UNIAXIAL STRESS AND STRAIN - Introduction to Soft Soil Geotechnique: Content, Context and Application - page 74

' 1 = 18 kN/m 3 , ' 2 = 20 kN/m 3 , 100m, h = 30m, L = 1000m, C c /(1+ e 0 ) = 0.1, =

50kPa.

stiff stiff

H H

soft soft

stiff stiff

h h

L L

x x

Figure 5.4

application 5.7
A soft clay site is to be prepared for development by applying a surcharge sand
fill of 2m thick (Fig 5.5). Determine the final level of the sand fill relative to
N.A.P. Thickness soft clay is 6m. Groundwater level: 1m below surface (Fig 5.5).
The wet unit weight soft clay is 14 kN/m 3 . The dry unit weight sand: 16 kN/m 3 .
Take: = 0.15 and n = 40%. NAP: basic level (standard).

Hint. Take an average value of initial effective stress at one-third depth in the
soft clay. Perform two calculation cycles, the first without submergence correction,
the second with submergence correction based on the first calculation. Then
average both results.

sandfill sandfill

NAP NAP 1.0m 1.0m

NAP NAP 2.0m 2.0m

groundwater table groundwater table

soft clay soft clay

NAP NAP 7.0m 7.0m

Figure 5.5