Research Journal of Environmental and Earth Sciences 3(4): 433-437, 2011
ISSN: 2041-0492
© Maxwell Scientific Organization, 2011
Received: March 22, 2011
Accepted: April 20, 2011
Published: June 05, 2011
Estimating Compaction Characteristics from Fines in
A-2 Type Lateritic Soils
F.C. Ugbe
Department of Geology, Delta State University, Abraka, Nigeria
Abstract: This study is aimed at quantitatively relating percent fines to compaction characteristics in lateritic
soils. Lateritic soils of western Niger Delta are the major construction material and consequently requires
compaction test before utilization. Fines have profound influence on the compaction characteristics of these
soils. Both compaction and particle size distribution tests were carried out on sixty eight (68) samples.
Compaction characteristics values were plotted against fines percent and different predictive models obtained.
Thirty (30) new samples were obtained within the region and compaction and particle size distribution tests
carried out. Validation of the models using field data yielded correct prediction of 92 and 93% for maximum
dry density and optimum moisture content respectively.
Key words: Compaction, correlation coefficient, fines, Niger Delta
characteristics from simpler geotechnical test that require
relatively smaller quantity of samples.
Johnson and Shallberg (1960) have estimated
compaction characteristics through approximate methods
without recourse to the conventional compaction test.
Winterkorn (1967) employed granulometric principles to
predict compaction characteristics for granular soils.
Kofiatis and Manifopoulous (1982) developed a
parametric relationship for predicting the maximum dry
density of granular soils. Omar et al. (2003) developed
models for the prediction of compaction characteristics
from simpler geotechnical tests on granular soils from
United Arabs Emirates.
No study has so far been carried out to predict
compaction characteristics from a simple particle size
distribution test of lateritic soils within the Niger Delta
region. The study is therefore aimed at attempting a
quantitative relationship between percent fines and
compaction characteristics of the lateritic soils. Attempts
are also made to develop predictive models that may
estimate compaction characteristics of lateritic soils
without going through the laboratory conventional
compaction test procedures.
INTRODUCTION
The study area is part of the western Niger Delta with
longitude 06º13!00" to 06º30!00" E and latitude 05º49!00"
to 06º30!00" N (Fig. 1). The geology of Niger Delta has
been described by various researchers (Short and Stauble,
1967; Allen, 1965; Reijers et al., 1996; Weber and
Daukoru, 1975).
Lateritic soils are quite extensive in the Niger Delta
occurring in the dry flat plains of the region. Figure 2
indicates the geomorphological units of the Niger Delta
with the dry flat plains occurring both in the western and
eastern Niger Delta (Allen, 1965).
Various researchers have established A-2 type
(AASHTO classification) lateritic soils as the dominant
soil group in the dry flat plains of Niger Delta (Arumala
and Akpokodje, 1987; Alabo et al., 1983; Ugbe, 2009).
Akpokodje, (1987) postulated that fines percent
influences compaction characteristics in lateritic soils
within Niger Delta.
These soils are the major road construction material
within the region and consequently requires compaction
test. Compaction test is the most common soil
improvement method. Compaction of a soil is defined as
the process whereby soil particles are constrained to pack
more closely together through mechanical compression
leading to a reduction in air voids (Road Research
Laboratory, 1952; Rahn, 1996).
Compaction test requires appreciably large quantity
of bulk sample. Such samples are sometimes difficult to
obtain in western Niger Delta especially during the wet
season because of the inaccessibility of such terrains. One
way to overcome this problem is to predict compaction
MATERIALS AND METHODS
The soil samples were collected between 1st
September and 1st October 2010. The area covers parts of
Edo and Delta States of Nigeria. The area is accessible
from Benin, Warri and Asaba (Fig. 1).
