Engineering and Technology Journal

ABSTRACT
Gypseous soils as any other soils deform under loading, this deformation differs
greatly between its dry state and its soaked state. This deformation also differs when
the loading is applied with eccentricity.
An experimental work was conducted on a square footing model (100 mm ´ 100
mm) above gypseous soil 450 mm thick. Loading was applied at the center of the
footing (e/B = 0) and at an eccentricity of (e/B = 0.05, 0.1, 0.15, 0.2) for its dry state
and its soaked state. Settlement was obtained at the center and at the base soil of the
footing for each state.
The data obtained was normalized and a proposed surface was obtained for each
of the two states (dry and soaked) and at two places (center and edge). Four proposed
equations were obtained represented four cases of research i) Dry center, ii) Dry edge,
iii) Soaked center, and iv) Soaked edge. The four equations showed very good
agreement with the data obtained from the experiment.
Artificial Neural Network model was also used to obtain a neural network
representing the proposed surface for the abovementioned four cases and also a very
good agreement was obtained.
It is concluded that a proposed surface for the central and eccentric loading on
square footing for gypseous soil showed a good agreement with the experimental data
and therefore may be used for settlement prediction

This research aims to assess some geotechnical properties and aquifer
parameters and consequently the applicability of predicting its properties from
surface electrical resistivity. The main output is to get several geotechnical
properties particularly those concerned with groundwater studies (such as porosity,
and permeability) and aquifer properties (such as resistivity, hydraulic conductivity
and transmissivity). To achieve this goal, interpretations of 50 Schlumberger VES
points distributed along 5 profiles, located in Salah Al-Din Governorate in central
Iraq, have been carried out. Sounding curve types obtained in the area are mostly
QQ and HK types. The application of VES technique has provided detailed
information on the thickness and hydrogeoelectrical characteristics of the aquifers
in the study area. Based on VES interpretation and their correlation with available
geotechnical data, four geoelectric layers were identified; these are topsoil,
unsaturated zone, saturated zone and the conductive layer. In addition, two aquifers
have been identified in the area under study. The upper is unconfined appeared
mainly in eastern side of Tigris River, whereas the lower is semiconfined-confined
appeared mainly in the western side of the River. Different target zones for
groundwater potential have been recognized on

The presence of organic matter in soil may cause different problems depending on
many factors such as type and contents of these organic materials. A testing program
was carried out to study the geotechnical properties and the behavior of organic
matter obtained by the addition of a sludge material brought from a sewerage
treatment plant.The tests include classification, chemical, compaction,
compressibility and shear strength tests. Based on the results, several conclusions
have been obtained. Both liquid and plastic limits increased with increasing organic
matter. Regarding compaction test, it can be noticed that both maximum dry density
and optimum moisture content slightly decreased with increasing organic contents
then tends to increase.Through the observation of shear strength test results, qu and cu
increased with increasing organic matter contents and then tends to decrease in
similar manner to the density water relation of compaction test. Regarding
compressibility, organic content, water content, void ratio and arrangement

Soils located above the groundwater table are generally unsaturated and exhibit
negative pore-water pressures. A soil-water characteristic curve (SWCC) that relates the
water content of a soil to matric suction is an important relationship for the unsaturated
soil mechanics. The SWCC essentially shows the ability of an unsaturated soil to retain
water under various matric suctions. The filter paper method is a soil suction
measurement technique. Soil suction is one of the most important parameters describing
the moisture condition of unsaturated soils. The measurement of soil suction is crucial for
applying the theories of the engineering behavior of unsaturated soils.
In this paper, three soil samples were collected from three sites within Baghdad city
in Iraq. These soils have different properties and they were prepared at different degrees
of saturation. For each sample, the total and matric suction were measured by the filter
paper method at different degrees of saturation. The soil samples were mixed with
different percentages of Nacl salt. It was concluded that the suction increases with
decrease of the degree of saturation. The relationships between the total and matric
suction and the filter paper water content are approximately linear and indicate decrease
of suction with increase of the filter paper water content. All soil samples exhibit unique
linear relationship between the total suction and filter

A field full scale flexible road is constructed and the effects of geotextile
reinforcement in paved road are tested by measuring the occurred rutting. The effect of
different numbers and positions of geotextile reinforcement using seven road sections are
evaluated and compared with unreinforced pavement section. It is found that a maximum
reduction of rut depth is 96% when using three reinforcement layers at three different
road layers interfaces, and a minimum reduction is 52% when using one reinforcement
layer at interface I ( between wearing and binder layers) under the effect of maximum
load cycles of 10000. The minimum Traffic Benefit Ratio (TBR= ratio between load
cycles on a reinforced section to that of unreinforced section for the same rut depth) is
found to be 4 when using one reinforcement layer in the interfaces I , and extremely large
values for other reinforcement cases. Once, the above values appear how the service life
of the paved road is increased by using geotextile reinforcement.
The cost-benefit analysis is also adopted in this research and found that by using one
reinforcement layer the road cost is increased by only 14% resulting in increment value
of TBR to 4 (this means that the road life is doubled 4 times if all other circumstances are
fixed). This is a minimum case benefit when comparing it with all other cases; it is found
that TBR values are exaggerated when different numbers and positions of geotextile
reinforcement layers are used.

