Journal of Environmental Treatment Techniques 2015, Volume 3, Issue 2, Pages: 105-112
105
Geotechnical & Foundation Engineering Studies of Additional
Structures of Ssaluyeh
Ghodratollah Mohammad
1
, Alireza Ashofteh
2
*
1- Exploration Department, Islamic Azad University, South Tehran branch, Tehran, Iran.
2- Exploration Department, Islamic Azad University, South Tehran branch, Tehran, Iran.
Received: 27/12/2014 Accepted: 16/06/2015 Published: 30/06/2015
Abstract
This article is for presenting the final results of soil investigation and geotechnical studies at the site of Asaluyeh of Bushehr.
For studies of Asaluyeh project, 4 boreholes and 4 test pits are bored or excavated in offshore and onshore facilities location. This
article presents the results of the geotechnical investigation for offshore facilities area consisting 4 boreholes. This article
contains the results of in-situ and laboratory geotechnical investigations and foundation engineering analyses. The site geological
aspects; physical and geotechnical characteristics and geotechnical parameters of soil layers; allowable soil bearing capacity of
various foundation types; settlement considerations and soil lateral pressures are evaluated.
Key words: Geotechnical, Asaluyeh, Bushehr, foundation
1 Introduction
1
The project site is located at southern Iran, 17km far
from Bushehr Port. Figure (1) shows the location of the
project site within the Iran's roads map. Also the satellite
view of the site is shown in Figure(2). The geotechnical
studies have been performed to recognize the properties of
subsurface soil layers and to assess the geotechnical
parameters which are to be used in foundation allowable
bearing capacity calculations. The main aims of these
studies are as follows:
1. Study the stratification, and determination of
thickness of the underlying strata.
2. Evaluation of the ground water table level.
3. Evaluation of geotechnical and chemical
properties of subsurface layers.
4. Calculation of bearing capacity and allowable
strength of shallow and deep foundations.
5. Assessment of the subgrade reaction modulus.
6. Assessment of lateral earth pressure coefficients.
7. Assessment of the allowed excavation slope.
2 Investigation Procedures
In order to achieve the project objectives, total number
of four 35m deep boreholes(BH-1 to BH-4) has been
drilled. All boreholes were drilled with continuous coring
method. The Standard Penetration Tests(SPT) has been
performed in the boreholes during the drilling processes.
Grain size distribution, Hydrometry, Atterberg limits,
Specific gravity, Triaxial(UU and CU), Chemical analyses,
Corresponding author: Alireza Ashofteh, Exploration
Department, Islamic Azad University, South Tehran
branch, Tehran, Iran.
and Permeability tests have been performed on samples.
Figure 1. Geographical vicinity of the project site
Figure 2. The site location on the satellite picture of the area
Journal web link: http://www.jett.dormaj.com
J. Environ. Treat. Tech.
ISSN: 2309-1185
Journal of Environmental Treatment Techniques 2015, Volume 3, Issue 2, Pages: 105-112
106
3 Geology of the Project Area
According to geological zonation of Iran (Nabavi,
1976), shown in Figure (3), project area is located in folded
Zagros zone. The Zagros fold-thrust belt is a part of the
Alpine-Himalayan system that is considered as the result of
collision between the continental Arabian plate.
Figure 3: Geological zoning of Iran (Nabavi, 1976)
Location of the area is shown in Figure (4). The
properties of important formations are presented as follows:
Asmari formation: The oligocene–miocene asmari
formation of the Zagros basin is a thick sequence of
shallow water carbonate. The asmari formation represents
sedimentation on a carbonate ramp. In the inner ramp, the
most abundant lithofacies are medium grained wackestone–
packstone with imperforated foraminifera. The middle
ramp is represented by packstone–grainstone to floatstone
with a diverse assemblage of larger foraminifera. The outer
ramp is dominated by argillaceous wackestone
characterized by planktonic foraminifera. Three third-order
depositional sequences are recognized from deepening and
shallowing trends in the depositional facies, changes in
cycle stacking patterns, and sequence boundary features.