Sixty-eight (68) soil samples were initially obtained
from the region. The soil samples were first air dried for
fifty days before subjecting them to particle size
433
Res. J. Environ. Earth Sci., 3(4): 433-437, 2011
Fig. 1: Study location map
Fig. 2: The major geomorphic units of the Niger Delta (Adapted from Allen, 1965)
distribution and compaction tests in accordance with
British Standard procedures BS1377 (1990). Compaction
characteristics (Maximum Dry Density (MDD) and
Optimum Moisture Content (OMC)) values and fines
percent are presented in Table 1. Figure 3 indicates the
particle size distribution curve.
The results in Table 1 were then plotted as
compaction characteristics (MDD and OMC) against fines
percent with model equations developed (Fig. 4 and 5).
Thereafter, thirty other different samples within the region
were collected (Table 2) and subjected to the same tests as
the earlier sixty-eight samples to validate the models
developed. The values of the fines percent for these new
thirty samples were plugged into the estimation models to
determine the compaction characteristics. The measured
compaction characteristics were then plotted against the
estimated compaction characteristics and the correlation
coefficient determined (Fig. 6 and 7).
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Res. J. Environ. Earth Sci., 3(4): 433-437, 2011
Fig .3: particle Size Distribution Curve of Soils of Study Area (A-2type)
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
Table 1: Field data of MDD, L.L., OMC and Fines (A-2 type soils)
A - 2 Type
--------------------------------------------------------------------------------OMC (%)
L.L. (%)
Fines (%)
MDD (kg/m3)
1
2000
9.2
33.5
26
2
2050
9.7
29.7
31
3
2040
9.5
38.7
33
4
2020
11.8
44.5
34
5
2030
10.1
35.5
23
6
1940
10.2
37.8
35
7
1930
12.4
43.7
36
8
2000
11.1
45.4
37
9
2010
8.4
29.4
33
10 1940
14
28.8
26
11 2050
8.2
31.2
26
12 2020
8
30.4
27
13 1970
13
43.3
37
14 1930
13
46.5
42
15 1850
13.4
44.2
40
16 2010
10.8
38.8
27
17 2100
8.8
43.8
28
18 2040
10.5
37.1
31
19 2060
10.4
42.5
33
20 2060
8
34.5
21
21 1960
14
44.7
34
22 2080
9.4
43.5
25
23 2040
9.9
27.5
31
24 2050
10.8
37.6
31
25 2030
11.1
38.9
35
26 1870
9.1
33.9
27
27 2120
10.2
39.5
25
28 2000
10.6
36.4
30
29 2040
7.7
40.5
14
30 2090
9.4
22.2
15
31 2060
8
24.5
16
32 2070
8.1
28.5
14
435
2040
2010
2020
2060
2040
1920
2120
2030
2060
1900
2030
2080
2010
2040
2090
2050
1800
1940
1740
2010
1890
1840
1810
1710
2000
2000
1870
2000
1940
2000
1890
1930
1950
1970
1960
1900
9.9
11.2
10.1
9.3
10
8.2
8.3
10.8
10.7
11.8
10.2
9.9
10.2
10.3
10
10.3
8
9.9
10.2
12.1
9.9
9.9
11.1
12
9
12
15
11.5
11.5
11.5
13.5
12
12
11.5
12.5
13.5
36.1
41.6
42.4
22.2
26.4
28.6
34.6
27.4
31.8
38.3
24.5
28.4
33.5
28.5
30.2
37.6
23.5
33.5
30.6
32.3
35.3
27.3
32.3
37.8
27.4
27.3
32
30
34.8
38.3
28.3
34
39
28.3
28.3
33
31
31
29
19
19
22
23
26
31
30
23
25
27
25
25
28
21
32
26
28
28
26
33
30
20
30
25
24
24
30
28
33
29
20
23
30
Res. J. Environ. Earth Sci., 3(4): 433-437, 2011
Table 2: Percent fines, measured and estimated compaction characteristics values
Actual MDD (kg/m3)
S.No.
