Located in Redwood City, Arroyo Green provides 117 units of housing for seniors making up to 50% of the area’s median income.
Site Square Footage: 139,400 sq. ft.
Date Completed: 2021
Construction Cost: $76.6 million
Client: MidPen Housing
Architect: DAHLIN Group Architecture/Planning
Structural Engineer: Peoples Associates Structural Engineers
Civil Engineer: BKF Engineers
General Contractor: Devcon Contractors
Rockridge Geotechnical (RG) performed the geotechnical investigation, consulted during design, and provided geotechnical services during construction.
Rockridge Geotechnical judged the primary geotechnical issues affecting the development were: 1) the potential for liquefaction-induced settlement and reduction in bearing capacity beneath the proposed building, 2) layers of weak, compressible clay underlying the site that will initiate a new cycle of consolidation if subjected to new loads, 3) the presence of highly expansive near-surface soil, and 4) providing suitable vertical and lateral support for the new building.
To mitigate these concerns, Rockridge Geotechnical recommended a layer of non-expansive fill below the slab-on-grade floor and ground improvement with drilled displacement columns. The ground improvement system was designed to reduce the liquefaction potential and transfer building loads to stronger, less compressible soils.
The complex won the 2018 Gold Nugget Merit Award for Best Senior Housing Community and the 2018 SAGE Award for Best Affordable Rental Community, and it was a finalist for the 2019 NAHB 55+ Housing Award.