Compressibility Characteristics of Fibrous Tropical Peat ... - Ejge.com

Compressibility Characteristics of Fibrous
Tropical Peat Reinforced with Cement
Column
Sina Kazemian
Department of Civil Engineering, University Putra Malaysia, 43400 UPM, Serdang,
Selangor, Malaysia
Email: Sina.Kazemian@yahoo.com
Bujang. B. K. Huat
Department of Civil Engineering, University Putra Malaysia, 43400 UPM, Serdang,
Selangor, Malaysia
Email: bujang@eng.upm.edu.my
ABSTRACT
Peat soil is described as a naturally occurring highly organic substance derived primarily from
plant materials. It is formed when organic (usually plant) matter accumulates more quickly
than it humifies (decay). Various construction techniques have been carried out to support
embankments over peat deposits without risking bearing failures but settlement of these
embankments remains excessively large and continues for many years. Cement columns
method is a method which may exclude settlement problem of peat soil. This study has
investigated the effects of cement columns’ composition on compressibility parameters of
fibrous tropical peat reinforced with cylindrical cement columns; and presents the
compressibility characters of fibrous tropical peat. A comprehensive laboratory work was
carried out in order to study the compressive parameters of fibrous peat stabilized with
various quantities of cement which they were subjected to Rowe Cell Consolidation test. The
results indicate that increasing the cement ratio decrease amount of settlement and
compressibility of tropical peat soil.
KEYWORDS: Peat soil, Fibrous, Cement column, Rowe cell, Coefficient of consolidation,
Compression index, Coefficient of secondary compression, Coefficient of volume
compressibility.
INTRODUCTION
Organic soils are generally formed in natural environments that do not allow for the rapid
decaying of materials (Mesri, 1973).Whole series of products which range from undecayed plant
and animal tissues through ephemeral products of decomposition to fairly stable amorphous
brown to black material bearing no trace of the anatomical structure of the material from which it

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was derived; and it is this latter material that is defined as the soil humus have defined soil
organic matter by Russell (1952).
To a geotechnical engineer, all soils with organic content of greater than 20% is known as organic
soil. Peat soil is an organic soil with organic content of more than 75% (Huat, 2004). This classification
is partly the same as ASTM D 2487 classification; a soil with organic content less than
75% (or ash content more than 25%) as muck or organic soil, while a soil with organic content
higher than 75% (or ash content less than 25%) as a peat. For geotechnical purposes, peat degree
of decomposition or humification system of Von Post (1922) is often reduced to 3 classes
(Magnan, 1980; ASTM Standard D 5715): I. Fibric or fibrous (least decomposed). II. Hemic or
semi-fibrous (intermediate decomposed). III. Sapric or amorphous (most decomposed).
The amorphous peat particles, in which the cell structure is still visible, are the product of
biochemical decomposition and breakdown of fibrous peats and other plant remains. Amorphous
peat deposits are more likely to include a significant amount of inorganic matter. As compared to
fibrous peat deposits, the amorphous peat fabric is likely to exist at lower void ratios and to
display lower permeability anisotropy, lower compressibility, lower friction angle, and higher
coefficient of earth pressure at rest (Edil and Wang, 2000).
Fibrous peat is peat with high organic and fiber content with low degree of humification. The
behavior of fibrous peat is different from mineral soil because of different phase properties and
microstructure (Edil, 2003). Landva and Pheeney (1980), Landva and La Rochelle (1983) described
fibrous peat particles consist of fragments of long stems, thin leaves, rootlets, cell walls, and
fibers, often are quite large. Stem diameters of 20 to 500µm, leaf thicknesses of 10 to 15 µm, and
width and length of 100 to 1,200 µm are common. Scanning electron micro-photographs (SEMs)
of James Bay peat in Figure 1(a), (b) illustrate hollow perforated cellular structures and a network
of fibrous elements in vertical and horizontal section (Mesri and Ajlouni, 2007).
a
b
Figure 1: Scanning electron microphotograph of (a) vertical section; (b) horizontal section (Mesri
and Ajlouni, 2007)
Peat is found in all part of the world except in deserts and the arctic regions. The most extensive
areas are located in the northern hemisphere. It is estimated that there are about 1 billion acres of
peat land in the world or about 4.5% of total land areas. In United State; peat is found in 42 states
with a total area of 50 million hectares, Canada has 110 million hectares and former USSR 150
million hectares. In Japan peat is widely distributed throughout Hokkaido, which is the northern

