Structural PE Stamp in Seattle, WA — Seismic Design Category D Review

My Seattle seismic review starts with parameters: mapped spectral accelerations, site class from the geotechnical report, and the resulting design spectral values and Seismic Design Category. Then the system — I verify the lateral resisting system's selection suits the building height, occupancy, and any irregularities, and that the analysis method fits the structure. Detailing is where Category D lives or dies: I check special detailing provisions element by element — confinement in concrete, connection ductility in steel, hold-downs and shear transfer in wood — against what is actually drawn, not what a typical detail library shows. Diaphragms, collectors, and drag struts get their own verification, since the seismic force path through the floor system is a classic weak point. Nonstructural anchorage — equipment, cladding, ceilings — is checked for the component seismic demands. The sealed package reads as one seismic argument from parameters to details.

Beyond the seismic detailing, I trace the complete lateral load path: how forces enter at the cladding and roof, travel through diaphragms and collectors, down the vertical elements, and into foundations designed for the site's soils. Irregularities — soft stories, torsional eccentricity, vertical discontinuities — get the additional analysis the code requires for Category D, and I verify the drawings reflect any resulting design consequences rather than just the analysis report. The geotechnical linkage closes the loop: foundation type and depth per the report, liquefaction mitigation where required, and site class consistency between the soils report and the seismic parameters. Wind and snow are verified per code as supporting loads. SDCI's structural reviewers audit exactly this chain — my review makes sure it holds before they see it.

I verify these against project documents before the Washington seal goes on a Seattle structural set. • Washington PE or SE credential verified; matches the structure's licensing requirements • Seismic parameters and site class from project-specific geotechnical report • Seismic Design Category confirmed; system selection appropriate • Category D ductile detailing verified element by element as drawn • Diaphragms, collectors, and drag struts designed for seismic forces • Irregularities identified; required analysis and detailing consequences shown • Liquefaction and soft-soil provisions addressed per the geotechnical report • Seattle Services Portal submittal organized; calculations mirror the drawings