Engineering and Technology Journal

Al-Najaf is one of the important cities in Iraq due to its high spiritual and religious
reputation that attracts Moslems from different parts of the world to visit the holy
shrine of Al-Imam Ali (peace be upon him). The city of Al-Najaf and particularly Bahr
Al-Najaf area, is expecting a number of large scale construction activities, among these
development activities are the planning of a new tourist city called Sayf Thulfiqar city.
Sayf Thulfiqar city is planned to be the largest tourist city in Iraq. The area of the
proposed tourist city is about 63 hectares, consists of an artificial lake 1000m long
surrounded by twelve towers and a number of small dwellings. This lake is considered
as a big challenge in planning, construction, and sustainability. The challenging points
primarily are the sources of water required to fill the lake, infiltration characteristics of
the soil at site, weather conditions, etc.
The present paper focuses on investigating the rate of water infiltration through the
base and side walls of a pit with dimensions 3m by 3m and 0.5m in depth excavated
and filled with water in the location of artificial lake. The process of filling was
repeated several times with full observation and continuous field measurements. The
results revealed some useful characteristics and correlations regarding the infiltration
of water of artificial lake in Bahr Al-Najaf

Gypsies Soils are disturbed in many regions in the world including Iraq, which
cover about (30 %) of the surface area of the country (Al-Dulaimi, 2004). Existence of
these soils, sometimes with high gypsum content, caused difficult problems to the
buildings and strategic projects due to dissolution and leaching of gypsum by the
action of water flow through soil mass. In this research, a new technique is adopted to
investigate the performance of replacement and geosynthetic reinforcement materials
to improve the gypseous soils behavior through experimental set up manufactured
locally specially for this work. A series of tests including dry and wet tests were
carried out using steel container (600×600×500) mm. A square footing (100×100) mm
was placed at the center of the top surface of the bed soil. The results showed that the
most effective thickness for dune sand layer with geotextile at the interface, within the
tested range, was found to be almost equal to the width of foundation. Therefore, under
this depth, the soil was reinforced with geogrid and geotextile. The bearing capacity
increases to (1.5-2.0) time under concentric loads and (2.5-3.0) under eccentric loads
after replacement and reinforcement of gypseous soil.

In this paper investigation in the end bearing and shaft resistance of bored piles
embedded in medium sand and subjected to axial load for wide rang of stress levels
starting from laboratory dimensions and go toward field dimensions were made by
utilizing the finite element method. The soil is modeled using hyperbolic soil model with
empirical equation account for reduction of angle of internal friction Ø with increase in
stress level while the bored pile assumed as a linear elastic material. It was found that the
stress level has a significant effect on pile’s behavior and the small scale model in
laboratory dimension not represent the real behavior of pile in field dimensions and if the
results from such dimensions are adopted, it will lead to overestimate of bearing capacity
factor Nq. Also, the effect of embedment ratio (L/D) on pile’s behavior is examined in
this study and the results showed that the embedment ratio (L/D) increases the bearing
capacity

Transient response and vibrations of an elastic plate resting on sandy soil are
presented. Plates are commonly used structural elements and are subjected to wide
variety of static and dynamic loads. Such studies are of particular interest in analytical
investigations related to structural foundation on soil media. The influence of impact
induced high strain-rates within the structure, which causes property changes in all
used materials, has to be regarded according to experimental results.
The main objective of the present paper, using the finite element approach through
ANSYS program is the simulation of the dynamic response of the foundation under
impact load. As a case study, previous experimental work included application of a
dynamic load generated by dropping a steel ball (38.1 mm in diameter, 2.22 N in
weight) from a height of 609.6 mm onto an aluminum target plate (203.2 mm in
diameter, 12.7 mm thick) placed on top of a sand medium. The impact load is defined
as a product of the loading magnitude and a time varying function which is assumed to
be a Hanning's function for a monopeak, smooth-shaped curve. The problem is
discretised by using four types of elements; Solid 45 to model the soil, Shell 63 to
model the aluminum plate and Target 170 and Contact 174 are used to model the
contact between the plate and soil. Shell 63 (elastic shell) has both bending and
membrane capabilities

