Prof. Magdi Zumrawi | University of Khartoum (original) (raw)

Papers by Prof. Magdi Zumrawi

Zenodo (CERN European Organization for Nuclear Research), Sep 3, 2017

Determination of Resilient Modulus (M R) is quite important for characterizing materials in pavem... more Determination of Resilient Modulus (M R) is quite important for characterizing materials in pavement design and evaluation. The main focus of this study is to develop a correlation that predict the resilient modulus of subgrade soils from simple and easy measured soil index properties. To achieve this objective, three subgrade soils representing typical Khartoum soils were selected and tested in the laboratory for measuring resilient modulus. Other basic laboratory tests were conducted on the soils to determine their physical properties. Several soil samples were prepared and compacted at different moisture contents and dry densities and then tested using resilient modulus testing machine. Based on experimental results, linear relationship of M R with the consistency factor 'F c ' which is a combination of dry density, void ratio and consistency index had been developed. The results revealed that very good linear relationship found between the M R and the consistency factor with a coefficient of linearity (R 2) more than 0.9. The consistency factor could be used for the prediction of the M R of compacted subgrade soils with precise and reliable results.

University of Khartoum Engineering Journal, Oct 31, 2022

This paper presents an experimental study in stabilization of expansive soil using Steel Slag (SS... more This paper presents an experimental study in stabilization of expansive soil using Steel Slag (SS). Experimental program was conducted to evaluate the influence of Steel Slag on improving the engineering properties of expansive clay. A series of tests to measure consistency limits, free swell index, compaction parameters and unconfined compressive strength of natural and stabilized soils. The effectiveness of adding 0, 5, 10, 15, 20, and 30 percentages of SS to the soil was studied. Comparing the results obtained for the natural and stabilized soils, revealed that SS has significant effect on strength parameters and considerable improvement in plasticity and swelling properties. Addition of SS to the soil increased the dry density and decreased the optimum moisture content as well as increased the unconfined compressive strength. It is concluded that the use of steel slag to enhance properties of expansive soil is successful and beneficial.

University of Khartoum Engineering Journal, Aug 20, 2020

Khartoum airport plays a vital role in air traffic and national economy. The airport has experien... more Khartoum airport plays a vital role in air traffic and national economy. The airport has experienced poor performance and lack of services. Serious congestion, delay and cancellation problems in flights becoming a daily habits. The study aims to evaluate the existing airport facilities and services and their ability to meet future demand. The literature concerning airport capacity and performance related issues were reviewed. The research depend on documents information, site inspection, and interviews for evaluation. The historical data of travelers at the Airport were analysed to estimate the forecasted demand. The study has identified challenges facing the increasing travel demand in the airport. Facilities that are unable to accommodate the increase in travel demand were identified for improvement. Thus, the improvement has to be done by expansion of terminal building, extending apron area for more aircraft parking spaces, additional runway length, increasing taxiways width as well as optimizing the operational processes by introducing flexibility and using technology.

University of Khartoum Engineering Journal, Jun 12, 2017

University of Khartoum Engineering Journal, Apr 19, 2017

The study aims to investigate the effect of dewatering technique on retained ground and adjacent ... more The study aims to investigate the effect of dewatering technique on retained ground and adjacent existing structures in order to avoid any damages that may occur. The paper presents three cases of potential structure failure caused by ground settlement as a result of dewatering. Two current construction projects in Khartoum North were selected as a case study. The two projects are located near Blue Nile River where ground water table exists at shallow depths. Dewatering to reduce the groundwater level was carried out in the two sites to facilitate excavation works. The buildings and road pavements around the two sites suffered serious damages due to excessive differential settlements of the retained ground. The study results showed that there are numerous sources of risks associated with performing dewatering. Therefore, developing appropriate plan for dewatering before construction is essential to mitigate any adverse impacts and avoid risks.