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of island Japan, with an area of approximately 200 thousand hectares. The total area of tropical
peat swamp forest or tropical peat land in the world amounts to about 30 million hectares
(Deboucha et al., 2008). Various construction techniques have been carried out to support
embankments over peat deposits without risking bearing failures but settlement of these
embankments remains excessively large and continues for many years. Besides settlement,
stability problems during construction such as localized bearing failures and slip failures need to
be considered (Duraisamy et al., 2007-b).
Due to fibrous hollow perforated cellular structures, which it has stated above, the large
compressibility of peat results in a large deformations and strains. Yulindasari (2006) emphasised
the compressibility behavior of fibrous peat is different from that of clay soil. The behavior is
controlled by several factors including the initial water content, fiber arrangement, and fiber
content. The condition in which the fibrous peat is deposited is also an important factor to be
considered. This study is focused on the compressibility characteristics of fibrous peat based on
time-compression curves derived from consolidation tests.
Compressibility Parameters of Fibrous Peat
High organic maters are indicator for high compressibility and swell characteristics of the soils
(Mesri and Ajlouni, 2007; Anand J. et al. 2007; Kazemian et al. 2009). Fibrous peat undergoes
large settlements in comparison to clays when subjected to loading. The compression behavior of
fibrous peat varies from the compression behavior of other types of soils in two ways. First, the
compression of peat is much larger than of other soils. Second, the creep portion of settlement
plays a more significant role in determining the total settlement of peat than of other soil types.
The primary consolidation of the fibrous peat is very rapid, and large secondary compression,
even tertiary compression is observed. Secondary compression is generally found as the more
significant part of compression because the time rate is much slower than the primary
consolidation (Yulindasari, 2006).
Compression of fibrous peat continues at a gradually decreasing rate under constant effective
stress, and this is termed as the secondary compression. The secondary compression of peat is
thought to be due to further decomposition of fiber which is conveniently assumed to occur at a
slower rate after the end of primary consolidation (Mesri et al., 1997).
The main compressibility parameters in soils which were examined to assess the effect of the
cement column to the consolidation parameters of the peat in this paper are: Coefficient of consolidation,
c v , Compression index, C c , Coefficient of secondary compression, C α , Coefficient of
volume compressibility, m v .
EXPERIMENTAL DESIGN AND LABORATORY WORK
This paper is mainly concerned with fibrous peat, and presents an interpretation of the compressibility
parameters of fibrous peat after the installation of cement column with different ratios
cement by using data from Rowe Cell Consolidation test on undisturbed samples of several
fibrous peats taken from Kampung Jawa Klang, Selangor, Malaysia.

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Sample preparation
This study took undisturbed samples of peat soil from Kampung Jawa Klang, Selangor, in
Malaysia with a sampling tube and containers capable of being sealed to prevent the loss or gain
of moisture. Jolting during transports was avoided. The researchers in this study designed and
fabricated a suitable auger with a sampling tube and containers to collect undisturbed peat
samples, as shown in Figure 2. Refer to BS 1377-1 for the preparation methods.
Researchers of this study formed the handle from a 60 cm crossbar and the stem was 100 cm
high. The interior of the cylindrical tube was 150 mm in diameter. It's fitted the upper part of the
hollow cylindrical body with a cover plate and the thin tube with a valve designed to be left open
during sampling to release both air and water pressure. Meanwhile, the lower part of the
cylindrical tube was sharpened to cut roots as the auger slowly rotated into the peat ground during
sampling. The auger’s operators then close the valve prior to the withdrawal of the tube with the
peat sample enclosed, thus providing a vacuum effect to help hold the sample in place. Soon after
the operators withdrew the sampler they sealed the cylindrical tube with paraffin wax.
Once in the laboratory, we opened the top cover of the cylindrical tube to extract the sample. The
auger enables the extraction of peat core samples 150 mm in diameter and 230 mm long. We
trimmed the top and bottom of the specimen. As fibrous soil such as peat is easily disturbed, we
carried out the trimming process carefully and quickly to minimize any change in the soil
sample’s water content. All tests reported here were performed inside a constant temperature
room at 20±2°C.
Figure 2: Sampler fabricated to collect undisturbed peat samples
These procedures, including the setting up of the specimen in the Rowe Cell apparatus, covered
the preparation of a cylindrical test specimen of the original soil sample. The specimens’ heights
and diameters of samples were 50, 150 mm respectively, as shown in Figure 3(a).

