building was constructed in 1973 and is a steel framed building with substantial brick masonry exterior walls and brick masonry spandrels that wrap floor beams at the exterior. Steel columns are also wrapped with brick masonry. Original construction drawings for the building indicate that the lateral load resisting system for the building is a frame system consisting of welded steel moment connections of steel beams to steel columns. Generic typical moment connection is shown as a beam top flange plate welded to the column flange however specific connection details are delegated to the fabricator. This type of welded moment connection was found to have significant deficiencies after the 1994 Northridge, California earthquake and is not allowed under current steel moment frame design. While the masonry spandrels and masonry walls add stiffness to the building,the masonry is not detailed to act as lateral load resisting elements for the building. Due to the inherent flexibility of the steel frame of the building,the masonry is subject to potential serious damage during an earthquake and may pose a safety hazard to building occupants. The seismic volunteer retrofit strategy consists of the installation of steel concentrically braced frames (SCBFs)with drag struts that will take the building code lateral loads(including loads from masonry elements). The SCBFs will significantly reduce demands on steel frame moment connections and significantly reduce diaphragm loads to the brick masonry elements of the building. The reduced demands to frame elements and loads to masonry will reduce structural and non-structural damage to the building in the event of an earthquake and improve the life-safety performance of the building. Swenson Say Faget, Inc. Structural Engineering ? 2124 Third Avenue,Suite 100,_Seattle WA 98121 Ph:(206)443-6212 Fax (206)443-4870 `)