Gachsaran formation: This formation is the very first
formation of Fars group which its lower boundary is
oligocene age whilst its upper boundary is the early
miocene age. Salt stone, Anhydrite, Marl and a trifle of
shales stand for the main units of this formation.
Mishan formation: From early miocene, the marin
environments extended which led to the deposition of this
formation. This formation includes grey marls and clayey
limes those rich of shells and fossils. This formation is
located between Gachsaran and Aghajari formations.
Aghajari formation: Aghajari formation is the oldest
sedimentary unit belonging to the mio-pliocene and
containing blends of red Marl, brown fine sandstone with
cross bedding, reddish brown Siltstone and occasional gray
marl layers. Thin layers of gypsum are seen in whole
formation. Hence it is not astonishing to see clay, marl and
siltstone layers with gypsum in undisturbed samples from
Aghajari formation.
Bakhtyari formation: This conglomeratic formation has
alluvium sediment features which are formed from the
erosion of heights. Bakhtyari formation includes
conglomerate(which are cemented by calcites and clay
cements), limy sand stones which are deposited on older
deposits.
Young sediments: The project site is covered by recent
sediments, those about 7m coarse grained materials in
depth, in type of clayey and silty gravels. Sand stone lenses
can be perceived within the above-mentioned deposits.
After the depth of 7m in depth the soil type changes into
silty sands.
Figure 4: The geological map of the area with the approximate site location
4 Structural Geology
In the area of 100km from the Plant area several
seismic faults that have caused some earthquakes in the
past are located. Moreover there are some minor faults that
are not important and can‟t cause earthquake.
1. Labe Kuhestan fault about 10km far from the
area
2. Borazjan fault about 33km far from the area
3. Nezam Abad fault about 52km far from the area
4. Karis fault about 58km far from the area
5. Labe Godal Zagros fault about 70km far from the
area
6. Ghir Fault about 84km far from the area
Figure 5: A view of drilling machine
Journal of Environmental Treatment Techniques 2015, Volume 3, Issue 2, Pages: 105-112
107
5 Drilling and sampling
Four 35m deep bore holes have been drilled. The co-
ordinates of boreholes are presented in the Table(1).
Drilling procedures have been performed using an OGB
drilling machine shown in Figure(5). Required samples
were taken during the drilling and sent to laboratory to
perform different physical and mechanical tests. Borehole
sheets have been prepared based on field observations
during drillings. The borehole logs and field and laboratory
test results are presented in the appendix. Likewise, some
photos of the samples are shown in appendix.
Table 1: Coordinates of boreholes
Borehol
e
Co-ordinates
Depth(
m)
G.
W.Depth(m)
X(m)
Y(m)
Z(m)
BH-1
510.6
2
1080.
90
105.2
7
35.0
3.6
BH-2
442.1
6
924.3
6
103.4
8
35.0
1.8
BH-3
521.8
2
862.9
6
103.2
5
35.0
0.8
BH-4
572.2
9
938.3
1
103.3
51
35.0
0.5
6 Subsurface Condition
According to the field and laboratory test results,
subsurface layer conditions are described as follows:
The surface layer consists of filling materials with a
thickness about 7m. After this layer silty sandy layers are
recognized with interval silty layers(with low plasticity)
between them. The ground water table is varies from 0.5 to
3.6m. Two geological sections from the site of project are
presented in Figure(6).
Figure 6: The geological section No.1
7 In-Situ Tests
Standard Penetration Test
The Standard Penetration Test(SPT) is one of the most
common in situ tests for determining the physical and
mechanical properties of soil layers. SPT tests were
performed in the boreholes during the drilling procedure
and the results are presented in the borehole logs. Standard
Penetration Test is performed based on ASTM D1586. The
sampler is driven to penetrate 150mm in three stages by
repeated blows of a 63.5kg hammer falling freely from a
height of 760mm. The number of required blows to reach
150mm penetration stands for Standard Penetration number
for each stage. Total number of required blows for the last
two penetration stages would stand for NSPT. Figure(7)
shows SPT number variation versus depth. The results
indicate that the SPT number of all subsurface layers
exceeds 50 except for only 4 points.