Vol. 14, Bund. C
5
a
b
Figure 3: (a) A cylindrical test specimen
from the original soil sample after trimming. (b)
Method used to set up
cement column in specimen.
For preparing the
peat reinforced with cement in order to investigate its compressibility
parameters, this study placed a single PVC tube at the center of the peat specimen
and used it to
remove a portion of the peat soil from the cell and replace it with dry
ordinary Portland cement
mixed
with different amounts of peat soil, the cement-peat ratios tested being 10% %, 20%, 30% %,
and 50% by the air dry weight of the peat
base on BS
1377-1(7.3.4)) (Table 1). The cement
column’s diameter
was 45 mm. The area ratio of column to sample was 0.09 (Figure 3(b)).
Table 1: Various quantities of cement in samples were subjected in this study.
This study then cured the samples for 28
days in a soaking basin with natural peat water
(collected from peat site), as shown in Figure 4(a) and (b), then carried out the compressibility
test on each sample consecutively. In Figure 4(a) and (b), method used for cure peat reinforced
with cement column and taking natural peat water for curing samples are shown respectively.
Peat
water
a
b
Figure 4: (a) Method used to cure peat cement column into specimen (Kazemian et
al. 2008). (b)
Collecting natural peat water for curing the samples.

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Testing programs
The samples were from marine and continental deposits of the Kampung Jawa Klang, Selangor,
west coast of the Malaysian peninsula. They consisted primarily of fibrous organic soils and some
fine-to-medium sands and were dark brown in color.
As mentioned earlier, this study prepared the samples in accordance with BS 1377-1 (1990). We
determined such physical properties of natural soil used in the tests as organic content, water
content, liquid limit, and specific gravity in accordance with BS 1377-3(4) (1990), BS 1377-2(3)
(1990), BS 1377-2(4.3) (1990), and BS 1377-2(8.4) (1990), respectively. We determined the
organic matter (content) of the peat samples based on test procedures according to ASTM D
2974-87, and used the Von Post scale to find the degree of humification (Huat, 2004). Sample
was then tested using Rowe Cell to overcome most of the disadvantages of the conventional
oedometer apparatus when performing consolidation tests on low permeability soils, including
non uniform deposits. The most important features are the ability to control drainage and to
measure pore water pressure during the course of consolidation tests (Duraisamy et al., 2007-a,
2007-b).
Figure 5: Rowe Cell Consolidation test set up used in this study.
The system was comprised of a Rowe Cell Consolidation, gradually diverging system (GDS)
pressure and volume controllers (Figure 5), and GDS laboratory software. The hydraulic loading
system pressure and vertical loads (50, 100, 200 and 300kPa) can be applied to the sample surface
either via a flexible diaphragm to give a uniformly distributed pressure (free strain) or via a rigid
plate to give uniform settlement (equal strain). The bottom drain is provided with a tapping to a
pressure transducer.
This study performed the consolidation tests on low permeability soils on the peat based on BS
1377-6 1990 and determined the compressibility parameters of the samples without having to remove
them from their sampling tubes. The samples therefore didn’t suffer disturbance due to
their preparation, and the moisture content of the soils at the respective test horizons could be
reported.
The compressibility parameters in soils which were tested to assess the effect of the cement
column with different cement ratio, to the consolidation parameters of the peat in this study are:
1. Coefficient of consolidation (C v ) 2. Compression index (C c ) 3. Coefficient of secondary compression
(C α ), and 4. Coefficient of volume compressibility (m v ).

