Earthworks - Geotechnical Investigation and Design Tables - page 149

Table 12.18 Suitability of compaction plant (Hoerner, 1990).

Compaction plant Principal soil type

Cohesive Granular Rock

Wet Others Well graded Uniform Soft Hard

Coarse Fine Coarse Fine

√√ √√ √√ √√

Smooth wheeled roller

√√ √√ √√ √√

Pneumatic tyred roller OOO

√√ √√ √√

Tamping roller O O O

√√ √√ √√ √√ √√

Grid roller O O

√√ √√ √√ √√ √√ √√

Vibrating roller O O

√√ √√ √√ √√ √√

Vibrating plate O O

√√ √√ √√ √√ √√ √√

Vibro - tamper O

√√ √√ √√

Power rammer O OO

√√ √√ √√ √√ √√

Dropping weight

√√ √√ √√ √√ √√

Dynamic consolidation O

√√ Most suited.
O Can be used but les efficiently.

12.19 Typical lift thickness
•

The lift thickness is dependent on the type of material and the plant.

•

In limited operating room (eg backfill of trenches) small plant are required and
the thickness must be reduced from to achieve the appropriate compaction level.

•

Adjacent to area sensitive to load and/or vibration (eg over services, adjacent to
buildings), then medium sized compaction equipment applies. The thickness levels
would be smaller than in an open area, but not as small as in the light equipment
application.

Table 12.19 Typical lift thickness.

Equipment weight Material type Typical lift thickness Comments

Heavy 10 tonnes Rock fill 750-2000 mm Applies to open areas

≥

Sand & Gravel 500-1200 mm

Silt 300-700 mm

Clay 200-400 mm

Medium Rock fill 400-1000 mm Some controls required, eg

(1.5 to 10 tonnes) Sand & Gravel 300-600 mm Buildings are nearby •

Silt 200-400 mm Over service trenches

•

Clay 100-300 mm Adjacent to walls

•

Small Rock fill 200-500 mm In limited areas, eg

( 1.5 tonnes) Sand & Gravel 150-400 mm In trenches < •

Silt 150-300 mm

•

Around Instrumentation

Clay 100-250 mm Adjacent to walls •