According to Terzaghi classification, these layers are
classified as dense to very dense.
Figure 7: Variations of SPT number versus depth
8 Laboratory Test Results
The specimens have been used for performing different
physical, chemical and mechanical tests. Detailed test
results are presented in appendix. Furthermore, a list of
performed laboratory tests is presented in Table(2). In this
section, the results of laboratory tests are presented and
conclusions are made to suggest geotechnical parameters
for different soil layers based on laboratory and field test
results and engineering judgments.
Table 2. Laboratory test standards
Standard No.
ASTM D 421-422
ASTM D 4318
ASTM D 2488-2487
ASTM D 854
ASTM D 2850(UU) D 4767(CU)
ASTM D 2166
ASTM D 3080
ASTM D2434
ASTM D5738
9 Grain size analysis, liquid and plastic
limits
Grain size of the soil particles and their weight
distribution are determined based on percent of total dry
0
4
8
12
16
20
24
28
32
36
0 10 20 30 40 50 60 70 80 90 100
N
SPT
Depth (m)
BH-1
BH-2
BH-3
BH-4
Journal of Environmental Treatment Techniques 2015, Volume 3, Issue 2, Pages: 105-112
108
weight. Two methods have been applied for determination
of grain size distributions which are as follows:
The distribution of particle sizes larger than 0.075mm
is determined by sieving, while the distribution of particle
sizes smaller than 0.075mm is determined by sedimentation
process, using hydrometer. Grain size analyses have been
done based on ASTM D-421 standard in which dried soil
samples are trembled in a shaker accompanying standard
sieves. The size of the sieves is decreased from top to
bottom. Then the remained soil on top of each sieve is
weighed. Sieve analyses results are usually defined based
on passed weight percent of each sieve. In hydrometry
test(ASTM D-422) the diameter of suspended particles are
calculated based on velocity difference of the settled soil
particles in water according to Stokes rule. A standard
aerometer(ASTM 152H) has been used for determination of
suspended particle density. Fine grained soil classification
has been performed by Atterberg limit tests. Water content
and fine minerals cause solid, semi-solid, plastic and liquid
states. The moisture content of transition from the plastic
state to the solid state is called plastic limit. The moisture
content of transition from the plastic state to the liquid state
is called liquid limit. Plasticity index of soil is defined as
the difference between liquid limit and plastic limit. For
determination of Liquid limit based on ASTM D-4318 soil
sample is put into a special instrument including a brass
cup and a hard rubber leg. The cup rises up to 10mm while
the handle is rotated and falls down suddenly. A groove is
then created in the middle of the soil putty in the cup by a
cutter. The liquid limit is the value of the water content for
which a standard v-shaped groove is closed after 25 drops.
For accurate determination of liquid limit water percent(the
counterpart value of 25 blows) at least 4 tests shall be done
in which the number of blows varies between 15 and 35.
Liquid limit is determined using number of blows versus
water content in semi-logarithmic diagram. Plastic limit is
defined based on ASTM D-4318 as the water content at
which the clay can just be rolled to threads of 3.2mm
diameter. The grain size distribution graphs are presented in
Figures(8) and (9). As it is seen, the subsurface layers are
generally classified as SM and ML. Plasticity index of the
layers is very low, so these layers can be considerate as non
plastic.
Figure 8: The grain size distribution graphs(SM)
10 Specific Gravity
Specific gravity of soil particles is the proportion of
solid specific weight to water specific weight based on
ASTM D-854. In this test the volume of pre-determined
amount of soil and the weight of the dried soil is measured.