Consolidation properties of clay soils are evaluated in the laboratory using the
one-dimensional consolidation test. The one-dimensional consolidation testing
procedure was first suggested by Terzaghi (1925). In this procedure, the load on
the specimen is applied and usually kept for 24 hours. After that, the load is
doubled. Therefore, the duration of this test may continue at least 1 week and this
duration is unpreferable for traditional purposes if the work is huge.
In this paper, decreasing of applied loading test time has been studied through a
new proposed time for applied loading. The results of a new time procedure have
been compared with standard (conventional) Oedometer tests that they have been
carried out on remolded samples of clay to investigate the difference percentage if
quick tests are adopted instead of long tests.
The comparison shows that the compression index increases with the increase
test time, therefore, the compression index must be modified (use 1.1 Cc) when
employed to calculate the settlement of soil. Also, the elapsed time of test is
significant to the determination of swelling index. So, the test time of applied load
should be not less than 2hrs.
The results show that two hours are enough to reach 90 % consolidation (t90).
The values of pre-consolidation pressure predicted depending

The present work is aimed to show the efficiency of 2-D Electrical Resistivity
Imaging (ERI) in probing the subsurface soil for site investigation, in addition to
highlight some capabilities and characteristics of the sections acquired by 2D-ERI
survey. In the field survey, where the University of Technology site is chosen for
such investigation, ERI technique has been used implementing three common
arrangements (Wenner, Wenner-Sclumberger and dipole-dipole). Different
resolving powers have been obtained for the used arrays. Wenner-Schlumberger
array gives moderate number of possible measurements and has a median depth of
investigation of about 10% larger than that for the Wenner array. It is moderately
sensitive to both horizontal and vertical structures, thus it might be a good
compromise between the Wenner and the dipole-dipole arrays. Good agreements
have been obtained between the stratigraphic columns of the site with the inversion
models using the different arrays. The distribution of resistivity of the inversion
models for the study site reflects the highly inhomogeneous subsurface soil with a
wide variation of soil resistivity at different depths

In this research, the conical shell foundation is investigated. The two components of
the interacting system; the soil and the shell foundation, are modelled using the finite
element method. In this study, 15-node isoparametric triangular axisymmetric elements
with two degrees of freedom at each node are used to model the shell and soil. The soilstructure
interaction between the footing and the supporting medium are modelled using
interface elements. Comparison between the results obtained by the present analysis and
those obtained by other investigations are made. The present analysis shows satisfactory
results when compared with those obtained by other studies with largest percentage
difference of 14% in the value of the ultimate load. Parametric studies have been carried
out to investigate the effect of some important parameters on the behaviour of shell
foundations. Three parameters are considered which are: semi-vertical angle, footing
embedment and edge beam

Construction of building and other civil engineering structures on weak or soft
soil is highly risky because such soil is susceptible to differential settlements, poor
shear strength, and high compressibility.Organic soils are difficult to deal with due
to their particular characteristics such as high compressibility and poor strength
and, as a consequence, criteria based on common mineral soils may not generally
be applied to them. The objective of this research is to investigate and assess
adding different percentages of organic matters on soil stiffness, from laboratory
experimental work, and to investigate the effectiveness of animal disposals and
plants pieces (leaves) ontwo soil types.
Hence, in the present research, mixed organic materials have been used, and it
was randomly included in to the soil at four different percentages of organic
content, i.e. 5, 10, 15, and 20% by the weight of two main raw, silty soil and clayey
soil. The research revealed from the laboratory tests that when organic
mattersincreased the stiffness of both clayey and silty soil were reduced, and the
reduction were from 16.5% to about 61

The effect of construction new tunnel on nearby tunnel was investigated using finite
element software program SIGMA/W. Two methods of excavation were used, one using
one stage in construction of tunnels and the other using eight stages of excavation. The
analysis also carried out to study the effect of nearby tunnel on existing tunnel by varying
the pillar width (W), using W equal to 3, 5, 7 and 12 m. The results show that, using
stages in construction of tunnel has no significant effect comparing with one stage. The
study indicates that there is significant effect of position of new tunnel on the existing
tunnel.

The lateritic soil that has high content of iron oxides and aluminum hydroxides
and low proportion of silica is widespread in the tropical and semi-tropical countries.
Lateritic soil as available materials in these areas utilized in different civil
engineering applications as roads, canals, earth dams, railways, building, … etc.
These applications are depending in a majority on soil classification in design the
construction on this soil type. One of the important parameters in classification of
soil is an Atterbage’s limits are used in definition of soil type and its strength. Due to
increase in population caused an increase in construction to demand the facilities of
this growth, therefore the desired soil decrease depend on used and the undesired soil
available. Soil stabilization utilized to improve the undesired soil properties by a
different technique to achieve the design requirement. Chemical stabilization
becomes one of the best solution to soil problems depend on economic and time save.
New chemical soil stabilization used is named (NBT II) in this study to exam the
effect on plasticity soil properties. Different percentages and different curing time
test conducted on lateritic soil to evaluate the range of effect and also examined the
effect of plasticity on dry density. The results show decrease in

