![The properties of Al-Adhaim Dam soils (After [25])](https://www.researchgate.net/profile/Nabeel-Mahmood-5/publication/361090864/figure/tbl1/AS:11431281104821231@1670264310089/The-properties-of-Al-Adhaim-Dam-soils-After-25_Q320.jpg)
Content uploaded by Nabeel S. Mahmood
Author content
All content in this area was uploaded by Nabeel S. Mahmood on Jan 28, 2025
Content may be subject to copyright.
102
SLOPE STABILITY AND SOIL LIQUEFACTION ANALYSIS OF
EARTH DAMS WITH A PROPOSED METHOD OF GEOTEXTILE
REINFORCEMENT
Samar Abdulhameed Aude1, Nabeel Shakir Mahmood2, Sadeq Oleiwi Sulaiman3, Hasan Hussain Abdullah4
and *Nadhir Al Ansari5
1College of Engineering, University of Kalamoon, Syria; 2,3College of Engineering, University of Anbar,
Iraq; 4Ministry of Water Resources, Iraq; 5 Civil, Environmental and Natural Resources Engineering, Lulea
University of Technology, Sweden
*Corresponding Author, Received: 16 June 2021, Revised: 05 Feb. 2022, Accepted: 02 April 2022
ABSTRACT: Dam projects require comprehensive studies and a careful implementation process; thus, the
causes of the possible failure, during the construction or operation of dams, should be thoroughly investigated.
Specifically, geotechnical analysis of seepage, static stability, and seismic stability is essential to be evaluated.
Earthquakes shaking imposes additional hysteric and short-term loads in the two directions that may cause
serious problems and may lead to dam failure due to settlement, piping, high pore water pressure, and soil
liquefaction. In this study, Geo-Studio 2018 software was utilized to evaluate the slope stability and the seepage
analysis of Al-Adhaim Dam in Iraq. The dynamic stability of the dam and the soil liquefaction were also
evaluated as a result of applying earthquake shaking to the dam. The results obtained from the analysis
indicated that the dam was stable in the static condition. Furthermore, the results of the dynamic condition
indicated that an earthquake, with an acceleration value of 0.38g and 10 seconds period, caused a vertical
displacement of the dam of 0.12 m and reduced the factor of safety to 1.01 which was less than the allowable
value. Therefore, geotextile reinforcement was suggested to reduce the effect of the soil liquefaction that was
observed in the front shell of the dam. As discussed herein, the reinforcement increased the dam stability as
the factor of safety of the dam increased to 1.946 which was within the allowable values.
Keywords: Earth dams, Earthquake, Geo-Studio, Slope Stability, Liquefaction
1. INTRODUCTION
The static design method is one of the oldest
methods that has been used in geotechnical
engineering. The slope stability theory, according to
a sliding mass divided into slices, was first applied
at the beginning of the Twentieth Century for safety
factor calculations and the method was then
developed by Fellenius, Janbu, and Bishop. With
the aid of advanced software and finite elements
methods, new methods such as Morgenstern-Price
and Spencer have been devolved by using iterative
procedures [1, 2]. The purpose of slope stability
studies is to calculate the slope factor of safety. The
stability of the slope is determined by comparing
the calculated values of the safety factor to the
correspondent values from the relevant codes [3–5].
Because possible failure of dams may cause great
human and economic losses, it is essential to study
the dynamic analysis and slope stability of the dams
due to the seismic loads which depend on the static
analysis of the dam before the earthquake shaking
[6–8]. Earthquakes cause a serious threat to the
stability of the dams as the statistics indicated that
complete or partial failure of earth dams due to
earthquakes is caused by 1) dam settlement which
leads to transfer cracks; 2) internal erosion and
piping inside the dam that may lead to dam failure
when filter systems are not well designed, and 3) the
rise of pore water pressure that may lead to soil
liquefaction which represents the greatest danger on
the dam stability [9–11]. The possibility of the
occurrence of the aforementioned problems
depends on many factors such as the intensity of the
earthquake, the construction materials of the
foundations, the topographic conditions of the dam
site, dam type, water level of the dam reservoir, and
the freeboard [12–14]. Therefore, it is necessary to
study the specific conditions for the dam site and the
seismic conditions of the site. Sawada et al. [15]
discussed the behavior of small earthen dams under
seismic loads. The upstream and downstream sides
of an earth dam were stabilized with a
polypropylene geotextile. The results showed that
the effective stress of the materials on the upstream
side significantly increased, despite the observed
deformations of these materials being greater than
that of the downstream materials. Furthermore, a
large difference in the phase of the measured
acceleration was observed between the upstream
slope and downstream slopes. The purpose of the
dynamic design of dams is to calculate the values of
International Journal of GEOMATE, June, 2022, Vol.22, Issue 94, pp.102-112
ISSN: 2186-2982 (P), 2186-2990 (O), Japan, DOI: https://doi.org/10.21660/2022.94.j2241
Geotechnique, Construction Materials and Environment
International Journal of GEOMATE, June, 2022, Vol.22, Issue 94, pp.102-112
103
dynamic safety factors and pore water pressure
development during earthquake shaking and to
compare these values with the allowable values.