The ratio of dried soil weight to the water weight(of
volume equal to the soil volume) stands for the specific
gravity of soil. Specific gravity of soil samples was
measured and the results are shown in Table(3). Results
revealed that the specific gravity amount varies between
2.59 and 2.68.
Figure 9: The grain size distribution graphs(ML)
Table 3: Specific gravity test results
Borehole
Depth(m)
Gs
BH-1
5.0-6.0
2.64
18.5-19.0
2.59
BH-2
7.0-7.5
2.66
23.0-23.5
2.62
BH-3
5.0-5.5
2.65
17.5-18.0
2.66
32.0-32.5
2.65
BH-4
3.0-3.5
2.65
13.0-13.5
2.61
32.0-32.5
2.68
11 Direct Shear Test
Shear strength of soil is an important parameter used
for calculating bearing capacity of foundations and piles,
lateral pressure on retaining walls, and also to assess the
stability of slopes. This test has been performed based on
ASTM D-3080 using a specimen of 1 inch(25.4mm) in
height. Applying shear stress during the attendance of
normal stress, failure occurs in specimen. Test results are
presented in Table(4).
Table 4: Direct shear test results
Borehole
Depth(m)
USCS
Classification
φ(deg.)
c(kg/cm2)
Shear
speed(mm/min)
BH-1
5.0-6.0
SM
33.2
0.07
Slow
14.5-15.0
SM
35.7
0.04
Slow
18.5-19.0
SM
32.4
0.09
Slow
25.5-26.0
SM
33.5
0.09
Slow
28.5-29.0
SM
35.9
0.04
Slow
BH-2
7.0-7.5
SM
32.5
0.09
Slow
16.5-17.0
SM
32.8
0.08
Slow
23.0-23.5
SM
32.8
0.07
Slow
28.5-29.0
ML
27.8
0.15
Fast
BH-3
5.0-5.5
SM
32.9
0.07
Slow
9.0-9.5
SM
33.3
0.09
Slow
17.5-18.0
ML
28.4
0.13
Fast
25.0-25.5
SM
35.4
0.04
Slow
BH-4
13.0-13.5
SM
32.2
0.09
Slow
12 Triaxial Tests
Triaxial compression tests have been performed based
on ASTM D-3282. This test is the most reliable test for
determining the shear parameters of soils. In
unconsolidated-undrained triaxial test(UU), the specimen
would not allow to be drained during consolidation and the
shear phases. In consolidated undrained(CU) method,
# 80
# 40
# 16
# 10
# 4
3/8
1/2
3/4
1-1/2
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2-1/2
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3/8
1/2
3/4
1-1/2
2
2-1/2
3
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1-1/2
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1-1/2
2
2-1/2
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3/8
1/2
3/4
1-1/2
2
2-1/2
3
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# 10
# 4
3/8
1/2
3/4
1-1/2
2
2-1/2
3
# 200# 200
# 100
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1
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1
# 200
# 100
# 60
# 20
1
0
10
20
30
40
50
60
70
80
90
100
0.001 0.01 0.1 1 10 100
Particle Size (mm)
Percentage Passing
# 80
# 40
# 16
# 10
# 4
3/8
1/2
3/4
1-1/2
2
2-1/2
3
# 80
# 40
# 16
# 10
# 4
3/8
1/2
3/4
1-1/2
2
2-1/2
3
# 80
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3/8
1/2
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1-1/2
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2-1/2
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1-1/2
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3/8
1/2
3/4
1-1/2
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# 40
# 16
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3/8
1/2
3/4
1-1/2
2
2-1/2
3
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# 40
# 16
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# 4
3/8
1/2
3/4
1-1/2
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2-1/2
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# 16
# 10
# 4
3/8
1/2
3/4
1-1/2
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2-1/2
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# 40
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3/8
1/2
3/4
1-1/2
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2-1/2
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3/8
1/2
3/4
1-1/2
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3/8
1/2
3/4
1-1/2
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2-1/2
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3/8
1/2
3/4
1-1/2
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2-1/2
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# 60
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1
# 200
# 100
# 60
# 20
1
0
10
20
30
40
50
60
70
80
90
100
0.001 0.01 0.1 1 10 100
Particle Size (mm)
Percentage Passing
Journal of Environmental Treatment Techniques 2015, Volume 3, Issue 2, Pages: 105-112
109
specimen is primarily consolidated to a given pressure and
after complete dissipation of the excess pore water
pressure(Uc); the axial load will be increased till reaching
failure. During the shear phase the drainage is not available,
which results in formation of excess pore water
pressure(Ud). Triaxial compression test results are
presented in Table(5).
