Table of content

Journal of Engineering

مجلة الهندسة

ISSN: 17264073
Publisher: Baghdad University
Faculty: Engineering
Language: Arabic and English

This journal is Open Access

About

The Journal Engineering was issued in 1986. It was Stopped from 1990 – 1997 because of the economic blockade. It restarted publication after the fourth scientific engineering conference for it published the papers that were accepted in the conference.
It is a scientific engineering journal refereed by specialized and qualified professors in most of the engineering fields and those Specialists in the issued by the college of Engineering university of Baghdad .It was serenely publibued , but from 2011 it has issued of monthly for the numerous papers submitted to the journal to publish their papers in this scientific journal in addition to some of the Arabs professors because the journal is considered one of the valued journals in the Arabic homelan .
Many professions were the head editor of the journal from its first issue. The first one was prof.dr. Laith Ismail Namiq then prof.dr. Mohammed A.Alawis ,prof.dr.Ali A Al – kilidar prof.dr. Abdul-Ilah Younis and currently Prof.dr.Qais S. Ismail.

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Contact info

Jadriyah, Baghdad
Iraq
Mobile:
Email: joengbag@uobaghdad.edu.iq

Table of content: 2013 volume:19 issue:7

Article
Water Hammer Arresters; Review Studies and Practical Experiments for Alternatives
كوابح المطرقة المائية؛ الدراسات السابقة والتجارب العملية لايجاد البدائل

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Abstract

The current research deals with practical studies that explain to the Iraqi consumer multiple instances about the phenomenon of water hammer which occur in the water pipeline operating with pressure. It concern a practical study of the characteristics of this phenomenon and economically harmful to the consumer the same time. Multiple pipe fittings are used aimed to reduce this phenomenon and its work as alternatives to the manufactured arresters that used to avoid water hammer in the sanitary installations, while the consumer did not have any knowledge as to the non-traded for many reasons, including the water pressure decreases in the networks and the use of consumer pumps to draw water directly from the network. Study found a number of conclusions and recommendations of some of the most important pipe fittings have been effective in curbing this phenomenon, as reflected in the illustrations included in the search.


Article
Medical waste management in Al-Kut City
ادارة النفايات الطبية في مستشفيات مدينة الكوت

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Abstract

This research investigates solid waste management in Al-Kut City. It included the collection of medical and general solid waste generated in five hospitals different in their specialization and capacity through one week, starting from 03/02/2012. Samples were collected and analyzed periodically to find their generation rate, composition, and physical properties. Analysis results indicated that generation rate ranged between (0.12 – 2.5) kg / bed / day, moisture content and density were (19.0 % - 197 kg/ m3) respectively for medical waste and (41%-255 kg/ m3) respectively for general waste. Theoretically, medical solid waste generated in Al-Kut City (like any other city), affected by capacity, number of patients in a day, and hospital specialty The research exposed the incorrect ways used in collecting, storing, waste transport, and inefficient incinerators processing .Laboratory test for six ash collected samples indicated high concentration of heavy metals (Pb, Cd, Cr) , having the rang of (51.0 – 62.0) mg / l of lead, (3.0 – 8.5) mg / l for cadmium, and (43.0 -69.0) mg / l for chrome. In comparison with the US Environmental Protection Agency standards, these samples are higher than the recommended levels that may threat groundwater. A comprehensive and integrated solution there must be to manage medical waste, with the participation of all parties concerned, especially, the Ministry of Health, environment authorities concerned, and the participation of civil society organizations. A color-code trash bags and containers are recommended by the World Health Organization and the Environmental Protection Agency to be used in hospitals that propose red bags for collecting medical waste while black bags for general waste provided that they are resistant to tearing seeping and should be provided in sufficient numbers.