This paper aims to identify the factors that cause damages to buildings constructed on expansive ... more This paper aims to identify the factors that cause damages to buildings constructed on expansive soils and suggests practical solutions to avoid swelling problems. Literature of buildings failures associated with expansive soils and techniques experienced to prevent the swelling damages were intensively reviewed. Three regions in Khartoum state, famous expansive soil areas were selected for this study. Ten cases of damaged buildings were randomly selected for investigation. A field survey of damages was conducted to diagnosis and point out the causes, extent and type of damage that was observed in the buildings. It was observed that eight lightweight buildings suffered heavy damages and only two other buildings were slightly damaged. Common failures observed were cracks in walls and floors, foundation movements, column buckling, sagging of beams and slabs in typical damage cases. It was found that poor surface drainage, gardens watering close to buildings, source of water leakage an...

This paper aims to assess the efficiency of using geogrid reinforcement for subgrade stabilizatio... more This paper aims to assess the efficiency of using geogrid reinforcement for subgrade stabilization. The literature of applying geogrid reinforcement technique for pavements built on soft subgrades and the previous experiences were reviewed. Laboratory tests were conducted on soil reinforced with geogrids in one or several layers. The soil specimens were compacted in four layers with or without geogrid sheets. The California Bearing Ratio (CBR) test, in soaking condition, was performed on natural soil and soil-geogrid specimens. The test results revealed that the CBR value is much affected by the geogrid sheet location and the number of sheets used in the soil specimen. When a geogrid sheet was placed at the 1<sup>st</sup> layer of the soil, there was an increment of 26% in the CBR value. Moreover, the CBR value was significantly increased by 62% when geogrid sheets were placed at all four layers. The high CBR value is attributed to interface friction and interlock involv...

The inconsistencies and variations in design of pavements arising from using different methods ha... more The inconsistencies and variations in design of pavements arising from using different methods has become a critical issue in Sudan. This paper is aimed to develop a structural design procedure for flexible pavements in order to simplify the design process by using a software program and provide a uniform structural design result. The literature of the conventional design methods commonly experienced in Sudan was intensively reviewed. In fact, these design methods were not designed to cater for the current needs and conditions of Sudan. Thus, an attempt was made to establish a simplified design procedure to accommodate the ever increasing traffic loads, available pavement materials and significant change in climate conditions in Sudan. Based on previous experiences, a design chart for a particular set of traffic loading and CBR values of subgrade soils and granular materials was developed. A software program using Visual Basic language of the Microsoft was created to facilitate the ...

University of Khartoum Engineering Journal, 2016

Shear strength of cohesive soils is great essential in determining the bearing capacity of founda... more Shear strength of cohesive soils is great essential in determining the bearing capacity of foundations, slope stability of embankments, and lateral earth pressures on retaining structures. This study mainly deals with the factors affecting the shear strength of compacted cohesive soils. A comprehensive literature review relevant to the shear strength characteristics and influencing factors was presented. Intensive laboratory investigation was undertaken on two clay soils selected from different regions in Khartoum state. Unconfined compression tests were performed on soil samples compacted at a wide range of moisture content and varied dry densities to measure the shear strength. The results reveal that the placement conditions (moisture content and dry density) and the soil intrinsic properties (plasticity and liquidity indices) have significant effects on the shear strength measured values. These parameters of simple and easy measured soil index properties were combined in a facto...

International Journal of Materials Science and Applications, 2017

The use of Crumb Rubber Modifiers (CRM) in flexible pavements to improve characteristics of aspha... more The use of Crumb Rubber Modifiers (CRM) in flexible pavements to improve characteristics of asphalt binders has become a technique of great potential in recent years. In this regard an experimental program was undertaken to study the influence of CRM on the physical properties of asphalt binder. Asphalt cement modified with varying percentages of CRM, 0, 5, 10, 15, 20, and 30 percent were studied. Penetration, ductility, viscosity, softening point, flash and fire points, and specific gravity tests were performed on base and modified asphalts. The tests results show that addition of CRM to base asphalt has significant influence on its properties. Comparing the tests results, the viscosity, softening point, flash and fire points of the modified asphalts increased significantly, coupled with reduction in penetration and ductility as the CRM content increased. Addition of 15% CRM resulted in 200% and 15% increment in viscosity and softening point of base asphalt respectively, while the ...