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RESULTS AND DISCUSSION
Physical characteristics of Untreated (Natural) Peat
This study performed the basic tests on natural fibrous tropical peat soil. Table 2, with some
characteristics and indications of the concentration at which all of the studied organic compound
are usually found in soils. It obtained a range of values almost in line with such other researchers
as Ajlouni (2000), Huat (2004), Duraisamy et al. (2007-a) and (2007-b), Alwi (2007), Kazemian
et al. (2009), Kalantari and Huat (2009).
Table 2: Physical characteristics of the tested soil (untreated peat)
Coefficient of consolidation (C v )
There is a significance decrease in the coefficient of consolidation of the undisturbed samples
with an increase in effective stress above the apparent pre-consolidation pressure (σ c ) (Huat,
2004). Farrell et al. (1994) reported this decrease is more marked in the samples, which had the
higher organic contents. The coefficient of consolidation for a particular pressure from
consolidation test can be determined by curve fitting methods by using two methods:
1. The logarithmic time (Cassagrande’s) method; and
2. The square root time (Taylor’s) method.
For fibrous peat, the results indicate that the coefficient of consolidation (C v ) decreased by
increasing the load (consolidation pressure) and cement ratio simultaneously. The coefficient of
consolidation was decreased around 40%, by increasing consolidation pressure and cement ratio
to 300kPa and 50%, respectively (Figure 6).

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Coefficient of consolidation, Cv
(m²/year)
5.4
4.9
4.4
3.9
3.4
2.9
2.4
1.9
0 100 200 300 400
Consolidation Pressure (kPa)
Untreated Peat
Sample A
Sample B
Sample C
Sample D
Figure 6: Coefficient of consolidation versus consolidation pressure.
Compression index (C c )
The rate of compression index in the standard consolidation test can be defined by the slope (C c )
of the final part of the void ratio versus logarithmic of load (log p) curve. Based on Figure 7, the
compression index (C c ) values from Rowe Cell consolidation test for the natural fibric peat,
sample A, B, C, and D; were 1.809, 1.723, 1.467, 1.343, and 1.098 respectively, for consolidation
pressure of 50 kPa. It means by increasing the cement ratio the compression index (C c ) is
decreased gradually. The fibrous reinforced peat is cured in water peat that’s why; it obtained a
little different of values with such other researchers.
2.1
Compresion Index, Cc
1.8
1.5
1.2
0.9
0.6
0 10 20 30 40 50 60
Cement Ratio (%)
Figure 7: Compression index versus cement ratio in peat soil.
Coefficient of secondary compression, Cα
For the following three reasons, secondary compression and associated settlement are often more
significant for peat deposits than other geotechnical materials: (1) fibrous peat deposits display
the highest values of Cc; (2) fibrous peat deposits have the highest values of C α /C c ; and (3)
primary consolidation of fibrous peat layers in the field is completed commonly within a few
weeks or months (Mesri and Ajlouni, 2007). Primary consolidation and secondary compressions
can take place simultaneously. However, it is assumed that the secondary compression is
negligible during primary consolidation, and is identified after primary consolidation is
completed (Lefebvre et al., 1984; Hobbs, 1986; Kogure et al., 1986).