In this paper the polypropylene fiber was chosen as the additive material to know
how it is effect on the soil stabilization, which it is used as additive for concret
mixture; the polypropylene fiber is inert material and does not interact with water. The
paper studies the addition of this material to a silty clay soil and its effect on the
consistency limits, shear strength and compaction of the blended materials. The results
show that there is an improvement in the shear strength only when the addition of the
rate 1% and 2%from soil weight; either the effective of the consistency limit it was
increasing the water content with increasing the rate of the addition material, because it
have drink of water. At the compaction test it was founded that the increasing in dry
density at the addition of 1% and 2% and reducing its value at the addition of 3% with
increasing of water optimization.

common minerals that found in soils. In Iraq, gypseous soils is a worldwide stability
problem that causes extensive damage upon wetting, and occur in certain areas
characterized by variation of climatic conditions. The results of the stability behavior
of lime stabilized gypseous soil where present in this paper under different tests. These
tests were erosion, leaching and soaking. Erosion test was conducted under different
variables such as water temperature, water velocity and flow duration. The soil used in
this study was taken from a site near Al – Hader district about (80 km) from Mosul
city. Its main geotechnical index properties are liquid limit is (46%), plastic limit
(22%) and specific gravity is 2.58. The amount of the gypsum was 20%. The soil
samples were treated with optimum lime percent (4%) depending on the Illinois
procedure. A gypseous soil with 20% gypsum content was used and stabilized with 4%
lime. All stabilized soil samples were cured for 2 days at 490 C. The results indicate
that, the loss in weight increased for samples subjected to the flowing water, further
increase in weight losses with increasing flow duration. High water velocity causes
increasing in weight losses and loss in gypsum

The unsaturated soils are difficult to consider within the framework of classical
(saturated) soil mechanics. In general, the unsaturated soil is stiffer than the saturated
one (hardening), so the location and slope of normal consolidated line (NCL) or the
volumetric yielding behavior of unsaturated soil is different from the saturated
behavior. This work investigates the volumetric yielding behavior of unsaturated soil;
by determine the One-dimensional normal consolidated lines (NCL’s) under different
suctions. Two materials namely pure Calcigel bentonite (100B) and a mixture of 30%
Calcigel bentonite and 70 % Haider sand (30B) were prepared at two initial conditions
(i.e. slurry and loose states). In this type of test, after reaching to the designed suction,
the net stress is increased through the test while the suction is kept constant. Thirteen
30B specimens and two 100B specimens were tested under constant suction condition.
The constant applied suction in this study was varied from 0 kPa till 39000 kPa
because of the possibility to increase the preconsolidation pressure (yield stress) more
than 24000 kPa (the maximum limit of the used one-dimensional high stress
consolidation equipments). Two techniques (i.e. axis translation technique and vapor
equilibrium technique) were used to apply and control suction on tests. The controlledsuction
one-dimensional high stress consolidation tests results

Total suction is the sum of the matric and the osmotic suction of the soil.
Various methods are used to measure the total suction of the soil. One of the
methods is the chilled–mirror hygrometer technique. The chilled-mirror device
employs a dew-point procedure, which is one of the most accurate and valuable
methods for measuring total suction in the mid- to high- total suction range.
The effect of the percentage of gypsum on the total suction estimation for a
gypsum-sand mixture has been investigated rarely in the past. In this paper,
the total suction is determined for soil specimens containing different
percentages of gypsum additive mixed with Silber sand. The soil specimens
were prepared at different initial conditions of density and degree of
saturation in order to investigate a wide range of physical soil properties. The
test results showed that an incremental increase in the percentage of gypsum and
degree of saturation of a soil mixture caused a reduction in the measured value of
total suction, while an increase in the initial dry density caused the measured
total suction to remain almost unchanged. No constant trend is observed with
respect to the effect of the curing time

A study was carried out to investigate the effects of recharging primary treated
domestic wastewater on soil characteristics by special recharge-recovery method
developed and practiced in the laboratory working model. Recently, the amounts of
wastewater are sharply increasing and the kinds of pollutants are also varied as the
world wide industry is being developed incessantly. The subbase soil is brought from
Jerashi quarry, northeast of Ramadi and placed in model which is made from plexus
glass with dimensions (1.1 m * 1.1 m * 0.6 m). Wastewater characteristics, main soil
and soil samples after recharging of wastewater 330L, 420L, 510L, and 600L, for one
time every seven days and comparing the means for soil chemical characteristics
before and after experiment. Soil reaction (pH), electrical conductivity (EC), organic
matter (OM), chloride ions (CL), sulphate content (SO3), gypsum content (GC), total
dissolved salt, (TSS), and total dissolved solids (TDS). The soil-aquifer system (SAT)
can be used efficiently as a wastewater treatment plant. After recharging wastewater,
there were slightly increase of pH and OM in comparison with EC, CL, SO3, GC, TSS,
and TDS which might cause problems in the long term if the land was used for
construction purposes

