HWA provided geotechnical engineering design support for the replacement of parallel bridges. HWA's work determined that reductions in seismic waves associated with soft lake sediments were large enough that utilizing site-specific seismic parameters negated the need for implementing slope stabilization methods. This saved the City 18M in construction costs and this project was the winner of the 2022 APWA National Gold Award.

HWA provided geotechnical support for design and construction of a proposed bridge and stream restoration in Burien, WA. HWA performed field explorations, review of existing information, borings, subsurface soil, groundwater conditions, detailed reconnaissance of steep slope conditions, pavement restoration, earthwork recommendations, seismic performance, load carrying capacity, bridge foundation capacity, and lab testing. HWA was retained to provide geotechnical services during construction.

HWA served as geotechnical engineering for the replacement of the twin parallel bridges crossing the Sammamish River, evaluations were broken into several phases including a scour repair evaluation, bridge rehabilitation evaluation, and final design of a new bridge structure if rehabilitation was not feasible. HWA developed a solution to reduce load increments due to grade changes by recommending over excavation and replacement with Geofoam to offset the anticipated load increments.