San Francisco New General Hospital

• Client: San Francisco Department of Public Works
• Location: San Francisco, California
• Project Manager: Haze Rodgers
• Principal-in-Charge: Ramin Golesorkhi
• Architect: FCA Architects
• Structural Engineer: Arup
• Moat Wall/Shoring Engineer: SOHA Engineers
  

As part of the San Francisco General Hospital (SFGH) Rebuild Project, Treadwell & Rollo is currently providing geotechnical services to the San Francisco Department of Public Works and SFGH during construction of the permanent moat wall for the new Building 25, general site improvements, and utility relocation. Building 25 will be a nine story (two below grade levels) 284-bed acute care hospital with a basement plan area of approximately 80,000 square feet.

To reduce seismically-induced forces, the building will incorporate a base isolation system at the foundation level which will allow it to move freely up to 30 inches in horizontal direction. To accommodate the movements, a void space (commonly referred to as a moat) will be constructed between the structure's basement wall and the adjacent permanent perimeter wall (moat wall). The moat wall will be approximately 1,470 feet long and 25 to 45 feet in height. It will be constructed using soil cement mixed columns, steel soldier beams, and approximately 1,160 permanent tiebacks. The isolators will be founded on a concrete mat. To resist against uplift and overturning loads, the mat will be tied down using approximately 280 permanent anchors.