an engineering geological characterisation of tropical clays - GBV

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8.4 Linear shrinkage
The spatial variation and distribution of values of linear shrinkage determined in this study are
presented in Table (8.1) and Figures (8.7a & b).
Linear shrinkage variation; < 0,5m depth
30
Linear shrinkage (%)
25
20
15
10
5
Profile A
Profile B
Profile C
Profile D
Profile E
0
0 2000 4000 6000 8000 10000 12000
Distance along profile (m)
Fig. 8.7a. Linear shrinkage variation across the study area for the depth of less than 0,50m (north-south distance: 4000 m).
Black clays of less than 0,50m depth generally exhibit little variation in linear shrinkage
values along each of the five field profiles across the study area (Fig. 8.7a); with percentage
values of 24-27, 23-26, 23-29, 24-27 and 23-25 determined for profiles A, B, C, D and E,
respectively. On the whole, soil thicknesses in this depth interval across the study area exhibit
linear shrinkage values of between 23-29%, with a range of 6% as well as mode, median and
mean values of 25%. The distribution is also characterised by a standard deviation of 1,38
and variance of 1,89.
Linear shrinkage variation; 0,50m and more
30
25
Linear shrinkage (%)
20
15
10
5
Profile A
Profile B
Profile C
Profile D
Profile E
0
0 2000 4000 6000 8000 10000 12000
Distance along profile (m)
Figure 8.7b. Linear shrinkage variation across the study area at depths of 0,5m and greater (north-south distance: 4000 m).