University of Khartoum Engineering Journal, 2017

This paper discusses the effect of Fly ash on the engineering properties of expansive soils. As r... more This paper discusses the effect of Fly ash on the engineering properties of expansive soils. As reviewed in literature, many previous investigations have shown promising results for improvement of expansive soil after stabilization with Fly ash. Laboratory tests have been conducted on expansive soils obtained from three different regions in Khartoum state. Various percentages of Fly ash such as 0%, 10%, 20%, 25%, and 30% by weight of soil were added to the three soils and their influence on the soil plasticity, swell characteristics and unconfined compression strength are discussed. Additions of Fly ash to the three soils resulted in significant improvement in the strength and reduction in plasticity and swell properties of soils. The unconfined compression strength of soils treated with 10% Fly ash showed almost 2 times improvement compared with untreated soils. For the addition of 10% fly ash, the reduction in free swell, swell pressure and swell potential is in the range 50% to 7...

University of Khartoum Engineering Journal, Jan 23, 2020

The success of a bridge relies on proper design and construction of its foundations. A Literature... more The success of a bridge relies on proper design and construction of its foundations. A Literature concerning water scouring at bridge foundation and some cases of bridge failure were intensively reviewed. Two global cases and a local case of foundation failure caused collapse of the bridge structure were selected for this study. The study was concentrated on Manshia Bridge in Khartoum. The investigation involved field survey and laboratory testing on this project to examine the existing foundation conditions. The eastern abutment investigated experienced sever failures in forms of excessive scouring and settlement in the embankment and the foundation piles surrounded by water. The causes of these failures were found mainly linked to the high scouring rate of water lead to washout the soil from the embankment of the abutment and the foundation piles. The foundation design mistakes, poor construction, inadequate abutment protection and lack of maintenance were detected as the main cause of the bridge failure. To protect abutment against scouring problem, it is recommended to use rock protection for the embankment and river bed around the abutment.

University of Khartoum Engineering Journal

Because of limited knowledge on experience on deep excavation analysis in Sudan, this study aimed... more Because of limited knowledge on experience on deep excavation analysis in Sudan, this study aimed to study numerical models for modeling deep excavation and adjacent buildings or public facilities near by the excavation. A series of parametric studies were conducted to evaluate the effect of wall stiffness and strut stiffness. The numerical analysis results showed that the increase of retaining wall stiffness or strut stiffness to reduce wall deformation is certainly effective, however does not have linear relationship. Last, based on the numerical results, the evaluation of adjacent building damage related to settlement induced by excavation and suggestions protection of adjacent buildings before and during excavation were discussed.

University of Khartoum Engineering Journal

This paper focuses on the influences of geotextile on bearing strength and permeability propertie... more This paper focuses on the influences of geotextile on bearing strength and permeability properties of cohesive soils. Experimental investigation was conducted on three soils reinforced with geotextile sheets in one or more layers. The soil samples are compacted at optimum moisture content and maximum dry density in five layers with or without geotextile sheets. The California Bearing Ratio (CBR) and the permeability tests have been carried out on natural soils and soils with geotextile sheets. The experiments results have showed a significant decrease in the CBR and the permeability values of the three soils with the inclusion of geotextile sheets. The CBR values of geotextile reinforced soils have decreased by 70% for 4 layers of geotextile sheets. Also, the average reduction in the permeability of the three soils reinforced with 1-layer geotextile sheet is about 60% of the natural soils. Hence, it is concluded that provision of geotextile sheet with an activator such as lime or fl...

Journal of Building Materials and Structures, 2019

Storey extensions are an increasingly popular way to crowded cities. Lack experience and knowledg... more Storey extensions are an increasingly popular way to crowded cities. Lack experience and knowledge concerning strengthening of structures are major challenges for engineers. This paper presents strengthening practice adopted for foundations of existing building when storey extension is needed. Literature concerning strengthening techniques commonly adopted and some historical cases were reviewed. A complex hall building in university of Khartoum which was rehabilitated in 2009 by strengthening the structural members of the existing building to accommodate additional floors was undertaken as a case study. The records and reports of the original design and last rehabilitation of the building were reviewed. Field inspection of the building condition before rehabilitation was carried out. The study results showed that the appropriate design, the strengthening materials used and the procedure followed are the key factors for economical and successful strengthening.