The shape of the circular slip surface from the
dynamic design is similar to that of the static design.
However, the vertical and horizontal forces values,
which result from the earthquake acceleration and
excess pore water pressure, are added to the
equation that calculates the static factor of safety to
calculate the dynamic factor of safety. The dynamic
analysis depends on the static stresses of the dam at
the time of the earthquake occurrence [16–20].
Soil liquefaction is defined as the phenomenon
that highly reduces soil shear strength and causes
large deformations when the pore water pressure
increases due to cyclic loading. Saturated sand, silty
sand, gravelly sand are the most vulnerable soils to
liquefaction. The permeability of gravel is high
enough to dissipate excess pore water pressure
unless gravel presents within a fine-grained soil that
prevents the dissipation. Many methods have been
developed to evaluate the liquefaction potential of
different types of soils based on plasticity, grain size
distribution, and actual moisture in the field [21–24].
This study consists of evaluating the current
condition of the dam and its stability during
earthquakes events, proposing a solution for the
possible liquefaction, and discussing the effects of
this solution on the dam stability. Geotextile
reinforcement is an economical, easy, and
frequently used method for earthworks and road
projects. The cost of this method was not calculated
in this research because it depends on many other
factors, but in general, the use of geotextile for
earthwork applications is cost-effective compared
to the total cost of the project. The GeoStudio
Model, for studying the equilibrium of slopes
(GeoSlope), determines the shearing forces
affecting the slopes of the dam, calculates the shear
strength and pore water pressure values during
periodic loading during the earthquake. It also
determines the areas of soil liquefaction within the
slope.
The main objective of this research is to conduct
analysis and molding for an earth dam under
operation (Al-Adhaim Dam) by using Geo-Studio
2018. The dam area is seismically active as many
lights and moderate earthquakes have recently hit
the area. These recent earthquakes may indicate a
possible occurrence of a major earthquake within
the dam area. Therefore, the resistance of the dam
to earthquakes should be evaluated to avoid the
possible causes of failure. Seepage and pore water
pressure in the dam and the foundations were
calculated by using SEEP/W software. The
obtained values were then used to calculate the
factor of safety of the static condition by using
Slope/W to evaluate the dam before the earthquake.
A dynamic study was tperformed by using
Quake/W to evaluate the dynamic factor of safety
and the vulnerable liquefaction zones caused by an
earthquake. Geotextile reinforcement was proposed
to keep the dam safe during earthquakes.
2. MATERIALS AND METHODS
For an adequate study of the stability of dams,
the study should be comprehensive that include all
the different conditions of operation. Therefore, the
current study includes the following conditions:
1- Study of the static stability and seepage at the
maximum storage and steady-state seepage.
2- Study of the stability during rapid drawdown.
Water level increases the stability of the front face
of the dam when the storage is maximum with the
steady-state flow. In case the drawdown of the
reservoir is higher than the water dissipation from
the dam, the excess pore water pressure inside the
dam will increase and cause soil liquefaction.
Similar behavior will occur during earthquakes.
3- Dynamic stability during earthquakes.
4- Suggest solutions to prevent dam failure.
2.1 Numerical Model
Many numerical models have been developed to
analyze the stability and seepage of dams such as
Geo-Studio, Plaxis, and FLAC. Geo-Studio
includes a package of software to analyze many
aspects of dams under different loading conditions.
In this study, the stability was analyzed by using
SLOPE/W based on the Morgenstern-Price method
at different loading conditions. The static analysis
was with a steady-state of seepage and with
transient seepage during the rapid drawdown.
QUAKE/W was used to evaluate the safety factor
as an earthquake shaking was applied, based on the
initial static condition.
