Gpec8

Synopsis

gpec8 [OPTIONS] [FILE]

Description

Determines the EC8 category of a site for horizontally layered models given through stdin or FILE.

The input is the soil column (in a format similar to Gpdc, Gpell, Gpspac or Gpsh. The output is the EC8 site category depending mainly on the value of the time-averaged velocity over the top 30 m ("VS30"), and also on the thickness of the softest layers (categories E and S1)

EC8 site categories

• Category A : Rock, 800 m/s < VS30 and "including at most 5 m of weaker material at the surface". The latter condition is interpreted here as : VS05 > 360 m/s, where VS05 is the average velocity over the top 5 m.

• Category B : Stiff soil / soft rock, 360 m/s < VS30 < 800 m/s

• Category C : Normal soil 180 m/s < VS30 < 360 m/s

• Category D : Soft soil, 100 m/s < VS30 < 180 m/s >

• Category E : Thin soft soil with 100 m/s < VS < 360 m/s and a thickness between 5 and 20 m , overlying a much stiffer unit with VS > 800 m/s

• Category S1 : Special category 1 : very soft soil (VS30 < 100 m/s), or containing at least 10 m of soft clays/silts with high plasticity index (interpretation considered here : VS lower than 100 m/s over a thickness larger than 10 m, labeled as "S1?")

• Category S2 : Special category 2 : liquefiable soils, or all those not covered by A-E and S1 category: !! Cannot be identified from the sole VS velocity profile!!

Format for layered models

 Line 1  : <number of layers n including half-space for first model>
 Line 2  : <thickness (m)> <Vp (m/s)> <Vs (m/s)> <Density (kg/m3)>[ <Qp> <Qs>]
 ....
 Line n+1 : 0 <Vp (m/s)> <Vs (m/s)> <Density (kg/m3)>[ <Qp> <Qs>]
 Line n+2 : <number of layers m including half-space for a second model - if wished>
 Line n+3 : <thickness (m)> <Vp (m/s)> <Vs (m/s)> <Density (kg/m3)>[ <Qp> <Qs>]
 ....
 Line n+m+2 : 0 <Vp (m/s)> <Vs (m/s)> <Density (kg/m3)>[ <Qp> <Qs>]
 Line n+m+3 : <number of layers l including half-space for a third model - if wished>
 ....

Quality factors are not mandatory. Any number of models can be given as input.

Examples

gpec8 Gpec8.model

Determines the EC8 site category for the soil columns in "ec8.model"

• Output

Vs30 964.286 Class A
Vs30 816.992 Class A
Vs30 444.444 Class B
Vs30 695.364 Class B
Vs30 271.084 Class C
Vs30 136.082 Class D
Vs30 330.275 Class E
Vs30 80 Class S1
Vs30 135.135 Class S1?