Lake Merritt Municipal Boathouse

• Client: murakami/Nelson Architects
• Location: Oakland, CA
• Principal-in-Charge: Lori A. Simpson
• Architect: murakami/Nelson Architect
• Structural: Degenkolb

The Lake Merritt Municipal Boathouse is a LEED Gold (pending), 17,000 square foot, mixed-use, steel and concrete building on the shore of Lake Merritt in downtown Oakland. Treadwell & Rollo, Inc. performed a geotechnical investigation to evaluate subsurface conditions and provide recommendations for the proposed renovation and seismic rehabilitation. The scope of work for the geotechnical investigation included exploring subsurface conditions by drilling borings, performing cone penetration tests (CPTs) and dynamic penetrometer tests (DPTs), and performing laboratory tests and engineering analyses.

Situated on the shore of Lake Merritt, soil conditions unsuitable for foundation support were encountered. Weak compressible marsh deposits and liquefiable soil are present under portions of the site. Therefore, most of the new loads are supported on micropiles, which are small-diameter, drilled, deep foundations. New retaining walls constructed beyond the building for exterior improvements are supported on drilled piers.

We provided geotechnical special inspection services during construction. Our services included observation and testing of micropiles, observation of footing excavations and pier drilling, and consultation as issues during construction arose.

Image courtesy of murakami/Nelson Architectural Corporation.