Laserfiche WebLink
C SFA Design Group, LLC <br /> Sfd STRUCTURAL. I GEOTECHNICAL I SPECIAL INSPECTIONS PROJECT NO. SHEET NO. <br /> MFR22-156 <br /> PROJECT DATE <br /> Kobuke Residence Underpinning 8/19/2022 <br /> SUBJECT BY <br /> Push Pier Design Requirements MEK <br /> Structural Narrative <br /> The structural calculations and drawings enclosed are in reference to the design of the foundation underpinning of the 1-story <br /> residence located in Everett,WA as referenced on the coversheet.The round steel tubes and retrofit brackets are used to <br /> stabilize and/or lift settling foundations.The bottom and back portion of the bracket is securely seated against the existing <br /> concrete footing. Using the weight of the existing structure, pier sections are continuously hydraulically driven through the <br /> foundation bracket and into the soil below until a load bearing stratum is encountered. Lateral earth confinement and a driven <br /> external sleeve with a starter pier provide additional stiffness to resist eccentric loading from the foundation.Once all piers are <br /> installed,they are simultaneously loaded with individual hydraulic jacks and closely monitored as pressure is applied to achieve <br /> desired stabilization and/or lift prior to locking off the pier cap. The piers are required to resist vertical loading from the roof <br /> framing,wall framing,floor framing, ,and concrete foundation.Underpinning the structure will remove lateral resistance provided <br /> by soil friction acting on the concrete foundation. Per the following calculation lateral resistance will be provided by soil friction <br /> acting on the unpiered portions of the concrete footing/concrete slab on grade and passive pressure acting on the buried footings <br /> perpendicular to the piered gridlines. <br /> There is no ICC-ES report currently approved for underpinning systems within Seismic Design Category D or higher,thus the <br /> entire underpinning system has been reviewed and analyzed and is therefore a fully engineered system complying with all current <br /> codes and stamped by a licensed design professional.Deep foundation guidelines, load combinations,special inspection and <br /> testing requirements per IBC 2018 have been included.Axial and bending capacities of the external sleeve,analysis of the retrofit <br /> foundation bracket,design reductions,and corrosion considerations have been incorporated in all required calculations per AISC <br /> 360-10.Concrete foundation span capacities have been analyzed per ACI318-14.Bracket fabrication welding has been <br /> performed.conforming to AWS D1.1 performed by CWB qualified welders certified to CSA Standard W47.1 in Division 2. <br /> General <br /> Building Department City of Everett <br /> Building Code Conformance(Meets Or Exceeds Requirements) <br /> 2018 International Building Code(IBC) <br /> 2018 International Residential Code(IRC) <br /> 2018 Washington Building Code <br /> 2018 Washington Residential Code <br /> Dead Loads <br /> Roof Dead Load 15.0 psf <br /> Floor Dead Load 15.0 psf <br /> Brick Veneer over Wood Dead Load 50.0 psf <br /> Interior Wall Dead Load 9.0 psf <br /> Concrete 150.0 pcf <br /> Live Loads <br /> � Roof Snow Load � 25.0 psf <br /> Floor Live Load(Residential) 40.0 psf <br /> 2� 1 � <br />