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[� 5FA Design Group, LLC '^ <br />®� STRUCTURAL I GEOTECHNICAI_ I SPECIAL INSPECTIONS PROJECT NO. SHEET NO. <br />PROJECT DATE <br />Gale Residence Underpinning 12/24/2023 <br />SUBJECT IBY <br />Push Pier Design Requirements <br />CAF <br />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 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 AC1318-14. 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 />2018 International Building Code (IBC) <br />2018 International Residential Code (IRC) <br />2018 Washington State Building Code <br />2018 Washington State Residential Code <br />Dead Loads <br />Roof Dead Load <br />15.0 psf <br />Floor Dead Load <br />15.0 psf <br />Wood Wall Dead Load <br />12.0 psf <br />Interior Wall Dead Load <br />9.0 psf <br />Deck Dead Load <br />12.0 psf <br />Concrete <br />150.0 pcf <br />Live Loads <br />Roof Snow Load 25.0 psf <br />Deck Live Load 60.0 psf <br />Floor Live Load (Residential) 40.0 psf <br />Soil Parameters <br />Reference Standards Conform to IBC Chapter 11. 8 <br />"Soils & Foundations". <br />Allowable Foundation Pressure (Assumed) 1500 psf <br />