Percent fines (%)
Estimated MDD (kg/m3)
1
19
2011
2010
2
17
2031
2040
3
19
2011
2005
4
19
2011
2020
5
25
1986
1990
6
20
2004
2010
7
22
1994
2000
8
21
1998
2000
9
22
1994
1990
10
25
1986
1995
11
28
1983
1990
12
27
1984
1980
13
31
1980
1980
14
33
1976
1990
15
30
1982
1990
16
12
2219
2140
17
30
1982
1990
18
32
1979
1980
19
26
1985
1990
20
16
2043
2050
21
25
1986
1990
22
25
1986
2000
23
17
2031
2040
24
18
2364
2170
25
19
2011
2000
26
19
2011
2020
27
23
1990
2000
28
20
2004
2010
29
17
2031
2040
30
22
1994
2000
2250
A-2 Type
Actual MDD (kg/m 3 )
MDD (kg/m 3)
MDD=-0.0295F 3+2.4882F 2 -70,606F+2656.8
2110
2060
2010
1960
1910
1860
1810
1760
1710
14 16 18 20 22 24 26 28 30 32 34 36 38 40 42
Fines (%)
2200
Estimated OMC (%)
9.3
.8
9.3
9.3
9.9
9.4
9.7
9.6
9.7
9.9
10.0
10.0
10.0
10.0
13.0
7.0
13.0
10.1
9.9
8.6
9.8
9.9
8.8
9.1
9.3
9.3
9.8
9.4
8.8
9.7
Actual OMC (%)
9.1
8.6
9.4
9.0
10.2
9.2
9.8
9.7
10.0
10.2
10.2
11.0
10.3
10.1
12.8
7.4
13.1
10.0
9.7
9.0
9.8
9.8
8.6
9.4
9.2
9.5
9.6
9.0
8.9
9.8
y = 0.5257x+952.44
R2 = 0.9208
2150
2100
2050
2000
1950
1950 2000 2050 2100 2150 2200 2250 2300 2350 2400
Estimated MDD (kg/m 3)
Fig. 4: Plot of MDD Versus Fines (A-2 Types)
Fig. 6: Plot of Actual MDD Against Estimated MDD
14.7
13.7
12.7
11.7
10.7
9.7
8.7
7.7
14
Actual OMC (%)
OMC (%)
OMC=0.0005F 3 -0.0441F 3 +1.1375F-3.2852
14 16 18 20 22 24 26 28 30 32 34 36 38 40 42
Fines (%)
12
10
8
6
4
2
0
0
Fig. 5: Plot of OMC Versus Fines (A-2 Types)
RESULTS AND DISCUSSION
2
4
6
8
10
Estimated OMC (%)
12
14
Fig. 7: Plot of Actual OMC Against Extimated OMC
classified as clayey sands. Since they are lacking in
gravels but with appreciable percent of clays, they will
require some form of stabilization for optimum utilization
in road construction.
The particle distribution envelope indicates that these
A-2 type soils are major sands with pockets of gravels not
exceeding 6%. The clay percent ranges between 10 and
20%, silts are below 10%. The soils therefore can be
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Res. J. Environ. Earth Sci., 3(4): 433-437, 2011
their assistance during the laboratory analyses of the soil
samples.
Figure 4 indicates a plot of MDD against fines
percent. Increase in fines percent implies greater porosity
and requires more water for the compaction of the soil.
This therefore reduces density and consequently lowers
the MDD values. A sharp drop in MDD values is noticed
for fines percent between 14- 25%, but remains almost
constant between 26 and 36%. Between 14 and 25% the
soil continues to require more water as a result of
increasing porosity. However, after 25%, the soil
probably achieves its maximum porosity and remains
unaffected by increase in fines percent thereby
maintaining almost constant MDD values.
In Fig. 5, increase in fines percent results in increased
water requirements due to greater specific surface of the
soils. As fines percent increase there seems to be a
significant increase in the optimum moisture content.
Unlike Fig. 4, increase in fines percent progressively
influences optimum moisture content more than maximum
dry density.