Piled raft foundations are a geotechnical composite construction consisting of three
elements: piles, raft and soil. In the design of piled rafts, the load is assumed to be
shared between the piles and the raft. Therefore, this may improve the ultimate load
capacity and reduce settlements in a very economic way as compared with the
traditional foundation concepts. Due to the development of structures that use piled
rafts as a foundation system, an extensive experimental study was performed by two
different scale models with the same L/Dp (Embedment length to pile diameter ratio)
and L/Br (Embedded length to raft width ratio Br) to achieve the scale effect and plane
stress condition for the large scale model and plane strain condition for the small scale
model. The load carrying capacity of the piles and raft have been studied and presented
as load-settlement illustrations. From a comparison between the two models of the
experimental work, it is found that the effect of scale cause an increase in carrying load
of piled raft with increasing the number of piles. It was found that the percentage of the
load carried by raft to the total applied load of the experimental model in the case of
four piles with raft is ranged between 60.6 - 64.8 %.

This investigational study was directed to establish the correlation between piled
raft foundation and two soil improvement techniques, stone columns and lime
columns to evaluate the bearing improvement ratio BCR for the soft clay soil with
three values of undrained shear strength, 8 kPa,10 kPa and 12 kPa. The 12 model
tests was conducted in the present work, three models of untreated soil, three models
of soil with piled raft, three models of soil treated with stone columns and three
models of soil treated with lime columns. The container used in experimental works
was made of steel with plane area of 500 mm * 500 mm and 500mm in height. The
thickness of soil sample inside the container was 400 mm.
The study showed that the piled raft was more efficient in the bearing capacity
improvement than the two soil improvement techniques. The bearing improvement
ratio were 3.39, 3.27 and 2.78 in the three model tests of piled-raft for three samples
of soil, respectively, while the lime columns provided the lowest values of the bearing
improvement ratio were 1.64, 1.67 and 1.8 respectively

Due to the higher increase in the oil industry activities in Iraq, since there are a
little information of the environmental status of the areas around the refinery
locations, and the concerns of a possible environmental pollution that will cause
health and life threats to living organisms, this study was carried out.To understand
the status of heavy metals pollution in areas inside and surrounding Al-Daura refinery
activities, (17) testing locations were chosen, ten locationsoutsidethe refinery and
sevenlocationsinside it.One additional location was chosen in a rural (control) area, in
the University of Baghdad, to compare between the heavy metals concentration in the
study area and a sample from the rural area not affected by the pollution. The soil
samples have been taken from (5 and 60 cm) depth from the top surface of the soil.
Three samples were taken from each depth for each location to take an average of
results.All the samples of soil were taken during the period from Dec/2010 to
Feb/2011.The experimental work has been includes the heavy metals concentrations,
such as Zinc, Nickel, Lead and Cadmium, have been measured at each selected depth
for each testing locations.The results indicate that the mean concentration of Zn and
Ni is (62.4 μg/g) and (100.5 μg/g) respectively

The purpose of this study is to investigate the behavior of skirted strip model
footing founded on beds of soft clays and to evaluate the improvement values in
bearing capacity. A series of laboratory model tests were conducted to determine the
optimal vertical capacities of skirted foundation within different skirted embedded
depth (D/B) ratio (embedded depth to footing width) ranged between (0.0-2.5). The
results of model tests based on the load-settlement behavior, revealed that the insertion
of skirt structure into the soft clayey soil has a clear increasing the magnitude of
bearing capacity with increasing (D/B) ratio according to the lateral confining pressure
as compared with the soft clay state without lateral confining (D/B = 0). As a principal
part in this study is to knowledge the adequate skirts embedment depth for
improvement the ultimate bearing capacity value. It is found that the appropriate
skirted embedded depth as the skirt depth to foundation width of 0.5 (D/B=0.5).

Dynamic compaction was considered as one of a deep compaction method which was
used to improve the soil properties. Also it was used to save cost and time in comparison
with other methods.
The aims of the present studies were to study the improvement and changes in soil
properties that occurred in Al-Mualla Site-Yeman using dynamic compaction. The site
soils classified as Silty Sand with small boulder with Clayey-Silt layer extend from 2.2 m
to 3.2 m deep.
Cone penetration test was done before and after treatment process using dynamic
compaction for approximately the same two tested boreholes. As a result of the treatment
and based on how the soil properties changes, the soil was divided into three zones varied
from (1.2 to 5, 5 to 8.6, and 8.6 to 11 m) respectively. Field results show that there was
increased in bearing capacity from 80 kN/m2 to 110 kN/m2. Cone penetration test for the
first zone increased from (1.2 to 8.35 MN/m2), and from (2.43 to 7.07 MN/m2) for the
first and third zone respectively at the first tested borehole and also from (2.05 to 6.8
MN/m2), and (2.14 to 5.0 MN/m2) for the second tested borehole. Also can be noted that
the cone penetration test results decreased from (5.22 to 3.77 MN/m2) for the second zone
at the first tested borehole, with no change was happening for the second tested
boreholes.
Also the effect of soil improvement on the settlement value and effective stress
distribution was studied theoretically using finite element package PLAXIS2D program.
The result shows that the improvement in soil properties leads to decrease in the expected
settlement.