Information for Strong-Motion Station
Concord - 9-story Office Bldg
CGS - CSMIP Station 58638
Earthquakes recorded by this station
(Station Photograph - click to enlarge)(Sensor Layout - click to see PDF File)
Latitude 37.9738 N
Longitude 122.0373 W
Elevation (m) 12
Site Geology Shallow alluvium over rock (sandstone)
Vs30 (m/sec) 322 (inferred)
Site Class D
Remarks/Notes Site information sources
No. of Stories above/below ground9/6
Plan ShapeRectangular
Base Dimensions250' x 125'
Typical Floor DimensionsSame as base dimensions
Design Date210' x 100'
Instrumentation1992. 14 accelerometers, on 4 levels in the building. 3 accelerometers at a reference free-field site.
Vertical Load Carrying SystemFor levels above grade, steel beams and columns support 3" metal deck floors topped with 3.25" light-weight concrete. The beams are designed as composite sections. Below grade, the floor system consists of 5" concrete waffle slab and 15" deep concrete joists supported by steel columns encased in concrete.
Lateral Force Resisting SystemAbove Grade: Eccentrically braced steel frames (EBFs) in the core of the building with back-up perimeter moment resisting steel frames. Below Grade: Concrete walls along the perimeter and in the core of the building.
Foundation TypeThe foundation consists of 4' deep concrete mat under the central core which supports the eccentrically braced frames and 2' - 3' deep concrete spread footings under the retaining walls and columns.
RemarksThe seismic design of the building was based on the 1982 Uniform Building Code. The building provides 6 levels of underground parking space for 9 levels of office space plus a penthouse above grade.