2.2 Study Area and Data Collected
Al-Adhaim Dam was used as a case study which
is located on the Al-Adhaim River 133 km northeast
of Baghdad within Diyala Province in Iraq. It is
located within the coordinates 34°33′54″N and
44°30′56″E as shown in Fig.1. Al-Adhaim
dam is a multi-purpose earth dam as it is used to
control the flooding of the Al-Adhaim River,
provide the quantities of water needed to irrigate the
cultivated areas in the Al-Adhaim Basin, as well as
be used in generating electricity. Its storage
capacity is about 1.5 billion cubic meters. The dam
consists of shells constructed of sand-gravel soils, 8
m inclined clay core, and two layers of filters, as
presented in Fig.2. The main properties of the earth
fill materials are presented in Table 1. The
maximum storage level is 131.5 m [25–28].
International Journal of GEOMATE, June, 2022, Vol.22, Issue 94, pp.102-112
104
Fig.1 The location of the study area in Diyala Province in Iraq
Fig.2 The cross-section of Al-Adhaim Dam
3. RESULTS AND DISCUSSION
3.1 Static Analysis of the Dam Before
Earthquake Shaking
The static analysis of the dam before the
occurrence of the earthquake shaking is
summarized in the following steps:
1- Seepage Study: Seepage through the dam and the
foundations may cause piping, increase pore water
pressure, and reduce soil shear strength. These
changes may cause serious problems to the stability
of the dam. SEEP/W was used to study the seepage
at the maximum storage with the steady-state flow
to determine the seepage line and pore water
pressure inside the dam, as shown in Fig.3.
2- Slope Stability Study: SLOPE/W was used to
calculate the static factor of safety for the front and
backside of the dam based on the values of pore
water pressure that were obtained from the analysis
with SEEP/W. The calculated values of the factor
of safety were 1.882 for the front face and 1.849 for
the back face, as shown in Fig.4 and Fig.5,
respectively.
International Journal of GEOMATE, June, 2022, Vol.22, Issue 94, pp.102-112
105
Table 1. The properties of Al-Adhaim Dam soils (After [25])
Material zone Modulus of
Elasticity
[ MN/m2]
Permeability
[m/sec]
Poisson's
Ratio
Unit
Weight
[kN/m3]
Cohesion
[kN/m2]
The angle of
Internal
Friction
[degrees]
Shell
19
1.25x10-5
0.3
17.658
0
37
Core
30
2.25x10-10
0.45
19.62
60
23
Filter F 19 1.2x10-5 0.3 18.658 0 35
Filter T
19
1x10-4
0.3
18.658
0
35
Foundation on
Marl
350 1x10-10 0.35 20.601 600 10
Foundation on
Sandstone
300 5.5x10-8 0.35 20.601 0 38
Fig.3 Analysis of seepage by using SEEP/W
Fig.4 Slope stability analysis for the front face of the dam
International Journal of GEOMATE, June, 2022, Vol.22, Issue 94, pp.102-112
106
Fig.5 Slope stability analysis of the dam back face
3- Study of Seepage and Stability as a Result of
Rapid Drawdown: Earthquakes cause cyclic motion
of the water in the dam reservoir. When the storage
water level increases during the earthquake, water
will flow toward the back face of the dam. However,
when the water level suddenly decreases in a short
time, the flow will be reversed towards the front
face which highly decreases the factor of safety.
Therefore, seepage was analyzed due to the change
in the water level within 10 seconds period by using
SEEP/W for the transient condition. The variation
of the safety factor caused by the rapid drawdown
is as presented in Fig.6. The value of the factor of
safety obtained from the analysis was 1.834.
Fig.6 The variation of the factor of safety as a result of the rapid drawdown
3.2 The Static Analysis of the Initial Stresses
The static analysis was performed before the
earthquake to evaluate the initial stresses and pore
water pressure. Fig.7 shows the total stress at the
maximum storage, and the value of the factor of
safety for the front face based on the static stresses
is shown in Fig.8. The results obtained from slope
stability analysis at the static condition for Al-
Adhaim Dam are presented in Table 2. The results
were compared with the allowable values, as
presented in the design guidelines of USACE 2003
[29]. It can be seen that the dam is stable under the
different loading conditions.