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Ratio of compressibility, Cα/Cc
0.15
0.135
0.12
0.105
0.09
0.075
0.06
0.045
0.03
0.015
0
0 100 200 300 400
Consolidation Pressure (kPa)
Untreated Peat
Sample A
Sample B
Sample C
Sample D
Figure 8: Ratio of compressibility versus consolidation pressure.
The coefficient of secondary compression C α was determined from the slope of the e-log (t)
curves during the period of 4 to 24 hours after load increment, assuming that the secondary
compression would have started 4 hours after loading. The soil with C α /C c values of more than
0.064 is classified as soil with extremely high secondary compressibility (Merci, 1973).
Secondary compression behavior of soils is completely explained and predicted by the C α /C c law
of compressibility (Mesri and Godlewski 1977, 1979; Mesri and Castro 1987; Mesri 1987; Mesri
et al. 1994, 1997).
Figure 8 depicts the measured ratio of compressibility (C α /C c ) of untreated fibrous peat and
reinforced fibrous peat by cement column. Ratio of compressibility of peat is increased by
increasing the consolidation pressure subsequently from 0.0678 to 0.1038 for 50 to 300 kPa
consolidation pressure respectively. On the other hand, the ratio of compressibility (C α /C c ) is
influenced with the addition of cement and it is declined. E.g., the low of compressibility (C α /Cc)
is declined from 0.0678 to 0.039 for untreated soil by adding cement 50% for consolidation
pressure of 50 kPa and it is decreased from 0.1038 to 0.0774 for consolidation pressure of 300
kPa too (Figure 8).
Coefficient of volume compressibility (m v )
This parameter is very useful to estimate the primary consolidation settlement. The e-p’ curve is
used to obtain coefficient of axial compressibility a v and thus the coefficient of volume
compressibility m v , while the e-log p’ is used to obtain compression index, C c and preconsolidation
pressure (σ’ c ).
The coefficient of volume compressibility (m v )-consolidation pressure relationship, as shown in
Figure 9, exhibits coefficient of volume compressibility is gradually decreased by increasing the
consolidation pressure and cement ratio. Because of the hardened skeleton matrix formed by
cement particles bonding with adjacent soil particles in the presence of water in its pores, the
compressibility characters of soils is improved. E.g., the coefficient of volume compressibility
(m v ) is declined from 1.48E-3 to 0.98E-3 for untreated soil by adding cement 50% for consolidation
pressure of 50 kPa.

Vol. 14, Bund. C 10
Coefficient of compressibility,
mv (m2/MN)
1.6
1.2
0.8
0.4
0
0 100 200 300 400
Consolidation Pressure (kPa)
Untreated Peat
Sample A
Sample B
Sample C
Sample D
Figure 9: coefficient of volume compressibility versus consolidation pressure.
It should be noted that, the declining of the coefficients of volume compressibility gradually,
means the minimum consolidation pressure in this study (50kPa) is more than pre-consolidation
pressure samples. Otherwise, due to consolidation pressure is lower than the pre-consolidation
pressure, the soil sample swell then lower value was obtained for the coefficient of volume
compressibility (m v ) under consolidation pressure of 50 kPa.
CONCLUSIONS
This study was conducted to explore the influenced of the various quantities of cement on
compressibility parameters of fibrous peat by installing a cement column in undisturbed soils. In
all, 4 cement ratio (10, 20, 30, and 50%) were added to undisturbed fibrous peat soil which taken
from below the water table, as well as laboratory and field data on fibrous peats from the
literature.
The specimens were then cured in water which was collected from the peat site. Then, compressibility
behavior of the peat soil was determined by Rowe Cell consolidation test for both the
natural (untreated) and reinforced fibrous peat by cement columns for consolidation pressure 50,
100, 200, and 300 kPa.
The following conclusions are based on the analyses, data, and interpretation presented in this
paper:
1. The coefficient of consolidation (C v ) is in the range of 4.95-2.78 (m 2 /year) and 4.21-2.05
(m 2 /year) for untreated peat soil and reinforced peat soil by cement 50% for consolidation
pressure of 50-300 kPa, respectively. The coefficient of consolidation is decreased by increasing
the load and cement ratio simultaneously.
2. The compression index (C c ) values from Rowe Cell consolidation test for the natural fibric
peat, sample A, B, C, and D; were 1.809, 1.723, 1.467, 1.343, and 1.098 respectively, for
consolidation pressure of 50 kPa. It means by increasing the cement ratio the compression index
(C c ) is decreased gradually.
3. The ratio of compressibility (C α /C c ) of peat is increased by increasing the consolidation
pressure, in addition, it is influenced with the addition of cement and it is declined. The low of