Recently many researchers used industrial waste in soil stabilization as low cost materials and t... more Recently many researchers used industrial waste in soil stabilization as low cost materials and to save the environment. In this regard, an attempt is made to evaluate the use of Marble Waste Powder (MWP) to stabilize expansive clay. Soil samples were mixed with varying proportions of MWP (0%, 10%, 15 % and 20% by dry weight). Laboratory experiments include sieve analysis, Atterberg's limits, Standard Proctor, Unconfined Compression Strength (UCS) and Free Swell were performed on treated and untreated soils. The results revealed that addition of 20% MWP to the soil significantly reduced the soil plasticity and free swell index by almost 12%, while the UCS greatly increased by almost 3.5 times of the initial value. It’s concluded that the use of MWP will improve the expansive soil properties and it is beneficial for economical and environmental considerations.

Crossing culverts are essential element of rural roads. The paper aims to investigate failures of... more Crossing culverts are essential element of rural roads. The paper aims to investigate failures of recently constructed wadi-crossing pipe culverts in Sennar state and provide necessary remedial measures. The investigation is conducted to provide an extensive diagnosis study in order to find out the main structural and hydrological weaknesses of the culverts. Literature of steel pipe culverts related to construction practices and common types of culvert failures and their appropriate mitigation measures were reviewed. A detailed field survey was conducted to detect failures and defects appeared on the existing culverts. The results revealed that seepage of water through the embankment and foundation of the culverts leads to excessive erosion and scouring causing sever failures and damages. The design mistakes and poor construction were detected as the main causes of culverts failures. For sustainability of the culverts, various remedial measures are recommended to be considered in ur...

This paper discusses a serious problem of traffic congestion in Khartoum in order to identify its... more This paper discusses a serious problem of traffic congestion in Khartoum in order to identify its causes and impacts on society and economy. The literature relating to the problem of traffic congestion were intensively reviewed. The research methodology have been adopted includes questionnaire, interviews and site visits. The data collected were statistically analyzed. The results indicated that the traffic congestion contributing to insufficient road capacity, lack of public transport and parking problems. It was found that traffic congestion has adverse effects such as time consuming, decrease in productivity and fuel consumption. Finally, some major measures were provided to reduce traffic congestion in Khartoum by expansion of roads, managing parking and adopting Bus Rapid Transit (BRT) system.

Zenodo (CERN European Organization for Nuclear Research), Sep 3, 2017

University of Khartoum Engineering Journal, Oct 31, 2022

University of Khartoum Engineering Journal, Aug 20, 2020

University of Khartoum Engineering Journal, Jun 12, 2017

University of Khartoum Engineering Journal, Apr 19, 2017

University of Khartoum Engineering Journal, 2016

International Journal of Materials Science and Applications, 2017

University of Khartoum Engineering Journal, 2017

University of Khartoum Engineering Journal, Jan 23, 2020

University of Khartoum Engineering Journal

Journal of Building Materials and Structures, 2019

D D Dr r r. . . m m ma a ag g gd d di i i Z Z Zu u um m mr r ra a aw w wi i i U U Un n ni i iv v ... more D D Dr r r. . . m m ma a ag g gd d di i i Z Z Zu u um m mr r ra a aw w wi i i U U Un n ni i iv v ve e er r rs s si i it t ty y y o o of f f K K Kh h ha a ar r rt t to o ou u um m m M M MA A AY Y Y