3.3 The Dynamic Analysis of the Dam
The dynamic analysis of the dam was performed by
using Queke/W as the stresses were evaluated
during the earthquake based on the static analysis as
an initial state. The dam was placed under the
vertical and horizontal components of the ground
motion with peak ground acceleration (a max) of
0.38g and a period (T) of 15 seconds, as shown in
Fig.9. The ground motion parameters were obtained
International Journal of GEOMATE, June, 2022, Vol.22, Issue 94, pp.102-112
107
from the available data of the seismic activity of the
dam area.
The total and effective stresses were determined
from Queke/W. As shown in Fig.10, the value of the
perpendicular displacement that resulted from the
earthquake shaking, was 0.21 m at the top of the
dam. The relative displacement of the dam during
the earthquake shaking was as high as 0.4 m at 9
seconds, as shown in Fig.11. Slope/w was then used
to determine the dynamic factor of safety. As shown
in Fig.12, the minimum value of the dynamic factor
of safety was 1.01 at T of 10 seconds. The values of
the safety factor at any time during the shaking are
presented in Fig.13. The minimum safety factor
value by, using the dynamic analysis, was 1.2. The
variation of the factor of safety, for the critical slip
surface of the front face, with the values of the
acceleration are shown in Fig.14. The safety factor
was less than the allowable value (1.2) when the
value of acceleration was 0.12 g.
Fig.7 Initial stresses at the maximum storage
Fig.8 The factor of safety for the front face as evaluated from the static stresses
Table 2. The results obtained from the static stability analysis
Dam evaluation
USACE 2003
Limits
The factor of safety
for the back face
The factor of safety
for the front face
Static loading
Stable 1.5 1.848 1.882 Maximum storage
Stable 1.5 1.850 1.881 No storage
Stable
1.2
-
1.834
Rapid drawdown
International Journal of GEOMATE, June, 2022, Vol.22, Issue 94, pp.102-112
108
Fig.9 Peak ground acceleration for the dam site
Fig.10 Displacement values and shapes after the earthquake shaking
Fig.11 Relative displacement during the earthquake
Fig.12 Minimum factor of safety during the earthquake at the maximum storage of the reservoir
International Journal of GEOMATE, June, 2022, Vol.22, Issue 94, pp.102-112
109
Fig.13 The variation in the factor of safety of the front face of the dam during the earthquake shaking
Fig.14 The variation of the values of the factor of safety with the average acceleration
3.4 Soil Liquefaction
As shown in Fig.15, liquefaction was observed
in the front shell due to the earthquake shaking. It
can be seen that earthquake-triggered liquefaction
was developed within the upstream slope as the soil
lost its shear strength. Specifically, the liquefaction
zone was observed in the lower part of the slope and
near the face of the slope as the soil within this zone
is likely to be fully saturated and can densify during
the shaking. The zone is at unacceptable risk of flow
failure.
3.4 Geotextile Reinforcement
Geotextile reinforcement was suggested to
support the liquefiable soil on the front face of the
dam, as presented in Fig.16. The suggested
geotextile reinforcement is to be placed in
horizontal layers according to the following
specifications:
1- The vertical spacing between the layers is 5 m.
2- The length of the geotextile layers is 20 m.
3- The geotextile layers extend from the face of the
front shell of the dam.
4- The geotextile layers were placed within the zone
that is vulnerable to liquefaction, as presented in the
aforementioned analysis.
Geotextile installation is an easy process when the
appropriate tools are available. The geotextile layer
is added within the embankment fillings at the front
and back of the dam. The dam embankment layer
should be leveled properly, all the protruding
objects must be removed from the face of the layer
and the geotextile layer is laid according to
engineering drawings. The process of stretching the
geotextile layer must be done tightly to keep it level
and flat. The ends of adjacent layers shall be
overlapped at the same site and fixed at the overlap
sites and the edges using staples, soil, or other
suitable materials. The next layer of earth
embankment dictates is placed directly on the
geotextile layer, with a thickness ranging from 100
mm to 300 mm or more, according to the required
engineering specifications and soil type, and the soil
is compacted until the required density of the soil is
reached. The strength values of the utilized
geotextile material areas are listed in Table 3.
The value of the factor of safety increased to 1.946
after using the geotextile reinforcement. Fig.17
shows the shape of the critical circle. The values of
the factor of safety during the earthquake shaking,
after using the reinforcement, are presented in
International Journal of GEOMATE, June, 2022, Vol.22, Issue 94, pp.102-112
110
Fig.18. The geotextile increased the stability of the
slope during the earthquake shaking as the value of the factor of safety increased to a maximum value
of 1.966 at T of 6 seconds.