Vol. 14, Bund. C 11
compressibility (C α /C c ) is in the range of 0.0678-0.1038 and 0.039-0.0774 for untreated peat soil
and reinforced peat soil by cement 50% for consolidation pressure of 50-300 kPa, respectively.
4. The coefficient of volume compressibility (m v ) is in the range of 1.48-0.656 (m 2 /MN) and
0.98-0.412 (m 2 /MN) for untreated peat soil and reinforced peat soil by cement 50% for
consolidation pressure of 50-300 kPa, respectively. The coefficient of volume compressibility is
gradually decreased by increasing the consolidation pressure and cement ratio.
5. Because of the hardened skeleton matrix formed by cement particles bonding with adjacent soil
particles in the presence of water in its pores, the compressibility characters of soils such as
C α /C c , C c , C v , and m v are improved; then settlement of fibrous peat decreased.
6. The results survey of compressibility characters of reinforced fabrious peat samples in this
study and literatures show, the ground water in peat land has negative affected on compressibility
parameters of reinforced fabrious peat, in comparison of sample curing in pure water.
REFERENCES
1. Alwi, A. (2007) “Ground Improvement on Malaysian Peat Soils Using Stabilized
Peat-Column Techniques,” PhD. Thesis engineering faculty of University Malaya,
Kuala Lumpur.
2. Ajlouni, M. A. (2000) "Geotechnical Properties of Peat and Related Engineering
Problems," Thesis, University of Illinois at Urbana-Champaign.
3. Anand J. Puppala, Sharmi P. Pokala, Napat Intharasombat, and Richard
Williammee (2007) "Effects of Organic Matter on Physical, Strength, and Volume
Change Properties of Compost Amended Expansive Clay," Journal of Geotechnical
and Geoenvironmental Engineering, ASCE, U.S.A., Vol. 133, No. 11.
4. A.S.T.M. (1992) “American Society for Testing and Materials Annual,”
Philadelphia, PA., U. S. A.
5. B.S. 1377 (1990) “Soils for Civil Engineering Purposes,” British Standard
Institution (BSI.), London, U. K.
6. Deboucha, S., Hashim, R. & Alwi, A. (2008) "Engineering Properties of Stabilized
Tropical Peat Soils," The Electronic Journal of Geotechnical Engineering (EJGE).
Vol. 13, Bund. E.
7. Duraisamy, Y., Huat, B.B.K. Aziz A.A. (2007-a) "Compressibility Behavior of
Tropical Peat Reinforced with Cement Columns," American Journal of Applied
Sciences, 4 (10): 768-773.
8. Duraisamy, Y., Huat, B.B.K. Aziz A.A. (2007-b) "Engineering Properties and
Compressibility Behavior of Tropical Peat Soil," American Journal of Applied
Sciences, 4 (10): 786-791.
9. Edil, T. B. (2003) "Recent Advanced in Geotechnical Characterization and
Construc-tion over Peat and Organic Soils," In Proceeding of 2nd Int. Conf. on
Advances in Soft Soil Eng. and Tech., ed. Huat et al., Putra jaya, Malaysia, 3-25.

