Information for Strong-Motion Station
Oakland - Caldecott Tunnel Bore 4
CGS - CSMIP Station 58540
Earthquakes recorded by this station
(Station Photograph - click to enlarge)(Sensor Layout - click to see PDF File)
Latitude 37.8582 N
Longitude 122.2146 W
Elevation (m) --
Site Geology  
Vs30 (m/sec)  
Site Class  
No. of Spansn/a
Plan Shapecurved (end portions) and straight (middle portion); Slope: 4.769%
Total Length1,036 meters (3,400 feet)
Width of Deckn/a
Construction Date2010 - 2013
Instrumentation2013. 15 accelerometers at 5 locations inside the tunnel and 6 accelerometers at 2 ground surface sites near end portals of the tunnel.
Superstructure TypeBore 4 is 41.25 feet wide and has two 12-ft lanes for west-bound traffic on Highway 24, a 10-ft north shoulder, a 2-ft north emergency walkway, a 2-ft south shoulder, and a 3-ft south emergency walkway. Bore 4 is connected to Bore 3 by 7 cross-passages which serve as emergency exits.
Substructure TypeThe horseshoe-shaped tunnel is 50 feet wide and 32 feet high.
Foundation TypeBore 4 uses a double lining system consisting of an initial support system and a cast-in-place reinforced concrete final lining. A waterproof membrane was installed between the initial support and the final lining.
RemarksBore 4 of Caldecott Tunnel opened to traffic on November 16, 2013. It was instrumented during construction under the interagency agreement between Caltrans and DOC. Bore 3 of Caldecott Tunnel (south of Bore 4; built in early 1960s) was instrumented in 1979 (CSMIP Sta. 58359).