Table 5: The results of the triaxial compression tests
Borehole
Depth(m)
USCS Classification
Type of test
c(kg/cm2)
φ(deg.)
BH-1
7.45-8.0
SM
CU
0.09
30.3
18.5-19.0
SM
UU
0.17
8.6
24.5-25.0
SM
CU
0.08
30.6
BH-2
13.0-13.5
SM
CU
0.10
29.8
BH-3
7.5-8.0
SM
UU
0.17
9.9
28.5-29.0
ML
UU
0.47
9.4
BH-4
6.0-6.5
SM
CU
0.07
30.0
13 Permeability Tests
Any soil mass contains of solid grains of various
dimensions and continuous pore spaces. Continuous pore
spaces let water flow from points of higher energy to points
of lower energy. Permeability is a characteristic of soil
which permits the leakage of liquids among the continuous
pore spaces. To perform the permeability test, the soil
specimen is put in a tube. The water flows inside the
specimen by means of a fixed pipe connected to the top of
the tube. The initial head variation is recorded at the
elapsed time of zero. The water flow within the specimen
continues till the secondary head variation in the elapsed
time of 't' is achieved. Ultimately, the flow rate and the
permeability coefficient will be assessed in accordance with
the available standards. The permeability test is
accomplished in laboratory by falling and constant head
methods in accordance with ASTM D-2434. The falling
head test is suitable for the fine grained soils of low
permeability. The results are indicated in Table(6).
Table 6. Permeability test results
Borehole
Depth(m)
γd(gr/cm3)
K(cm/s)
BH-1
7.45-8.0
1.68
1.08E-03
18.5-19.0
1.70
1.89E-03
BH-2
7.0-7.5
1.62
1.63E-03
23.0-23.5
1.73
1.25E-03
BH-3
7.5-8.0
1.68
1.41E-03
14 Soil Chemical Analyses
Chemical analysis has been performed on 8 specimens
and the results are presented in Table(7). Test results show
that sulphate amount varies between 0.29 and 2.79 percents
while chloride ion amount varies between 0.140 and 0.490
percents. According to the Iranian concrete code the soil
can be categorized in 'medium' to 'extra sever' class
regarding its total sulphate content. Moreover, the PH value
varies between 8.4 and 8.8. Regarding the high amounts of
chloride and sulphates in southern Iranian islands, due to
the obligations of Iranian concrete code, application of
cement type II and consideration of the particular
provisions of concrete for south costal regions(based on
Iranian concrete code) is necessary. Furthermore,
consideration of ACI concrete code provisions for similar
conditions is alternatively possible. In this case, Portland
cement or mixed Portland cement like the slag Portland
cement and mixed Portland cement with natural and
artificial pozzuolana can be applied.
Table 7. Chemical test results
PH
(%)SO
2
3
(%)Cl
-
Organic
material
Depth(m)
Borehole
8.7
2.79
0.350
0.34
5.0-6.0
BH - 1
8.4
0.29
0.190
0.54
18.5-19.0
8.6
0.74
0.490
0.34
7.0-7.5
BH - 2
8.5
0.44
0.210
0.28
13.0-13.5
8.8
0.44
0.360
0.27
14.3-15
BH - 3
8.4
0.37
0.140
0.34
30.0-30.45
8.7
0.56
0.230
0.35
3.0-3.5
BH - 4
8.5
0.49
0.300
0.27
13.0-13.5
15 Chemical Analysis of Groundwater
Samples
The test results of chemical analyses on groundwater
samples obtained from boreholes are presented in Table 8.