Vol. 14, Bund. C 12
10. Edil, T. B., and Wang, X. (2000) “Shear Strength and K0 of Peats and Organic
Soils,” Geotechnics of high water content materials, ASTM STP 1374, West
Conshoho-cken, Pa., 209–225.
11. Hobbs, N. B. (1986) "Mire Morphology and the Properties and Behavior of Some
British and Foreign Peats," Q. I Eng. Geol., London, 19(1): 7-80.
12. Huat, B.B.K. (2004) "Organic and Peat soil Engineering," University Putra Malaysia,
Serdang, Malaysia.
13. Kalantari, K. & Huat, B.B.K. (2009) "Precast Stabilized Peat Columns to Reinforce
Peat Soil Deposits," The Electronic Journal of Geotechnical Engineering (EJGE).
Vol. 14, Bund. B.
14. Kazemian, S., Huat B. B. K., Jit Ming Yeong & Vahed, G. (2008) "Laboratory
Investigations on Shear Strength of Organic Soils and Peat Reinforced with Cement
Columns," Proc. of Int. Graduate Con. on Eng. and Sci. (IGCES) UTM, Johor Bahru,
Malaysia.
15. Kazemian, S., Asadi, A. and Huat, B.B.K. (2009) "Laboratory Study on Geotechnical
Characterization of Tropical Organic Soils and Peat," International Journal of
Geotechnics and Environment. January, issue 1.
16. Kogure, K., Yomuguchi, H., Ohira, Y. and Ishioroshi, H. (1986) "Physical and
Engineering Properties of Peat Ground," Proceeding Advances in Peat land
Engineering. Ottawa, Canada, 95-100.
17. Landva, A. O., and La Rochelle, P. (1983) “Compressibility and Shear
Characteristics of Radforth Peats,” Testing of peat and organic soils, STP 820,
ASTM, West Conshohocken, Pa., 157–191.
18. Landva, A. O., and Pheeney, P. E. (1980) “Peat Fabric and Structure,” Canadian
Geotechnical Journal, 17(3), 416–435.
19. Lefebvre, G. K., Langlois, P., Lupien, C. and Lavallde, J. G. (1984) "Laboratory
Testing and in-situ Behavior of Peat as Embankment Foundation," Canadian
Geotechnical I., Ottawa, Canada, 21(2): 101-108.
20. Magnan, J. P. (1980) "Classification Geotechnique Des Sols: 1- A Propos De La
Classification LPC," Bulletin de Liaison des Laboratories des Ponts et Chaussees,
Paris, 19-24.
21. Mesri, G. & Ajlouni, M. (2007) “Engineering Properties of Fibrous Peats,” Journal of
Geotechnical and Geoenvironmental Engineering, ASCE, U.S.A., Vol. 133, No. 7.
22. Mesri, G. (1973) Coefficient of Secondary Compression,” J. Soil Mech. and Found.
Div., 99(1), 123–137.
23. Mesri, G. (1987) “Fourth law of soil mechanics: A law of compressibility,” Proc., Int.
Symp. on Geotechnical Engineering of Soft Soils, Vol. 2, M. J. Mendoza and
Montañez, eds., Sociedad Mexicana de Mecánica de Suelos, Coyoacán, Mexico,
179–187.
24. Mesri, G., and Castro, A. (1987) “The Cα/Cc concept and Ko during secondary
compression,” Journal Geotechnical Engineering, 113 (3), 230–247.

Vol. 14, Bund. C 13
25. Mesri, G. and Godlewski, P. M. (1977) "Time and Stress Compressibility
Interrelationship," Journal of Geotechnical Engineering, ASCE, 105 (1), 106-113.
26. Mesri, G., and Godlewski, P. M. (1979) “Closure to Time and stress compressibility
interrelationship,” Journal Geotechnical Engineering Div., 105 (1): 106–113.
27. Mesri, G., Feng, T. W., Ali, S., and Hayat, T. M. (1994) “Permeability characteristics
of soft clays,” Proc., 13th Int. Conf. on Soil Mechanics and Foundation Engineering,
Vol. 2, Balkema, Rotterdam, The Netherlands, 187–192.
28. Mesri, G., Stark, T. D., Ajlouni, M. A., and Chen, C. S. (1997) “Secondary compression
of peat with or without surcharging,” Journal Geotechnical Geoenvironmental
Engineering, 123 (5), 411–421.
29. Russell, E. J. (1952) "Soil Conditions and Plant Growth," 8th edition, Longmans,
Green and Co., London.
30. Yulindasari (2006) "Compressibility Characteristics of Fibrous Peat Soil," Master of
Engineering (Geotechnics) thesis, Universiti Teknologi Malaysia.
31. Von Post, L. (1922) "Sveriges Geologiska Undersoknings Torvinventering Och
Nagre av Dess Hittills Vunna Resultat, Sr. Mosskulturfor," Tidskr 1: 1-27.
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