CESMD

Information for Strong-Motion Station

Leggett - Big Dann Bridge

CGS - CSMIP Station 79761

Earthquakes recorded by this station

 

(Station Photograph - click to enlarge)	(Sensor Layout - click to see PDF File)

   

Latitude	39.8471 N
Longitude	123.6967 W
Elevation (m)	275
Site Geology
Vs30 (m/sec)
Site Class

 

No. of Spans	7
Plan Shape	Straight.
Total Length	583' (177.7m). Bridge spans range from 39.5' (12.0m) to 51.5' (15.7m) long, with one 320' (97.5m) main span.
Width of Deck	28' (8.5m)
Construction Date	1933
Instrumentation	1998. 9 accelerometers on the bridge. 3 accelerometers at a free-field site.

 

Superstructure Type	Concrete T-girders simply supported on concrete piers. One end of each girder has an expansion joint.
Substructure Type	Center span: concrete columns supported by concrete arch. Other spans: concrete columns. 2 columns per bent.
Foundation Type	Spread footings.
Remarks	This bridge was instrumented under the interagency agreement between Caltrans and DOC. A seismic safety gate is installed at the bridge.