Table 8: Chemical analysis results of groundwater samples
Borehole/Test
Pit
PH
)(ppmCl
)(
2
4
ppmSO
T.D.S(ppm)
BH - 1
7.8
21491.0
3090.0
54020.0
BH - 2
7.6
21381.0
3152.0
45280.0
BH - 3
7.6
21491.0
3123.0
43740.0
BH - 4
7.6
21824.0
3145.0
43850.0
16 Geotechnical Parameteres of
Subsurface Geological Layers
The section includes the evaluation of the geotechnical
parameters of subsurface layers. As said before, the surface
soil layer includes a 7.0m filling material. After this layer, a
sandy layer is recognized with SPT values more than 50.
Based on laboratory and in-situ test results, our engineering
judgment, and local experiences from the nearby project
sites; the properties of each layer are presented separately
in Table(9) and Table(10), respectively.
Table 9. Geotechnical parameters of surface layer(filling materials)
Cohesion
CCU = 0.05 ~ 0.1Kg/cm2
Internal friction angle
= 33 ~ 35deg
Natural density
gr/cm3 = 2 m
Poisson Ratio
= 0.32
Elastic modulus
E = 350 ~ 350kg/cm2
Table 10. Geotechnical parameters of sandy layers
Cohesion
CCU = 0.05-0.07Kg/cm2
Internal friction angle
= 26~28deg
Natural density
gr/cm3 = 1.85 m
Poisson Ratio
= 0.35
Elastic modulus
E = 250~300kg/cm2
17 Allowable Bearing Capacity of Shallow
Foundation
The allowable bearing capacity of shallow footings with
consideration of soil shear strength values and
Journal of Environmental Treatment Techniques 2015, Volume 3, Issue 2, Pages: 105-112
110
consideration of the allowable settlements are evaluated for
strip footings with different values of L/B ratios.
18 Bearing Capacity of Shallow Footings
With due consideration to the bearing capacity
correlations and settlement consideration, the allowable
bearing capacity of footings are assessed, when the footing
is to be sat on filling material layer and the related graphs
are presented in Figures(10) to (12). The footing length to
width ratio for the square, rectangular and strip footings are
1, 2 and 5 respectively. The graphs are presented on the
basis of single foundation total settlement value of 2.54
centimeter.
Figure 10: Allowable bearing capacity of square footings (L/B=1)
Figure 11: Allowable bearing capacity of rectangle footings (L/B=2)
Determination of the embedded foundation depth of
single footings is important. The value of the net pressure
depends on the soil layer depth on the footing, in bearing
capacity analyses. Figure(13) shows the embedded depth of
single and strip footings. As shown, the value of embedded
depth is the sum of Dc and excess slab thickness(t
floor
).
19 Stability Analysis
Based on the present information, the stability analysis
is performed for the embankment of filling materials and
the result is shown in Figure(14). The safety factor of
stability is equal to 1.18.
Figure 12: Allowable bearing capacity of strip footings(L/B=5)
Figure 13. The embedded depth in bearing capacity calculations of single
and strip footings
Figure 14. The result of slope stability analysis
20 Settlement Analysis
The Settlement analysis is performed for the
embankment of filling materials and the result is shown in
figure(15). The total settlement is measured about 2cm.
