The San Francisco Mint

Project: Rockfall protection and shotcrete retaining wall with rock bolts

Client: U.S. Department of Treasury

Location: San Francisco, CA

Design Engineer:
Stevens, Ferrone and Bailey

Geotechnical Engineer:
Ninyo & Moore

Contractor:
Soil Engineering Construction, Inc.

Project Description:

The San Francisco Mint is located on the top of a hill with steep serpentine slopes dropping off on three sides. Considerable weathering has caused the rock slopes to unravel to the point where the property was threatened. Soil Engineering removed more than 1000 cubic yards of serpentine soil, installed over 200 rock bolts, applied over 1,200 cubic yards of shotcrete, and installed several thousand square feet of rockfall protection mesh.

The majority of the rock anchors were installed using a lightweight rock drill and down-hole hammer fixed to the boom of a long-front excavator utilizing a custom-made attachment.

Stringent security procedures and the need to accommodate frequent deliveries to The Mint and Mint workforce shift changes required careful coordination of all construction activities with Mint personnel.

• Rock Percussion Drilling

• Rock Anchors

• Tecco Mesh™

• Shotcrete Slope Protection

• Excavation of Serpentine Soils

• Certified Rock Climbing Specialists

• Coordinate with Federal Police in High-Security Environment