Article
Soil-Structure Interaction of Retaining Walls under Earthquake Loads
تداخل الجدران الساندة للمنشئات مع التربة تحت تأثير الهزات ألارضية

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Abstract

The study is devoted to both static and earthquake response analysis of retaining structures acted upon by lateral earth pressure. Two main approaches were implemented in the analysis, namely, the Mononobe-Okabe analytical method and the numerical Finite element procedure as provided in the ready software ABAQUS with explicit dynamic method. A basic case study considered in the present work is the bridge approach retaining walls as a part of AL-Jadiriya bridge intersection to obtain the effects of the backfill and the ground water on the retaining wall response including displacement of the retaining structure in addition to the behavior of the fill material. Parametric studies were carried out to evaluate the effects of several factors such as vertical and horizontal components of the earthquake, maximum peak acceleration, angle of friction, damping ratio, height of the wall and groundwater level within the medium of fill. Three heights of retaining walls were considered for those above mentioned factors, these are (2.9m, 4.7m and6.7m). A comparison is made between the responses obtained on the basis of finite element analysis with those obtained using the Mononobe-Okabe method. It is found that the lateral wall responses obtained using the FE were larger than those calculated by the Mononobe-Okabe method for all heights of the retaining wall, it was also found that pore pressure of the ground water depends on the water flow through the backfill during the earthquake. The distribution of the dynamic earth pressure on the wall is nonlinear and depends on the earthquake ground acceleration in addition to the wall height and soil properties. Based on the numerical analysis and the results obtained from the parametric studies carried out, two expressions are proposed to evaluate the maximum lateral wall response in terms of wall height, soil properties and earthquake base excitation acceleration, and hence the dynamic earth pressure acting on the retaining structure.


Article
Numerical Simulation of Temperatures Distribution and Residual Stresses of High Melting Temperature Polymer
نمذجه عدديه لتوزيع درجات الحرارة والإجهادات المتبقية في اللدائن ذات درجات الانصهار العالية

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Abstract

This work predicts the effect of thermal load distribution in polymer melt inside a mold and a die during injection and extrusion processes respectively on the structure properties of final product. Transient thermal and structure models of solidification process for polycarbonate polymer melt in a steel mold and die are studied in this research. Thermal solution obtained according to solidify the melt from 300 to 30 and Biot number of 16 and 112 respectively for the mold and from 300 to 30 and Biot number of 16 for die. Thermal conductivity, and shear and Young Modulus of polycarbonate are temperature depending. Bonded contact between the polycarbonate and the steel surfaces is suggested to transfer the thermal load. The temperatures distribution produces in thermal model importing as load and boundary conditions to solve the structure model. 3D mold and die are built to simulate the thermal and structure behavior using ANSYS 12.1 program. The results show that the temperatures and residual stresses decreases with the distance from the center to surfaces for the mold ,while for the die the temperatures and stresses decreases with the distance from the inlet to the outlet. The temperatures and stresses decreases with the time increasing for both mold and die. Also the thermal strain compatible with the temperatures distribution in the mold and the die. The total deformation concentrated at the left and right edge of polycarbonate in the mold, while starting in the center of the polymer at the outlet and then transfer to the entry of the die with the time increasing.


Article
Behavior of Reinforced Gypseous Soil Embankment Model under Cyclic Loading
تصرف التربة الجبسية المسلحة في التعلية الترابية تحت تأثير الاحمال الدورية

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Abstract

The construction of embankment for roadway interchange system at urban area is restricted due to the large geometry requirements, since the value of land required for such construction is high, and the area available is limited as compared to rural area. One of the optimum solutions to such problem is the earth reinforcement technique which requires a limited area for embankment construction. Gypseous soil from Al-Anbar governorate area was obtained and subjected to various physical and chemical analysis to determine it is properties. A laboratory model box of 50x50x25 cm was used as a representative embankment; soil has been compacted in five layers at maximum dry density (modified compaction) and an aluminum reinforcement strips were introduced between layers. The model was subjected to cyclic loading and the vertical and lateral deformations were detected at different stages of loading cycles using LVDT. The reinforced soil embankment under soaking condition exhibited vertical settlement at the top surface was (12.55 mm) while the lateral displacements at (1st, 3rd layer) were (2.18, 1.32) mm respectively at (47 load cycles).For reinforced gypseous soil, embankment without soaking cured for 24 hours, the Number of load cycles was found to be (165) loading cycles with vertical displacement (9.12 mm), that means an improvement of 59%. Accordingly, the lateral displacement in 1st and 3rd layers were (3.28, 2.59) mm respectively which observes improvement by (28% and 5%) respectively. The rates of improvement are taken with respect to the reinforced pure dry soil sample.


