San Quentin Prison Seawall retaining wall
San Quentin Prison Seawall concrete coring
San Quentin Prison Seawall concrete facade

San Quentin Prison sits on Point San Quentin bounded by the San Francisco Bay. The site is laterally supported on the bay boundaries by the precast concrete seawall that was constructed in 2002. SGH investigated cracking and spalling of the over 1200 ft long seawall and also provided litigation support.

Scope | Solutions

The structure consists of prestressed concrete panels grouted into H-shaped pilaster. The pilaster foundations sit in bay soils and at low tide the wall and surrounding beach are exposed, but at high tide, the lower portion of the wall and the beach are submerged.

SGH conducted a condition assessment of the precast concrete seawall and opined on the causes of cracking and spalling. For this project, we:

  • Performed a visual survey of the site and tidal conditions
  • Performed in-house petrographic analyses of grout and concrete
  • Reviewed the design and conducted an independent structural analysis
  • SGH provided a written report summarizing the causes of cracking and spalling, provided expert testimony at mediation, and contributed to a successful settlement.