21 Dynamic Case
The vertical response of a rigid circular foundation can
be assessed by means of a „concentrated mass-spring-dash
pot‟ system(if appropriate coefficients for the stiffness of
spring and dash pot are applied) and on the basis of theory
of elasticity. Following equation is applied for the purpose:
1
4
0
Gr
k
zd
Lismar and Richard (1966)
Allowable Bearing Capacity (Square footing)
L/B=1 , Allowable settlement: 2.54 cm
0.6
0.8
1
1.2
1.4
1.6
1.8
0.5 1.0 1.5 2.0 2.5 3.0 3.5
Foundation Width (m)
Allowable Bearing Capacity (kg/cm
2
)
Df=0.5m
Df=1.0m
Allowable Bearing Capacity (Rectangular Footing)
L/B=2 , Allowable settlement: 2.54 cm
0.4
0.6
0.8
1
1.2
1.4
1.6
0.5 1.0 1.5 2.0 2.5 3.0 3.5
Foundation Width (m)
Allowable Bearing Capacity (kg/cm
2
)
Df=0.5m
Df=1.0m
Allowable Bearing Capacity (Strip footing)
L/B=5 , Allowable settlement:2.54 cm
0.4
0.6
0.8
1
1.2
1.4
1.6
0.5 1.0 1.5 2.0 2.5 3.0 3.5
Foundation Width (m)
Allowable Bearing Capacity (kg/cm
2
)
Df=0.5m
Df=1.0m
Journal of Environmental Treatment Techniques 2015, Volume 3, Issue 2, Pages: 105-112
111
Figure 15: The result of settlement analysis
In which μ is the soil Poisson Ratio, G is the shear
modulus and r0 is the circular foundation radius with the
equivalent area. The value of G can be obtained from the
geo-seismic test results presented earlier. However, as the
seismic tests are accomplished with small strains, the soil
shear modulus for machinery foundation can be calculated
by the following equation:
)1(2
E
G
As an example, by considering the value of 350Kg/cm2
for the elastic modulus and the value of 0.32 for the
Poisson Ratio; the shear modulus will be equal to
133Kg/cm2. By assuming the circular foundation
equivalent radius of 1m, the dynamic subgrade vertical
modulus will be 77900kg/cm.
22 The Friction Angle Between the
Concrete and the Material
After the recommendations of Bowels about the
concrete walls in case of smooth steel frame application;
the friction angle between the filling material soil and the
concrete will be . There fore its value can be
considerate from 22 to 25 deg.
23 Conclusion and Recommendations
The most important results and suggestions are as
follows:
1-According to the field and laboratory test results,
subsurface layer conditions are described as follows: The
surface layer consists of filling materials with a thickness
about 7m. After this layer silty sandy layers are recognized
with interval layers of silt between them.
2-The groundwater level of boreholes varies from 0.5 to
3.6m.
3-With respect to the geotechnical properties of the
subsurface layers, the allowable bearing capacities of single
footings(square, strip) have been calculated.
4-With respect to the soil types and the high strength of the
surface layers, no collapse or liquefaction problems are
probable.
5-With respect to the local weather conditions and the
index frostiness, the freezing depth can be neglected. Thus
a minimum embedment depth of 1m is recommended for
the shallow footings.
6-Within the foundation construction period, the soil
beneath the foundation should be inspected and the quality
should be approved by a qualified inspector.
7-According to Iranian code of practice for seismic
resistant design of buildings, Standard No. 2800(3rd
edition), the seismic hazard of study area is moderate and
design base earthquake acceleration(less than 10%
probability occurrence at 50 years) of study area is 0.25g.
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Author Profile :
Dr.Mohammad Ghodratollah
Mohammad Was born in
Iran on 1967. He did his
Ph.D from Islamic Azad
University of Science and
Research of Tehran, Iran.
He is presently working as
assistant professor in Azad
University in Iran. His field
of interest is Sedimentology
and Sedimentary.
Eng. Alireza Ashofteh
Alireza was born in Iran
on January 1982. He
received the M.Sc degree in
mining engineering from the
Exploration Department, in
Azad University, South
Tehran branch, Tehran,
Iran. He is a member of
Young Researchers and
Elite Club, Science and
Research, Islamic Azad
University, Tehran, Iran