University of Khartoum Engineering Journal, 2018

‫ص‬ َ ‫ـلـ‬ ْ ‫َخ‬ ‫ْــت‬ ‫ـس‬ ُ ‫م‬ ‫من‬ ‫العديد‬ ‫األخيرة‬ ‫اآلونة‬ ‫في‬ ‫إجراء‬ ‫سيتم‬ ‫الصدد‬... more ‫ص‬ َ ‫ـلـ‬ ْ ‫َخ‬ ‫ْــت‬ ‫ـس‬ ُ ‫م‬ ‫من‬ ‫العديد‬ ‫األخيرة‬ ‫اآلونة‬ ‫في‬ ‫إجراء‬ ‫سيتم‬ ‫الصدد‬ ‫هذا‬ ‫في‬ ‫البيئة.‬ ‫علي‬ ‫وللمحافظة‬ ‫الثمن‬ ‫رخيصة‬ ‫كمواد‬ ‫التربة‬ ‫لتثبيت‬ ‫الصناعية‬ ‫المخلفات‬ ‫إستخدمت‬ ‫البحوث‬ ‫الوزن‬ ‫من‬ ‫(نسب‬ ‫الرخام‬ ‫بدرة‬ ‫من‬ ‫مختلفة‬ ‫بنسب‬ ‫التربة‬ ‫من‬ ‫عينات‬ ‫خلط‬ ‫تم‬ ‫المتمدد.‬ ‫الطين‬ ‫لتثبيت‬ ‫الرخام‬ ‫بقايا‬ ‫بدرة‬ ‫إستخدام‬ ‫لتقييم‬ ‫محاولة‬ ‫هي:‬ ‫و‬ ‫الجاف)،‬ ( 0 ، % 10 ، % 15 % ، % 20 ‫حدود‬ ، ‫المنخلي‬ ‫التحليل‬ ‫شملت‬ ‫معالجة‬ ‫وغير‬ ‫معالجة‬ ‫تربة‬ ‫عينات‬ ‫علي‬ ‫معملية‬ ‫إختبارات‬ ‫إجراء‬ ‫ثم‬ ‫الجاف).‬ ‫الوزن‬ ‫من‬ % ‫إضافة‬ ‫أن‬ ‫النتائج‬ ‫أظهرت‬ ‫الحر.‬ ‫واإلنتفاخ‬ ، ‫محصور‬ ‫الغير‬ ‫الضغط‬ ، ‫القياسي‬ ‫بروكتر‬ ، ‫أتربيرج‬ 20 ‫مؤشر‬ ‫في‬ ‫إنخفاض‬ ‫إلي‬ ‫أدت‬ ‫للتربة‬ ‫الرخام‬ ‫بدرة‬ ‫من‬ % ‫حوالي‬ ‫بنسبة‬ ‫الحر‬ ‫اإلنتفاخ‬ ‫ومؤشر‬ ‫اللدونة‬ 12 ‫حوالي‬ ‫كبير‬ ‫بمعدل‬ ‫محصورة‬ ‫الغير‬ ‫الضغط‬ ‫زاد‬ ‫بينما‬ % 3.5 ‫بدرة‬ ‫إسنخدام‬ ‫إن‬ ً ‫ختاما‬ ‫اإلبتدائية.‬ ‫القيمة‬ ‫ضعف‬ ‫إقتصاد‬ ‫مفيدة‬ ‫و‬ ‫المتمددة‬ ‫التربة‬ ‫خواص‬ ‫تحسن‬ ‫الرخام‬ ‫بقايا‬ ً ‫يا‬ ‫وبيئي‬ ً ‫ا‬ . ‫ال‬ ‫كلمات‬ ‫ال‬ ‫مفتاحية:‬ ‫التربة‬ ‫المتمددة،‬ ‫بقايا‬ ‫بدرة‬ ‫الرخام،‬ ‫التثبيت،‬ ‫الخواص‬

