Unified Soils 

 Classification 



ASTM 

 Mesh 



mm 

 Size 



Phi 

 Value 



Wentworth 

 Classification 



COBBLE 



mm-tm. 



COARSE 

 GRAVEL 



FINE GRAVEL 



^^^^^^Ff 



s 



A 

 H 

 D 



A 



^.^y^'Mf^'i.'^a-y-izs^ 



coorse 



medium 



fine 



SILT 



CLAY 



<> f rr .:fji if f»r" 



256.0 -9.0 







4.0 -2.0 



y77P7. 



liO 



..IIWMJW*"'".' 



^ 



2.0; J- 1.0 



e;-hI25 



0.5 



r^ 



■ILLUV'WWV" 



^^60 



r TT"^ r r 7 



v////('v<y. 



^,40,^,0.42^^,l.25^ 



0.25 2.0 



120 0,125 3.0 



; ^^^<^;200?^6.074'^;^:%-3:75l 



l"W.».^*WWff.^W 



230 0.062 4.0 



'V//////''y-}.-vy///. o ni 



:^M^:;y;v<>^ 0,0039 8.0 



;0.OO24 12.0 



O 









^'7l Mv ■ .^■,^ l . ■ . ^ r '^ ^^ ■ - ■ ^ T -UMJ■ ^ ■ ' . T .M- ^ M ■^' . ^ . ^' .; : , T ■ ■ ^ ^ / ■TT■''v\ 



:> 



=:> 



BOULDER 



COBBLE 



PEBBLE 



GRAVEL 



very 

 coarse 



coarse 



medium 



fine 



very fine 



A 

 N 

 



SILT 



CLAY 



COLLOID 



Figure 4-7. Grain-size scales (soil classification). 



4-13 



