UNIAXIAL STRESS AND STRAIN - Introduction to Soft Soil Geotechnique: Content, Context and Application - page 72

TABLE 5.2a DATA PROVIDED

height H [m]
1
1
5

porosity n
0.40
0.42
0.40

weight [kN/m 3 ]
20
17
18

C c
0.006
0.76
0.12

1
2

1
2

1
2

1
2

3 3 3 3

3 0.51

12

1.5

4 4 4 4

5 0.38

21

0.003

5 5 5 5

TABLE ELABORATION FOR = ' = 100 KPA

layer
1
2
3
4
5

e 0
0.667
0.724
0.667
1.041
0.613

0
kPa
20

u
kPa
0

' 0
kPa
10
20
27
27
67
67
73
73
128

1
0.004
0.344
0.297
0.048
0.029
0.292
0.276
0.0007
0.0005

S
m
0.004
0.320
0.192
0.852
0.003
_______
1.371

remark
(1)
(3)

0.00157
0.192
0.0312
0.320
0.00081

10
60
90
140

37
127
163
268

(4)

% z
at the
interface

using
(5.12) at
interface

using
(5.16)

remark n /(1 n ) 0 u (2)

Remarks
- The strain is determined at the top and the bottom of each layer, but at the
ground surface ' 0 = 0 and the formula fails. Therefore, the value in the middle
of the layer is used.
- The settlement, using (5.17) in each layer, is approximated by H (

1 top

)/2. 23
- The strain in layer 2 is larger than 10% and (5.11) should be used which gives a
settlement contribution of H (

bottom

1

1 top 1 bottom )/2 = 1(0.291+0.257)/2 = 0.274 m.

23 Stresses due to weight are (sectionally) linear with depth. Corresponding strain increases
nonlinearly with stress. The settlement (accumulated strain) should in fact be elaborated
accordingly, but it is cumbersome.