Article
Retrofitting Reinforced Concrete One–Way Damaged Slabs Exposed to High Temperature
اعادة تاهيل البلاطات باتجاه واحد الخرسانية المسلحة المتضررة المعرضة الى درجات حرارية عالية

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Abstract

Exposure of reinforced concrete buildings to an accidental fire may result in cracking and loss in the bearing capacity of their major components, columns, beams, and slabs. It is a challenge for structural engineers to develop efficient retrofitting techniques that enable RC slabs to restore their structural integrity, after being exposed to intense fires for a long period of time. Experimental investigation was carried out on twenty one slab specimens made of self compacting concrete, eighteen of them are retrofitted with CFRP sheets after burning and loading till failure while three of them (which represent control specimens) are retrofitted with CFRP sheet after loading till failure without burning. All slabs had been tested in a simply supported span and subjected to two-point loading. The main variables were the effect of different temperature levels (300ºC, 500ºC and 700ºC), different concrete compressive strength (20MPa, 30MPa and 40MPa) and cooling rate (gradually and sudden cooling conditions) on the behavior of retrofitted one way slabs .The structural response of each slab specimen was investigated in terms of load-deflection behavior, ultimate load carrying capacity and mode of failure. The experimental results, generally, indicate that slabs retrofitted using CFRP sheets restored flexural strength values nearly equal to or lower than those of the reference slabs, the retrofitted slabs exhibited larger deflection than the control slabs at ultimate loads. Retrofitted control slabs after loading regained about 93.95% to 97.92% of their original load capacity (before retrofitting) while the other slabs regained from 42.% to 84% of the load capacity of the original control specimens. Most of the tested slabs failed by concrete crushing at mid span and partial debonding of certain retrofitting systems was also observed for a few cases.


Article
Detection and Removal of Polycyclic Aromatic Hydrocarbon from Selected Areas in Tigris River in Baghdad City
التحري عن المركبات الهيدروكاربونية العطرية وازالتها من مناطق مختارة في نهر دجلة في مدينة بغداد

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Abstract

Aromatic hydrocarbons present in Iraqi national surface water were believed to be raised principally from combustion of various petroleum products, industrial processes and transport output and their precipitation on surface water. Polycyclic aromatic hydrocarbons (PAHs) were included in the priority pollutant list due to their toxic and carcinogenic nature. The concern about water contamination and the consequent human exposure have encouraged the development of new methods for PAHs detection and removal. PAHs, the real contaminants of petroleum matter, were detected in selected sites along Tigris River within Baghdad City in summer and winter time, using Shimadzu high performance liquid chromatography (HPLC) system. Analysis of samples from selected sites proved that the most abundant component of aromatic hydrocarbons were phenanthrene naphthalene, and acenaphthylene, followed by fluorene, acenaphthene, fluoranthene, benzo (a) pyrene, anthracene. and pyrene were present in low concentrations ranging in a descending order. Chrysene and benzo (a) anthracene were found in very low concentration. A laboratory unit was designed to optimize the factors which may influence the feasibility of degradation processes of naphthalene and phenanthrene in aqueous matrices by oxidation with Fenton reagent. The study proved that 83% and 79% removal of naphthalene and phenanthrene were achieved applying optimum conditions of pH=3, temperature=40 ° C, H2O2=50 ppm and Fe2+ catalyst = 6 ppm.


Article
Improvement of Soil by Using Polymer Fiber Materials Underneath Square Footing
تحسين سلوك التربة بأستخدام الالياف البوليميرية تحت الاسس المربعة

