Table 2-3 – Modulus of Soil Reaction, E’

PIPE EMBEDMENT MATERIAL

Average E' psi (kPa)
For Degree of Embedment Compaction

ASTM D2321⁽¹⁾

ASTM D2487

AASHTO M43 Notation

Min. Std. Proctor Density (%)

Lift Placement Depth

Slightly < 85%

Moderate 85%-95%

High
> 95%

IA

Open-graded, clean manufactured aggregates

N/A

Angular crushed stone or rock, crushed gravel, crushed slag; large voids with little or no fines

5
56

Dumped

18"
(0.5m)

1000
(6,900)

3000
(20,700)

3000
(20,700)

3000
(20,700)

IB

Dense-graded, clean manufactured, processed aggregates

N/A

Angular crushed stone or other Class IA material and stone/sand mixtures; little or no fines

II

Clean, coarse-grained soils

GW

Well-graded gravel, gravel/sand mixtures; little or no fines

57
6
67

85%

12"
(0.3m)

N/R

1000
(6,900)

2000
(13,800)

3000
(20,700)

GP

Poorly-graded gravels, gravel/sand mixtures; little or no fines

SW

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

SP

Poorly-graded sands, gravelly sands; little or no fines

III

Coarse-grained soils with fines

GM

Silty gravels, gravel/sand/silt mixtures

Gravel and sand with <10% fines

90%

9"
(0.2m)

N/R

N/R

1000
(6,900)

2000
(13,800)

GC

Clayey gravels, gravel/sand/clay mixtures

SM

Silty sands, sand/silt mixtures

SC

Clayey sands, sand/clay mixtures

IVA⁽²⁾

Inorganic fine-grained soils

ML

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

.

.

.

N/R

N/R

N/R

N/R

CL

Inorganic clays of low to medium plasticity; gravelly, sandy, or silty clays; lean clays

IVB

Inorganic fine-grained soils

MH

Inorganic silts, micaceous or diatomaceous fine sandy or silty soils, elastic silts

.

.

.

N/R

N/R

N/R

N/R

CH

Inorganic clays of high plasticity, fat clays

V

Organic or highly organic soils

OL

Organic silts and organic silty clays of low plasticity

.

.

.

N/R

N/R

N/R

N/R

OH

Organic clays of medium to high plasticity, organic silts

PT

Peat and other high organic soils