Laserfiche WebLink
EN <br /> SFA Design Group, ccc <br /> STRUCTURAL I GEOTECHNICAL I SPECIAL INSPECTIONS PROJECT NO. SHEET NO. <br /> M F R20-014 <br /> PROJECT DATE <br /> Orme Residence Underpinning 3/2/2020 <br /> SUBJECT BY <br /> Push Pier Design Requirements MEK <br /> I Structural Narrative <br /> The structural calculations and drawings enclosed are in reference to the design of the foundation underpinning of the 2-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, concrete slab on grade, and concrete foundation. Underpinning the structure will remove <br /> lateral resistance provided by soil friction acting on the concrete foundation. Per the following calculation lateral resistance will be <br /> provided by soil friction acting on the unpiered portions of the concrete footing/concrete slab on grade and passive pressure acting <br /> on the buried footings 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 2015 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 /> 360-16. Concrete foundation span capacities have been analyzed per ACI318-14. Bracket fabrication welding has been performed <br /> by Behlen Mfg Co. conforming to AWS D1.1 performed by CWB qualified welders certified to CSA Standard W47.1 in Division 2. <br /> In addition, Behlen Mfg Co. has received US99/1690 certification meeting ISO 9001:2008 requirements by ANAB accredited SGS. <br /> 'General <br /> Building Department City of Everett <br /> Building Code Conformance(Meets Or Exceeds Requirements) <br /> 2015 International Building Code(IBC) <br /> 2015 International Residential Code(IRC) <br /> Dead Loads <br /> Roof Dead Load 15.0 psf <br /> Floor Dead Load 15.0 psf <br /> Wood Wall Dead Load 12.0 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 />