Compaction Equipment : Rollers
posted in Soil Engineering |
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A wide variety of equipment is used to obtain compaction in the field. Sheepsfoot rollers generally are used on soils that contain high percentages of clay. Vibrating rollers are used on more granular soils.
To determine maximum depth of lift, make a test fill. In the process, the most suitable equipment and pressure to be applied, lb/in2 (kPa), for ground contact also can be determined. Equipment selected should be able to produce desired compaction with four to eight passes. Desirable speed of rolling also can be determined.
Average speeds, mi/h (km/h), under normal conditions are given in Table below
| Type |
mi/h | km/h |
| Grid rollers | 12 | 19.3 |
| Sheepsfoot rollers | 3 | 4.8 |
| Tamping rollers |
10 | 16.1 |
| Pneumatic rollers | 8 | 12.8 |
Compaction production can be computed from
yd3/h (m3/h) = 16WSLFE / P
where
W = width of roller, ft (m)
S = roller speed, mi / h (km / h)
L = lift thickness, in (mm)
F = ratio of pay yd3 ( m3) to loose yd3 ( m3)
E = efficiency factor ( allows for time losses, such as those due to turns); 0.90, excellent; 0.80, average; 0.75, poor
P = number of passes