University of Khartoum Engineering Journal, 2018

Produced water associated with crude oil production is considered as waste water. In most of the ... more Produced water associated with crude oil production is considered as waste water. In most of the Sudanese oilfields processing facilities, evaporation ponds are used to store the produced water for evaporation or further treatments and reuse. The objective of this work is to study the probable effects of seepage into soil from existing evaporation ponds that were constructed many years ago to store produced water from field production facilities (FPFs) in five Sudanese oilfields. Seepage assessment methodology involved of electrical resistivity measurements, drilling boreholes and collecting soil samples at different depths, geotechnical laboratory tests, water and soil tests and finally incorporates all testing results and geophysical interpretations for each location into a computational model to predict seepage front in vertical and horizontal directions. Electrical resistivity method basically the vertical electrical sounding (VES) has been employed during this study. The geophysical work was carried out with sensitive Mini-Sting Resistivity meter manufactured by Advanced Geosciences Incorporation. More than 60 VES measurements were conducted using Schlumberger array. Geotechnical investigation program was carried out included field work and laboratory testing. The investigation started with the field work by drilling 10 boreholes, collecting representative disturbed and undisturbed soil samples. Soil profiles and the engineering properties of the subsoil were tested and interpreted. Water and soil samples were tested in two laboratories for environmental properties, pH, TDS, oil content and heavy minerals. Historical data about water quality from the evaporation ponds as well as from nearby water wells were collected and compared with the lab results. It was found that, the majority of these tests showed normal concentration of different chemicals in evaporation ponds, soil till depth of 15 meters and other oil wells till depth of 400 m. Thorough comparison of these test results indicates no seepage evidence in these waters and/or soils. Comparison is made by investigating old data with new data from several laboratories for TDS, pH and other constituents to see if there is considerable change with time. When comparing the test results to the national and international limits for pollution discharge, the obtained results are far below standard limits. Computational seepage model was created to predict seepage advancement in each location. It has been found that both the current seepage level and the predicted one will not reach the ground water static level in all five locations. Risk assessment was performed for five different scenarios. Generally, and according to the laboratory test results for the five locations, the likelihood for vertical or lateral seepage to contaminate ground/surface water and soil is rare, i.e. extremely unlikely or impossible.

—Determination of Resilient Modulus (M R) is quite important for characterizing materials in pave... more —Determination of Resilient Modulus (M R) is quite important for characterizing materials in pavement design and evaluation. The main focus of this study is to develop a correlation that predict the resilient modulus of subgrade soils from simple and easy measured soil index properties. To achieve this objective, three subgrade soils representing typical Khartoum soils were selected and tested in the laboratory for measuring resilient modulus. Other basic laboratory tests were conducted on the soils to determine their physical properties. Several soil samples were prepared and compacted at different moisture contents and dry densities and then tested using resilient modulus testing machine. Based on experimental results, linear relationship of M R with the consistency factor 'F c ' which is a combination of dry density, void ratio and consistency index had been developed. The results revealed that very good linear relationship found between the M R and the consistency factor with a coefficient of linearity (R 2) more than 0.9. The consistency factor could be used for the prediction of the M R of compacted subgrade soils with precise and reliable results.

Crossing culverts are essential element of rural roads. The paper aims ‎to investigate failures o... more Crossing culverts are essential element of rural roads. The paper aims ‎to investigate failures of recently constructed wadi-crossing pipe ‎culverts in Sennar state and provide necessary remedial measures. The ‎investigation is conducted to provide an extensive diagnosis study in ‎order to find out the main structural and hydrological weaknesses of ‎the culverts. Literature of steel pipe culverts related to construction ‎practices and common types of culvert failures and their appropriate ‎mitigation measures were reviewed. A detailed field survey was ‎conducted to detect failures and defects appeared on the existing ‎culverts. The results revealed that seepage of water through the ‎embankment and foundation of the culverts leads to excessive erosion ‎and scouring causing sever failures and damages. The design mistakes ‎and poor construction were detected as the main causes of culverts ‎failures. For sustainability of the culverts, various remedial measures ‎are recommended to be considered in urgent rehabilitation of the ‎existing crossings.‎

—Chemical stabilization is a technique commonly used to improve the expansive soil properties. In... more —Chemical stabilization is a technique commonly used to improve the expansive soil properties. In this regard, an attempt has been made to evaluate the influence of Calcium Chloride (CaCl 2) stabilizer on the engineering properties of expansive soil. A series of laboratory experiments including consistency limits, free swell, compaction, and shear strength tests were performed to investigate the effect of CaCl 2 additive with various percentages 0%, 2%, 5%, 10% and 15% for improving expansive soil. The results obtained shows that the increase in the percentage of CaCl 2 decreased the liquid limit and plasticity index leading to significant reduction in the free swell index. This, in turn, increased the maximum dry density and decreased the optimum moisture content which results in greater strength. The unconfined compressive strength of soil stabilized with 5% CaCl 2 increased approximately by 50% as compared to virgin soil. It can be concluded that CaCl 2 had shown promising influence on the strength and swelling properties of expansive soil, thereby giving an advantage in improving problematic expansive soil.