Fig.15. Liquefiable zones of the dam
Figure 16. Geotextile reinforcement of the liquefiable zone.
Table 3. The strength Geotextile material (after [30])
Trap Tear 4
[lb]
Puncture Strength 3
[lb]
Burst Strength 2
[psi]
Grab Strength 1
[lb]
Degree of Geotextile
Survivability
75
110
430
270
Very high
50
75
290
180
High
40
40
210
130
Moderate
30
30
145
90
Low
Note: The values are for minimum average roll (any roll must meet or exceed the minimum values as listed in
this table). These values are usually 20 % lower than typical values given by manufacturers. 1 ASTM D 4632,
2 ASTM D 3786, 3 ASTM D 4833, 4ASTM D 4533.
International Journal of GEOMATE, June, 2022, Vol.22, Issue 94, pp.102-112
111
Fig.17 The factor of safety value after using the geotextile reinforcement
Fig.18 The variation of the factor of safety values
during the earthquake shaking after using the
geotextile reinforcement
4. CONCLUSION
The static and dynamic stability of Al-Adhaim
Dam was evaluated by using SLOPE/W and
SEEPE/W. The values of seepage, pore water
pressure, and factor of safety were determined for
the static condition. The dynamic stability was also
evaluated during the earthquake shaking by using
QUAKE/W. The following conclusions can be
drawn from the analysis:
• The values of seepage and pore water pressure
were within the allowable limits before applying
the earthquake shaking.
• For the static condition, the values of the factor
of safety for the front face, the back face, and
the front face during the rapid drawdown were
1.882, 1.848, and 1.834, respectively. These
values were less than the allowable values that
are presented by the design guidelines of
USACE 2003.
• Applying ground shaking to the dam produced a
vertical displacement of 0.12 m and a relative
displacement of 0.4 m after 9 seconds of the
earthquake shaking.
• The minimum value of the dynamic safety
factor was 1.01 at T of 10 seconds which was
less than the allowable value (1.2) for the
dynamic stability.
• The relationship between the factor of safety
and the acceleration showed that the factor of
safety decreased to less than the allowable value
at a ground acceleration value of 0.12g.
• The liquefaction analysis indicated that the front
shell of the dam is liquefiable.
• Using geotextile reinforcement within the front
shell of the dam increased the factor of safety to
1.946 which was within the allowable values.
5. ACKNOWLEDGMENTS
The authors acknowledge the financial support
provided by the Lulea University of Technology
(LTU), Sweden. The authors also acknowledge
providing the data of the Al-Adhaim by the
Ministry of Water Resources (MOWR), Iraq.
6. REFERENCES
[1] Bishop AW. The Use of the Slip Circle in the
Stability Analysis of Slopes. Géotechnique
1955; 5: 7–17.
[2] Low BK, Gilbert RB, Wright SG. Slope
Reliability Analysis Using Generalized
Method of Slices. J Geotech Geoenviron Eng
1998; 124: 350–362.
[3] Cheng YM, Lau CK. A Study on Factor of
Safety Evaluation in Slope Stability Analysis.
HKIE Trans 2001; 8: 28–34.
[4] Zheng H, Tham LG, Liu D. On Two
Definitions of the Factor of Safety Commonly
Used in the Finite Element Slope Stability
International Journal of GEOMATE, June, 2022, Vol.22, Issue 94, pp.102-112
112
Analysis. Comput Geotech 2006; 33: 188–195.
[5] Salih AG. Influence of Clay Contents on
Drained Shear Strength Parameters of
Residual Soil For Slope Stability Evaluation.
Int J Geomate 2019; 17: 166–172.
[6] Newmark NM. Effects of Earthquakes on
Dams and Embankments. Géotechnique 1965;
15: 139–160.
[7] Ready B. Analysis of Slope Stability in Soft
Soil Using Hardening Soil Modeling and
Strengthening of Bamboo Mattress. Int J
Geomate 2020; 19: 226–234.
[8] Zhao Y., Mahmood N., Coffman RA. Soil
Fabric And Anisotropy as Observed Using
Bender Elements During Consolidation. Int J
of Geomechanics 2020; 20: 1–13.
[9] Hack R, Alkema D, Kruse GAM, et al.
Influence of Earthquakes on the Stability of
Slopes. Eng Geol 2007; 91: 4–15.
