Soil Properties-continue

0.135γ d + 64.7

κ dry =

20%.

(9.2)

2700 - 0.947γ d

The thermal conductivity is related to the specific heat such that κ = kth⋅C where kth is the

thermal diffusivity (m2/s) and C is the specific heat (J/kg⋅K).

Finally, it should be noted that often, the saturated hydraulic conductivity, Ksat (cm/s), is

called the saturated permeability, kpsat (cm2). The two are related by

kpsat g ( Nd 2 ) g

K sat =

=

(9.3)

ν

η ρf

where N is a pore shape dependent proportionality factor, d (m) is the soil grain diameter,

g (m/s2) is the acceleration due to gravity, ν (m2/s) is the kinematic fluid viscosity, η

(kg/m⋅s) is the dynamic fluid viscosity, and ρf is the fluid density (kg/m3).

FASST provides default values for all of the above parameters, for 15 of the USCS soil

types (see Tables 9.2.1 and 9.2.2). Parameters not found in the tables are calculated based

on the preceding discussion. The USCS soil types that FASST allows are

GW

Well-graded gravels, gravelsand mixtures, little or no fines

GP

Poorly graded gravels, gravelsand mixtures, little or no fines

GM

Silty gravels, gravelsandsilt mixtures

GC

Clayey gravels, gravelsandclay mixtures

SW

Well-graded sands, gravelly sands, little or no fines

SP

Poorly graded sands, gravelly sands, little or no fines

SM

Silty sands, sandsilt mixtures

SC

Clayey sands, sandclay mixtures

ML

Inorganic silts and very fine sands, rock flour, silty or clayey fine

sands or clayey silts with slight plasticity

CL

Inorganic clays of low to medium plasticity, gravelly clays, sandy

clays, silty clays, lean clays

OL

Organic silts and organic silty clays of low plasticity

CH

Inorganic silts, micaceous or diatomaceous fine sandy or silty

soils, elastic silts

MH

Inorganic clays of high plasticity, fat clays

OH

Organic clays of medium to high plasticity, organic silts

Pt

Peat and other highly organic soils

SMSC

Mixed SM and SC soils

CLML

Mixed CL and ML soils

EV

Evaporites (salt pans, similar properties to SW)

CO

Concrete

AS

Asphalt

RO

Bed rock (assumed to be granitic)

SN

Permanent snow field or glacier

UK

Unknown (This is defaulted to SM.)

US

User-supplied variables

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