Figure 6 and 7 explain the correlation between fines,
MDD and OMC. The high correlation coefficient of 92
and 93% for MDD and OMC respectively indicate that
the estimated values are quite close to the actual
laboratory values. This shows that for A-2 type lateritic
soils, a simple particle size distribution test to obtain fines
percent may be used to predict the compaction
characteristics of these soils within the region.
Compaction characteristics can then be predicted by
the following equations.
REFERENCES
Akpokodje, E.G., 1987. The engineering geological
characteristic and classification of the major
superficial soils of the Niger Delta. Eng. Geol., 32:
205-211.
Alabo, E.H., W.H. Fitzjohn and F.A. Ogare, 1983.
Geotechnical properties of tropical red soil from part
of eastern Niger Delta. J. Min. Geol., 21(1-2): 35- 39.
Allen, J.R., 1965. Late quaternary Niger Delta and
adjacent areas. sedimentary environment and
lithofacies. Am. Assoc. Petrol. Geol. Bull., 49:
547-600.
Arumala, J.O. and E.G. Akpokodje, 1987. Soil properties
and pavement performance in the Niger Delta. Q. J.
Eng. Geol., 20: 287-296.
Johnson, A.W. and J.R. Shallberg, 1960. Factors that
Influence Compaction of Soils. Bulletin No. 272,
Highway Research Board, National Academy of
Sciences, Washington, D.C.
Kofiatis, G.P. and C.N. Manifopoulous, 1982. Correlation
of maximum dry density and grain size. J. Geotech.
Eng. Div-ASCE, 108(GT9): 1171-1176.
Omar, M., A. Shanableh, A. Basma and S. Barakat, 2003.
Compaction characteristics of granular soils in
United Arab Emirates. Geotech. Geol. Eng., 21:
238-295.
Rahn, P.H., 1996. Engineering Geology: An
Environmental Approach. Prentice Hall. New Jersey
US, pp: 275.
Reijers, T.J.A., S.W. Petters and C.S. Nwajide, 1996. The
Niger Delta. In: Reijers, T.J.A. (Ed.), Selected
Chapters on Geology. Shell Petroleum Development
Company, Warri, pp: 103-177.
Road Research Laboratory, 1952. Soil Mechanics for
Road Engineers HMSO, London, pp: 154-207.
Short, K.C. and A.J. Stauble, 1967. Outline of the
geology of Niger Delta. Am. Assoc. Petrol. Geol.
Bull., 51: 761-776.
Ugbe, F.C., 2009. Engineering Geological Properties and
Pavement Construction Qualities of Lateritic Soils
from the Western Niger Delta. Unpublished Ph.D.
Thesis, University of Port Harcourt, Nigeria.
Weber, K.J. and E.M. Daukoru, 1975. Petroleum
Geological Aspects of Niger Delta. Tokyo, 9th world
Petroleum Congress Proceedings, 5(2): 209-225.
Winterkorn, H.F., 1967. Application of granulometric
principles for optimisation of strength and
permeability of granular drainage structures.
Highway Res. Rec., 55(203): 1-7.
MDD = - 0.0295F3 + 2.4882F2 - 70, 606F + 2656.8
OMC = 0.0005F3 - 0.0441F2 + 1.3175F - 3.2852
where, MDD = Maximum dry density
OMC = Optimum moisture content
F = Fines percent
CONCLUSION
The compaction characteristics of lateritic soils from
Western Niger Delta have been found to be dependent on
the fines percent in the soil. Fines percent have been used
to predict compaction characteristics with appreciable
success. Different equations have been developed to relate
fines percent to Maximum Dry Density (MDD) and
Optimum Moisture Content (OMC). The validation of the
models using the field data from the region yielded
correct prediction of 92 and 93% for MDD and OMC,
respectively. The models will aid road construction
engineers to quickly estimate compaction characteristics
without the laborious procedures of compaction test.
ACKNOWLEDGMENT
The Project Manager, Julius Berger Nigeria PLC and
the entire geotechnical laboratory staff of the Railway
project, Delta State Nigeria are highly acknowledged for
437