Table 9 











Sediment Particle Sizes 











Unified Soils Classification 



ASTM Mesh No. 



Size in mm 



PHI Size 



Wentworth Classification 







4096.00 



-12.0 











1024.00 



-10.0 



Boulder 









256.00 

 128.00 



-8 





G 



Cobble 





-7.0 











107.64 



-6.75 



Cobble 









90.51 



-6.5 











76.00 



-6.25 





R 







64.00 

 58.82 



-6.0 

 -5.75 



















45.26 



-5.5 







Coarse Gravel 





38.00 

 32.00 

 26.91 

 22.63 



-5.25 

 -5.0 

 -4.75 

 -4.5 





A 







19.00 



-4.25 



Pebble 



V 







16.00 



-4.0 











13.45 



-3.75 











11.31 



-3.5 







Fine Gravel 





9.51 



-3.25 





E 





2.5 



8.00 



-3.0 









3 



6.73 



-2.75 









3.5 



5.66 



-2.5 









4 



4.76 



-2.25 





L 





5 

 6 



4.00 

 3.36 



-2.0 

 -1.75 













Coarse Sand 



7 



2.85 



-1.5 



Granule 







8 



2.35 



-1.25 









10 



2.00 



-1 









12 



1.68 



-0.75 









14 



1.41 



-0.5 



Very Coarse 







16 



1.19 



-0.25 





S 



Medium Sand 



18 

 20 



1.00 

 0.84 



0.0 







0.25 









25 



0.71 



0.5 



Coarse 







30 



0.59 



0.75 





A 





35 

 40 



0.50 

 0.42 



1.0 

 1.25 















45 



0.35 



1.5 



Medium 







50 



0.30 



1.75 





N 





60 

 70 



0.25 

 0.210 



2.0 

 2.25 













Fine Sand 



80 



0.177 



2.5 



Fine 







100 



0.149 



2.75 





D 





120 

 140 



0.125 

 0.105 



3.0 

 3.25 















170 



0.088 



3.5 



Very Fine 







200 



0.074 



3.75 









230 

 270 



0.0625 

 0.053 



4.0 

 4.25 















325 



0.044 



4.5 





M 



Silt 



400 



0.037 



4.75 











0.031 



5.0 



Silt 









0.0156 



6.0 











0.0078 



7.0 





U 







0.0039 

 0.0020 



8.0 

 9.0 















Clay 





0.00098 



10.0 



Clay 









0.00049 



11.0 





D 







0.00024 

 0.00012 



12.0 











13.0 



Colloid 









0.00006 



14.0 







Chapter 4 Laboratory Techniques and Approaches 



67 