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Abstract

The change in project cost, or cost growth, occurs from many factors, some of which are related to soil problem conditions that may occurs during construction and/or during site investigation period. This paper described a new soil improvement method with a minimum cost solution by using polymer fiber materials having a length of (3 cm) in both directions and (2.5 mm) in thickness, distributed in uniform medium dense sandy soil at different depths (B, 1.5B and 2B) below the footings. Three square footings has been used (5 ,7.5 and 10 cm) to carry the above investigation by using lever arm loading system design for such purposes. These fibers were distributed from depth of (0.1B) below the footing base down to the investigated depth. It was found that the initial vertical settlement of footing was highly affected in the early stage of loading due to complex Soil-Fiber Mixture (SFM) below the footing. The failure load value for proposed model in any case of loading increased compared with the un-reinforced soil by increasing the depth of improving below the footing. The Bearing Capacity Ratio (BCR) for soil-fiber mixture has been increased by ratio of (1.4 to 2.5), (1.7 to 4.9), and (1.8 to 8) for footings (5, 7.5, and 10 cm) respectively. The yield load-settlement for soil-fiber mixture system started at settlement of about 1.1% B while the yield load in un-reinforced soil started at smaller percentage which reflects the benefits of using such fiber materialfor improving soil behavior. Comparison between experimental and predicted (calculated) settlement below the footings showed the difference in ranges were within accepted limits for foundation settlements design.


Article
Theoretical Study of the Effect of Permeability Tensor upon Drainage of Soils
دراسة نظرية في أثر الكميات الممتدة للنفاذية في بزل الترب

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Abstract

the influence of permeability tensor upon drainage of anisotropic soils under ponded water and steady recharge (rainfall) is theoretically investigated. Tensorial permeability has led to the formulation of mixed type partial differential equations. Since there is no analytical solution to this problem, the formulation is therefore solved numerically by the method of finite elements. The finite element formulation is implemented into a computer model which can be applied to any problem of seepage under steady state conditions. Two different example problems representing two different flow conditions under full anisotropy have been studied. Results of the model for the isotropic case were checked against exact mathematical solutions derived analytically for isotropic soils and found to be accurate which indicates that using this model for anisotropic soils is safe and sound.


Article
Effect of Swelling Soil on Load Carrying Capacity of a Single Pile
تأثير الترب اللأنتفاخيه على قابليه تحمل الركيزه

Authors: Ala Nasir Aljorany --- Fatema Safaa Noori
Pages: 896-905
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Abstract

Expansive soils are recognized by their swelling potential upon wetting due to the existence of some clay minerals such as montmorillonite. An effective solution was found to avoid the danger of such soils by using piles. A single pile embedded in an elasto-plastic expansive soil has been analyzed by using one of the available software which is ABAQUS to investigate the effect of applied loads on pile’s top and investigate the effect of swelling soils on load carrying capacity of the pile. The result shows that as the pile is axially loaded at its top, the axial force along the pile gradually changes from (tension) to (compression) and the pile tends to move downward. The applied load needed to initiate pile’s settlement depends on pile’s embedment depth and the depth of active zone. The ultimate carrying capacity of a single pile for no swelling conditions is greater than that of with swelling conditions.


Article
Effect of Design Parameters and Support Conditions on Natural Frequency of Pipe Excited by a Turbulent Internal Flow
دراسة تأثيرالمتغيرات التصميمية وشروط الأسناد على التردد الطبيعي لأنبوب يثار بجريان داخلي اضطرابي

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Abstract

In this study, the effect of design parameters such as pipe diameter, pipe wall thickness, pipe material and the effect of fluid velocity on the natural frequency of fluid-structure interaction in straight pipe conveying fully developed turbulent flow were investigate numerically, analytically and experimentally. Also the effect of support conditions, simply-simply and clamped-clamped was investigated. Experimentally, pipe vibrations were characterized by accelerometer mounted on the pipe wall. The natural frequencies of vibration were analyzed by using Fast Fourier Transformer (FFT). Five test sections of two different pipe diameters of 76.2 mm and 50.8 mm with two pipe thicknesses of 3.7 mm and 2.4 mm and two pipe materials, stainless steel and polyvinyl chloride PVC in the range of Reynolds numbers from 4*104 to 5*105 were studied. Mathematically, the governing continuity and momentum equations were solved numerically by using the finite volume method to compute the characteristics of two dimensional turbulent flow. The dynamics of a pipe conveying fluid was described by the Transfer Matrix Method (TMM) which is provides a numerical technique for solving the equations of pipe vibrations for simply-simply and clamped supports. The results showed that, the natural frequencies increase with pipe diameter increase and the natural frequencies slightly increases with pipe wall thickness increase. Also, the natural frequencies in clamped-clamped supported pipe are higher than those in simply-simply supported pipe.

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