This paper aims to assess the efficiency of using geogrid reinforcement ‎for subgrade stabilizati... more This paper aims to assess the efficiency of using geogrid reinforcement ‎for subgrade stabilization. The literature of applying geogrid ‎reinforcement technique for pavements built on soft subgrades and the ‎previous experiences were reviewed. Laboratory tests were conducted ‎on soil reinforced with geogrids in one or several layers. The soil ‎specimens were compacted in four layers with or without geogrid ‎sheets. The California Bearing Ratio (CBR) test, in soaking condition, ‎was performed on natural soil and soil-geogrid specimens. The test ‎results revealed that the CBR value is much affected by the geogrid ‎sheet location and the number of sheets used in the soil specimen. ‎When a geogrid sheet was placed at the 1st layer of the soil, there was ‎an increment of 26% in the CBR value. Moreover, the CBR value was ‎significantly increased by 62% when geogridsheets were placed at all ‎four layers. The high CBR value is attributed to interface friction and ‎interlock involved in the geogrid/soil interactions. It could be ‎concluded that geogrid reinforcement is successful and more ‎economical technique.‎

This paper aims to investigate the important role of deep excavation support and its effect on ne... more This paper aims to investigate the important role of deep excavation support and its effect on nearby existing buildings, especially those founded on shallow foundations. Excavation of basement or foundations induces movements as a consequence of stress-release from earthwork and an increase in overburden pressure in the retained ground. Ground movements throughout excavation result in damage to existing structure located nearby. An intensive literature of previous experiences on supporting deep excavation and their impact on neighboring structures reviewed. This paper presents three case histories and two local current cases of excavations, which caused damages either on their own projects or on adjacent buildings. The results revealed that there are numerous sources of risk associated with performing deep excavations in urban areas, they must be considered in the design and execution of the excavation works for a minimum cost. General conclusions have been drawn from the study findings.

The aim of this paper is to investigate the strength characteristics of different types of soil b... more The aim of this paper is to investigate the strength characteristics of different types of soil by means of various laboratory and field tests such as CBR test, tri axial compression test, DCP test and vane shear test. The strength is affected by the soil properties and testing conditions. Various soils samples have been compacted at different placement conditions (i.e. water content and dry density) then using laboratory and field equipment to enable the measurement of CBR and shear strength of these soils. Analysis of the experimental data indicated that there is a very good linear relationship between the measured soil strength (i.e. CBR and shear strength) and the soil state factor as described by the combination of initial dry density, water content and void ratio. On basis of this linear relationship, a chart of CBR and shear strength – initial state conditions was developed. This chart can be used in design, evaluation and compaction control of various soils.

This paper is concerned with the study of swelling behaviour and strength characteristics of expa... more This paper is concerned with the study of swelling behaviour and strength characteristics of expansive soils in order to develop new design charts. Expansive soil samples with high plasticity have been compacted at a wide range of water content and different dry densities. A new characterisation concept was developed.

—The aim of this paper is to predict the field CBR of different types of soils. Since CBR can't b... more —The aim of this paper is to predict the field CBR of different types of soils. Since CBR can't be easily measured in the field, prediction of CBR from other simple tests such as Dynamic Cone Penetrometer (DCP) and soil properties is a valuable alternative. Various soils have been compacted at different initial state conditions (i.e. water content and dry density) then using laboratory and field equipment to enable the measurement of unsoaked CBR and DCP of these soils. Analysis of the experimental data indicated that there is a very good linear relationship of the measured soil strength (i.e. unsoaked CBR and DCP) with the soil initial state factor as described by the combination of initial dry density, water content and void ratio. Comparison of the measured and predicted values of unsoaked CBR and DCP using the developed equation clearly indicates the validity of this equation. Index Terms—Dynamic cone Penetrometer (DCP), in-situ CBR and the soil initial state factor.