SDC’s and Detailing Requirements Locations with Different Soils

1000 year return periodDerrell Manceaux, FHWA

Zone 1-SDC “A”Zone 2-SDC “B”Zone 3-SDC “C”Zone 4-SDC “D”

Seismic Design Category (zone)(500 year Return Period)

SITE CLASS “B”

Zone 1-SDC “A”Zone 2-SDC “B”Zone 3-SDC “C”Zone 4-SDC “D”

Seismic Design Category (zone)(1000 Year Return Period)

Zone 1-SDC “A”Zone 2-SDC “B”Zone 3-SDC “C”Zone 4-SDC “D”

SITE CLASS “C”

Seismic Design Category (zone)(1000 Year Return Period)

Zone 1-SDC “A”Zone 2-SDC “B”Zone 3-SDC “C”Zone 4-SDC “D”

SITE CLASS “D”

Seismic Design Category (zone)(1000 Year Return Period)

Zone 1-SDC “A”Zone 2-SDC “B”Zone 3-SDC “C”Zone 4-SDC “D”

SITE CLASS “E”

Seismic Design Category (zone)(1000 Year Return Period)

LRFD Seismic Details Required(Zone 1- SD1 > 0.10 g)

Site Class B

Soil “B” rock

LRFD Seismic Details Required(Zone 1SD1 > 0.10 g)

Site Class C

Soil “C” N>50 (stiff soil)

LRFD Seismic Details Required(Zone 1 SD1 > 0.10 g)

Site Class D

Soil “D”15<N<50 (soft soil)

Site Class E

Soil “E” N<15 (poor soil)

LRFD Seismic Details RequiredZone 1 SD1 ( > 0.10 g)