Information for Strong-Motion Station
San Francisco; US Court of Appeals; Bldg Array 1
NSMP Station 1735
Earthquakes recorded by this station
(Station Photograph - click to enlarge)(Sensor Layout - click to see PDF File)
Latitude 37.7804 N
Longitude 122.4099 W
Elevation (m) 11
Site Geology  
Vs30 (m/sec)  
Site Class  
No. of Stories above/below ground4/1
Plan Shaperectangular with a large central atrium
Base Dimensions330 ftx265 ft
Typical Floor Dimensions330 ftx265 ft with a large central atrium
Design Date1905 (extended in 1933)
Instrumentation1994, 36 accelerometers on six levels of building.
Vertical Load Carrying System6-inch thich Concrete slab supported by steel frames and bearing masonry walls.
Lateral Force Resisting SystemOriginally steel frame with unreinforced masonry and stone walls. The lateral system was retrofitted by using 256 friction pendulum base isolators, adding recinforced concrete shear walls, strenthening the diaphragms, and adding a new steel moment resisting frame for atrium.
Foundation TypeSteel grillage footings encased in unreinforced concrete. The foundation system for the 1933 wing consists of reinforced-concrete piles and pile caps.