Fill specifications - Geotechnical Investigation and Design Tables - page 221

•

Other measures may also be used as shown in the Table.

Table 17.15 Earthworks control measures.

Method Measurement Typical value Comment

Relative Insitu density and Trenches : RC 90% This can be an

Compaction (RC) maximum dry density Subgrade RC 95% expensive process

>

Pavements RC

>

98% due to the large

number of tests
required

Method Equipment Lift 250 mm Useful in rocky +

specification thickness No. of 5 No. passes material +

passes

Degree Of Density, Moisture Base DOS 70% Near OMC

<

Saturation (DOS) content and specific Sub - base DOS

<

80%

gravity Subgrade DOS 95% ∼

Modulus Direct eg plate load test Base E 400 MPa Useful in rocky >

Sub - base E

>

200 MPa material

Rocky subgrade
E

>

100 MPa

17.16 Typical compaction requirements
•

The minimum compaction requirements depends on the type of layer, thickness,
operating area, proximity to services/structures and equipment used.

Table 17.16 Typical compaction requirements.
Type of

Element % Standard Placement moisture

construction compaction content

Roads and Heavily loaded pavement Base 100% Dry of OMC, >

rail DOS 70% <

Lightly loaded pavement Subbase 98 % Dry of OMC,

DOS

>

80%

<

Subgrade WPI

<

2200

>

95% OMC

General embankment fill WPI 2200 90% OMC < >

Subgrade WPI 2200, 92% to 98% EMC >

General embankment fill 3m but 3200 90% to 96% EMC ≤ <

General embankment fill 3m 90% OMC > >

Subgrade WPI

>

3200 92% to 98% EMC

General embankment fill 5m WPI 3200 90% to 96% EMC

≤ >

General embankment fill 5m WPI 3200 90% OMC

> > >

Structure Subgrade WPI

<

2200

>

98% EMC

General fill WPI

<

3200 92% to 98% EMC to OMC

Walls Backfill, in trenches 90% to 95% OMC to dry of OMC

Dams Small 94% to 100% OMC to wet of OMC

Large 97% OMC to wet of OMC

>

Landfills Capping 88% to 94% EMC

Liners 94% to 100% OMC to wet of OMC

Canals Clay 90% to 95% OMC to wet of OMC