This study implies a characterization and comparison between the historical
limestone and gypsum stones of Al-Namrud or (Calah) monument which
located in the north of Iraq 37 km to the eastern south of Mosul city (eastern
bank of the Tigris river) and those (fresh) extracted from Al-Mur hill which suppose
to be its quarry (according to the historicity and archeology references). The aim of
this study is the conviction of the veracity of these references depending on a number
of complementary engineering techniques. These tests include physicochemical and
mineralogical properties of fresh and historical stones , textural arrangement of
particles (porosity and pore size distribution) by mercury porosimetry tests; water
transfer properties by water retention curve test; bulk density at dry state by
hydrostatic weighing method have been executed . Also a comparison between the
fresh and historical stones has been carried out by X-Ray Diffraction (XRD) and
Thermo Gravimetric Analysis (TGA). Results shows for the historical stone higher
porosity and different pore size distribution, water transfer properties in comparison to
the fresh stone .Also, a high match in the compositions of stone materials of both
historical and fresh one reflect the rightness of the historicity and archeology
references and their consideration of being Al-Mur hill the quarry of Al-Namrud
monument.

The present paper is focused towards evaluation bearing capacity of subbase
layer which is contaminated with Kerosene.
Seven series of model tests were performed using steel container
(500*300*300mm). The bed of subbase was compacted in three layers inside the
container; each layer was 100mm in depth. Circular footing 65mm in diameter
resting on the bed of subbase were loaded incrementally up to failure. Different
percentages of Kerosene (0%, 5%, 12% and 20%) were added, the first series
consists of uncontaminated soil layer, the second series covers the model tests with
added (5%, 12% and 20%) to the top subbase layer and third series covers the
model tests with added (5%, 10% and 20%) to the top and second subbase layers.
Each percentage was added separately. The results showed increase in ultimate
bearing capacity; with increasing of Kerosene content up to 5% then a decrease
with further increase of Kerosene content

The paper gives a brief description of double wall cell triaxial equipment for testing
soil samples under unsaturated conditions and presents results of some of the
calibrations necessary to achieve accurate measurements of inner cell water volume,
pore water volume, pressure, load and displacement. The calibration of the
measurement devices showed linear relationships between the raw readings and
applied values with the regression constants differ from 1 and 0. The result of apparent
volume change calibrations showed significant correlation between cell water volume
fluctuation and temperature fluctuation inside testing room. A correction to the
measured volume was therefore required to reduce the effects of long-term temperature
fluctuation on the measured volume. Investigation of the accuracy of volume change
measurement with the double wall cell showed excellent matching between the inner
cell volume change and pore water volume change under saturated conditions,
indicating the high reliability of the double wall system for apparent volume change
measurements

In this paper, soil-water coupling analyses with finite element method are
conducted to investigate the long-term displacements of two-pile foundation installed
in saturated cohesive soils under different loading condition. As constitutive model for
clayey soil, elasto-plastic bounding surface model is considered, which is a
sophisticated elasto-plastic model for normally and over consolidated soils. The
influence of loading intensity and consolidation process are considered carefully. The
analyses showed that the elasto-plastic bounding surface model may provide a realistic
stress distribution within the soil mass around the piles. Also as conclusion of a series
of analyses, the followings are clarified; 1) the long-term behavior of two-pile group
system; 2) the mechanism of how the space between piles affects the long-term
displacements

Analysis of slope stability focus, on determining the value of the safety factor (Fs)
which is mean the ratio between the shear strength of the soil to the developed shear
stress on a certain slip surface. Engineers are interested with the minimum value of FS
which is obtained by analyzing some trials of slip surface. In the present work, slope of
two cohesive layers of the same unit weight is studying. About (100) different
problems are analyzed using the package (Slide 6.0). These problems takes into
account the impact of some factors on the minimum value of FS. These factors are: the
ratio between the cohesion of the top layer to that of the second one (cu1/cu2) which is
denoted by (Cr), the ratio between the height of the top layer to that of the slope (H1/H)
which is denoted by (Hr) and the angle of the slope (B). The results of the analysis are
normalized as a stability number (Ns).A regression analysis then conducted to these
problems using well known package (STATISTICA). The accuracy of the suggested
model is tested by R2. The value of R2 of model to predict stability number is about
0.982