Graded Soils / And What ???

  I decided to take a minute to gather my thoughts and read some of your coments as to get a feel for what you need and how I might better assist in these matters of construction. The field is huge, it's hard to say. So leave a clue, that I might work with.

  Help Me to Help You!!!!

  And I purpose to stop jumping around so much, you know it's easy to get off the subject, and on to a subject utterly unrelated, you just can't help it. And I'm not trying to make excuses it's just a fact, when your full and running over with ??( WELL FORGET IT ) you loose control.

  Ok I want to close on soil, but I can't just yet!

  When the soil sample is taken, it will consist of a mixture of every type and composition of the soil ie, it will be composed of gravel, sand, silt, and clay. And it is described by the most predominate part, ie. Is it predominately gravel, sand, silt, or clay. So it's description references the mixture with the most  prevalent part; by saying the soil is a gravelly sand, it means, sand mixed with gravel, or a silty sand would be a sand mixed with silt or clayey sand, that is sand mixed with clay.

These classification of soils are critical for engineers to be able to identify problem soils.

Classifications of soils developed by the American Society for Testing and Materials (ASTM) standards are D 2487 and D 2488. And the Unified Soil Classification System ( USCS ) are used to describe the grain size of a soil.

ASTM Terminology

• Coarse-Grained Soils     More than 50% retained on a 0.075 mm(#200) sieve.
• Fine-Grained Soils            50% or more passes a 0.075 mm (#200) sieve.
• Gravel                                        Material passing a 75 mm (3 inch) sieve and retained on a 4.75 mm (#4) sieve.
• Coarse Gravel                      Material passing a 75 mm (3 inch) sieve and retained on a 19.0 mm (3/4 inch) sieve.
• Fine Gravel                             Material passing a 19.0 mm (3/4 inch) sieve and retained on a 4.75 mm (#4) sieve.
• Sand                                             Material passing a 4.75 mm sieve (#4) and retained on a 0.075 mm (#200) sieve.
• Coarse Sand                           Material passing a 4.75 mm sieve (#4) and retained on a 2.00 mm (#10) sieve.
• Medium Sand                       Material passing a 2.00 mm sieve (#10) and retained on a 0.475 mm (#40) sieve.
• Fine Sand                                Material passing a 0.475 mm (#40) sieve and retained on a 0.075 mm (#200) sieve.
• Clay                                            Material passing a 0.075 mm (#200) sieve that exhibits plasticity, and strength when dry.
• Silt                                               Material passing a 0.075 mm (#200) sieve that is non-plastic, and has little strength when dry.
• Peat                                            Soil of vegetable matter.

Letter Definition:

(G) Gravel, (S) Sand, (M) Silt, (C) Clay, (O) Organic

(P) Poorly graded-uniform particle sizes. (W)Well graded diversified particle sizes. (H) High plasticity. (L) Low plasticity.

This is the soils classification systems most used in construction, engineering, and geology. It broadly breaks down soils to these two classifications (1) Granular: ( Coarse- grained soils more than 50% of coarse fractions retained on a #200 sieve. ) 

This granular group symbols are "GW": Well-graded gravels and gravel-sand mixtures, with 5% fines or no fines, and are gravels that, 50% or more of course fractions are retained on a #4 sieve, called Clean gravels. "GP": Poorly-graded gravels and gravel-sand mixtures with 5% fines or no fines. Then there are Gravel with 5 to 15% fines, and this group GM; Silty gravels, gravel-sand-silt mixtures. And "GC";Clayey gravels, gravel-sand-clay mixtures. "GW-GM"; Well-graded gravel with silt. "GW-GC"; Well-graded gravel with clay. "GP-GM"; Poorly-graded gravel with silt. "GP-GC"; Poorly-graded gravel with clay.

Fines are defined by the American Association of State Highway and Transportation Officials ( AASHTO M 147 ) as natural or crushed sand passing the #10 sieve and mineral particles passing the #200 sieve.  

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Thanks in advance.