Page 92 - Buried Pipe Design

TABLE 3.1 Description of Embedment Material Classifications
Soil class Soil Description of material classification
1
1
Class I soils ∗ — Manufactured angular, granular material, to 1 in
4
2
(6 to 40 mm) in size, including materials having regional
significance such as crushed stone or rock, broken
coral, crushed slag, cinders, or crushed shells.
Class II soils † GW Well-graded gravels and gravel-sand mixtures, little or
no fines. 50 percent or more retained on no. 4 sieve.
More than 95 percent retained on no. 200 sieve. Clean.
GP Poorly graded gravels and gravel-sand mixtures, little or
no fines. 50 percent or more retained on no. 4 sieve.
More than 95 percent retained on no. 200 sieve. Clean.
SW Well-graded sands and gravelly sands, little or no fines.
More than 50 percent passes no. 4 sieve. More than
95 percent retained on no. 200 sieve. Clean.
SP Poorly graded sands and gravelly sands, little or no
fines. More than 50 percent passes no. 4 sieve. More
than 95 percent retained on no. 200 sieve. Clean.
Class III soils ‡ GM Silty gravels, gravel-sand-silt mixtures. 50 percent or
more retained on no. 4 sieve. More than 50 percent
retained on no. 200 sieve.
GC Clayey gravels, gravel-sand-clay mixtures. 50 percent or
more retained on no. 4 sieve. More than 50 percent
retained on no. 200 sieve.
SM Silty sands, sand-silt mixtures. More than 50 percent
passes no. 4 sieve. More than 50 percent retained on
no. 200 sieve.
SC Clayey sands, sand-clay mixtures. More than 50 percent
passes no. 4 sieve. More than 50% retained on no. 200
sieve.
Class IV soils ML Inorganic silts, very fine sands, rock flour, silty or clayey
fine sands. Liquid limit 50 percent or less. 50 percent or
more passes no. 200 sieve.
CL Inorganic clays of low to medium plasticity, gravelly
clays, sandy clays, silty clays, lean clays. Liquid limit
50 percent or less. 50 percent or more passes no. 200
sieve.
MH Inorganic silts, micaceous or diatomaceous fine sands or
silts, elastic silts. Liquid limit greater than 50 percent.
50 percent or more passes no. 200 sieve.
CH Inorganic clays of high plasticity, fat clays. Liquid limit
greater than 50 percent. 50 percent or more passes no.
200 sieve.
Class V soils OL Organic silts and organic silty clays of low plasticity.
Liquid limit 50 percent or less. 50 percent or more
passes no. 200 sieve.
OH Organic clays of medium to high plasticity. Liquid limit
greater than 50 percent. 50 percent or more passes no.
200 sieve.
PT Peat, muck, and other highly organic soils.
∗ Soils defined as Class I materials are not defined in ASTM D 2487.
† In accordance with ASTM D 2487, less than 5 percent pass no. 200 sieve.
‡ In accordance with ASTM D 2487, more than 12 percent pass no. 200 sieve. Soils with 5 to
12 percent pass no. 200 sieve fall in borderline classification, e.g., GP-GC.
SOURCE: Reprinted by permission. Copyright ASTM.

68