Geotechnical Engineering

DHARM

210 GEOTECHNICAL ENGINEERING

2.5

2.0

1.5

1.0

0.5

Void ratio e

(arithmetic scale)

PressureskN/m (log scale)^2

10 50 100 500 1000

Fig. 7.6 Pressure-void ratio relationship (Semilog co-ordinates)

7.2.4 Compressibility of Sands

The pressure-void ratio relationship for a typical sand under one-dimensional compression is
shown in Fig. 7.7. A typical time-compression curve for an increment of stress is shown in
Fig. 7.8.

1.2

1.0

0.8

0.6

0.4

Void ratio e

0 200 400 600 800 1000

PressureskN/m^2

Virgincompression

curve

Virgin compression

curve

ReboundRebound curvecurve

Fig. 7.7 Pressure void-ratio relationship for a typical sand

0

20

40

60

80

Compression %

1234 56

100

Time (minutes)

Fig. 7.8 Typical time-compression curve for a sand