[20] Ausilio E, Conte E, Dente G. Seismic Stability
Analysis of Reinforced Slopes. Soil Dyn
Earthq Eng 2000; 19: 159–172.
[11] Zhang Z, Chang C, Zhao Z. Influence of the
Slope Shape on Seismic Stability of a Slope.
Adv Civ Eng 2020; 2020: 1–8.
[12] Seed HB. Considerations in the Earthquake-
Resistant Design of Earth and Rockfill Dams.
Géotechnique 1979; 29: 215–263.
[13] Gazetas G. Seismic Response of Earth Dams:
Some Recent Developments. Soil Dyn Earthq
Eng 1987; 6: 2–47.
[14] Artykbaev D. Stability Analysis of Fine Soils
from a Road Project, M32 Samara - Shymkent
(Russia - Kazakhstan). Int J Geomate 2020;
19: 205–212.
[15] Sawada Y, Nakazawa H, Oda T. Seismic
Performance of Small Earth Dams with
Sloping Core Zones and Geosynthetic Clay
Liners Using Full-Scale Shaking Table Tests.
Soils Found 2018; 58: 519–533.
[16] Ozkan MY. A Review of Considerations on
Seismic Safety of Embankments and Earth
and Rock-Fill Dams. Soil Dyn Earthq Eng
1998; 17: 439–458.
[17] Li Z, Wei J, Yang J. Stability Calculation
Method of Slope Reinforced by Prestressed
Anchor in Process of Excavation. Sci World J
2014; 2014: 1–7.
[18] Alrammahi F, Khassaf S, Abbas S, et al. Study
The Slope Stability of Earthen Dam Using
Dimensional Analysis Techniques. Int J
Geomate; 21. Epub ahead of print 1 July 2021.
DOI: 10.21660/2021.83.j2094.
[19] Purwanto P. Angle of Slope And Slope Safety
Factor Relationship in Gendol River, Southern
Slope of Merapi Volcano, Yogyakarta. Int J
Geomate 2019; 17: 93–99.
[20] Sulaiman SO, Najm ABA, Kamel AH, et al.
Evaluate the Optimal Future Demand of Water
Consumption in Al-Anbar Province in the
West of Iraq. Int J Sustain Dev Plan 2021; 16:
457–462.
[21] Forcellini D, Tarantino AM. Countermeasures
Assessment of Liquefaction-Induced Lateral
Deformation in a Slope Ground System. J Eng
2013; 2013: 1–9.
[22] Idriss IM, Boulanger RW. Semi-empirical
Procedures for Evaluating Liquefaction
Potentia. 11th Int Conf soil Dyn Earthq Eng
2004; 32–56.
[23] Lu L, Wang Z, Huang X, et al. Dynamic And
Static Combination Analysis Method of Slope
Stability Analysis During Earthquake. Math
Probl Eng; 2014. Epub ahead of print 2014.
[24] Sulaiman SO, Al-Ansari N, Shahadha A, et al.
Evaluation of Sediment Transport Empirical
Equations: Case Study of The Euphrates River
West Iraq. Arab J Geosci 2021; 14: 825.
[25] Mishal UR, Khayyun T. Stability Analysis of
an Earth Dam Using GEO-SLOPE Model
under Different Soil Conditions. Eng Technol
J; 36. Epub ahead of print 25 May 2018. DOI:
10.30684/etj.36.5A.8.
[26] Sulaiman SO, Kamel AH, Sayl KN, et al.
Water Resources Management and
Sustainability over the Western Desert of Iraq.
Environ Earth Sci 2019; 78: 495.
[27] Sulaiman SO, Al-Dulaimi G, Al Thamiry H.
Natural Rivers Longitudinal Dispersion
Coefficient Simulation Using Hybrid Soft
Computing Model. Proc - Int Conf Dev
eSystems Eng DeSE 2019; 2018-Septe: 280–
283.
[28] Noon AM, Ahmed HGI, Sulaiman SO.
Assessment of Water Demand in Al-Anbar
Province- Iraq. Environ Ecol Res 2021; 9: 64–
75.
[29] U.S. Army Corps of Engineers. Engineering
and Design, Slope Stability. Washington, DC
20314-1000,(2003).
[30] USACE. Engineering Use of Geotextiles.
Technical Manual, Air Force Manual, No. 32-
1030, Departments of the Army and the Air
Force, Washington, DC,(1995).
Copyright © Int. J. of GEOMATE All rights reserved,
including making
copies unless permission is obtained
from the copyright proprietors.
