ABSTRACT. Abstract: The Blue Nile steel bridge over the Blue Nile river in Khartoum State has been in surface for over 109 years. The bridge crosses the river at right angles, connecting Khartoum and Khartoum North. The bridge has a total length of 559 m and an overall width of 16.05 m between centers of trusses. Many strength assessment studies for the structural condition of the bridge were carried out. The first recorded study being in 1960, followed by studies on 1975,1981,1994,2004,2008 and 2009. All these studies revealed serious problems in some elements of the bridge. These elements include superstructure, bearings and substructure. All studies recommended repair and rehabilitation of the affected parts of the bridge. A rehabilitation program began on October 2017 to extend the life of the bridge for another 50 years. This paper includes a literature review on strength assessment of the bridge members, the method of selecting the rehabilitation strategy for the bridge along with the methodology by which main members were identified for strengthening or replacement. The strengthening of the existing side walk to be converted into roadway for private small cars is presented. The need to respect the appearance of the main members of the bridge to meet historical protection was respected. Due to the congestion created by closing the bridge, the need arise to reopen the bridge as quickly as possible. This dictated using strategies and construction methods to achieve the goal of opening the bridge to traffic partially in short time. These strategies and methodologies are presented. Lessons learned during assessment, design and construction stages are outlined, and recommendations are presented for the strength assessment of corroded members based upon results on the literature survey and experience obtained during execution of the rehabilitation of the bridge.

ABSTRACT. This paper tackles load rating process on one of the most important bridges in Sudan, which is the Salvation Bridge over the White Nile in Khartoum. The paper reviewed the main load rating types adopted by AASHTO standards. Design load ratings have been made with respect to AASHTO-LFRD highway live loads, BS-5400 highway live loads and Euro code highway live Loads. Legal load rating process has been made using the Sudanese legal loads adapted by National Highway Authority in Sudan. Permit load rating process has been made using actual special trucks used in Sudan during the last 20 years .The rating process has been made on the assumption that the capacity of the main structural elements of the bridge had been decreased with different percentage from zero at 50%, due to different factors. A suitable software has been used for calculations and the results are presented. The paper predicted the load rating factors for the bridge for considerable capacity loss in future and suggested several recommendations to save such vital structure.

ABSTRACT. In this research seismic analysis of beam-type bridges in Sudan was studied. Burri, Al Manshia and AlDamer Bridges were taken as case studies to investigate seismic effects. The first two bridges were constructed at Khartoum State in the years 1972 and 2001 respectively. The third bridge was constructed at River Nile State in the year 2008. The selected bridges represent prestressed concrete box and I-Girder beam-type bridges. Finite Element models for the three bridges were built. The seismic analysis was performed by two methods, direct integration time history analysis and response spectrum analysis. The Response Spectrum for Central Khartoum, Sudan proposed by Y. Mohamedzein, et al. [7] was considered for the analysis. A SIMQKE [6] program was used to artificially simulate earthquake motions compatible with the prescribed response spectra. A computer program has been developed in MATLAB and was used to analyze the problem under research. The Commercial Structural Analysis SAP2000 program [11] was also used for the comparative study and it was found that it gave typical results. The developed software has been found to be efficient, reliable and easy to apply. It was found that bridge response in terms of displacements, shear and moments was directly proportioned to the peak ground acceleration (PGA). Also it was found that time history analysis and response spectrum analysis almost gave the same results. Due to the ease of implementation, the response spectrum method is recommended for the evaluation of seismic effects on the studied bridge types. Where nonliterary may exist such in piers and abutments it is recommended to use nonlinear time history analysis to evaluate seismic effects. For future research it is recommend to design response spectra for other areas of Sudan. Also it is recommended to make use of the developed software for other types of bridges. ملخص يتناول موضوع البحث دراسة التحليل الزلزالي لجسور العارضات بالسودان. تناول البحث بصورة تفصيلية دراسة حالة جسري بري والمنشية الذَين تم تشييدهما في ولاية الخرطوم في العامين 1972 و2001 على التوالي و كذلك جسر الدامر الذي تم تشيده بولاية نهر النيل في العام 2008 . الجسور المختارة تمثل جسور الخرسانة مسبقة الإجهاد الصندوقية و الجسور التي على شكل I . تم بناء النموذج بطريقة العناصر المحددة لكل جسر. تم إجراء التحليل الزلزالي بطريقتي مخططات طيف الاستجابة وطريقة التكامل المباشر لمعادلة الحركة. مخطط طيف الاستجابة المحسوب بواسطة د. يحي محمد زين وآخرين لمنطقة الخرطوم تم أخذه كمدخلات للتحليل الزلزالي. تم استخدام برنامج SIMQKE لتوليد ومحاكاة زلازل متوافقة مع مخطط طيف الاستجابة. في هذه الدراسة تم بناء برنامج للحاسوب بلغة ماتلاب للتحليل ومن ثم طبق البرنامج على الحالات مثار البحث. تم استخدام برنامج SAP2000 لمقارنة النتائج وقد وجد أنه يعطي نتائج مطابقة للنتائج المتحصله من البرنامج الذي صممه الباحث. وجد ان البرنامج الذي تم تطويره يتسم بالفاعلية والاعتمادية وسهولة التطبيق. وجد في البحث عند التحليل الزلزالي للجسور أن استجابة الجسر من حيث الإزاحة وقوى القص وعزوم الانحناء تتناسب تناسباً طردياً مع أقصى تسارع أرضي (PGA). كما وجد أيضاً أن نتائج التحليل بطريقة التكامل المباشر لمعادلة الحركة والتحليل بطريقة طيف الاستجابة تعطي نتائج شبه متطابقة. لسهولة تطبيق طريقة طيف الاستجابة يوصى بها في التحليل الزلزالي لهذا النوع من الجسور. لدراسة الأثر اللاخطي في مكونات الجسر الأخرى مثل الأكتاف والدعامات يوصى باستخدام طريقة التحليل اللاخطي لمعادلة الحركة. يوصى البحث مستقبلياً بتصميم مخططات أطياف استجابة لمناطق السودان المختلفة. كما يوصى باستخدام البرنامج المطور في هذه الدراسة لدراسة الأثر الزلزالي للأنواع الأخرى من الجسور.

ABSTRACT.  المستخلص قطاع التشييد من أخطر قطاعات العمل في العالم، وقطاع تشييد الطرق والجسور أحدى قطاعات البنى التحتية للدول، ونجد أن السلامة المهنية في هذا القطاع عامل مهم للتقليل من الخسائر. ولذلك فإن السلامة والصحة المهنية أحدى متطلبات التطبيق السليم للأعمال في قطاع تشييد الطرق والجسور وهي القناع الواقي لجميع الأفراد والعاملين ضـد الأخطـار والحوادث، وعليه لابد أن يكون جميع الأفراد على وعى كامل وإقتناع بقيمة مفاهيم وأسس السلامة والصحة المهنية وذلك لتجنب حدوث الإصابات والحوادث. وكثير من المخاطر التي تحيط بقطاع تشييد الطرق والجسور في السودان لا بد من الاهتمام الى كيفية إدارتها والاستجابة لها ومقارنتها مع المخاطر التي تحيط بقطاعات أخرى وتحديداً قطاع البترول، وذلك للإستفادة في كيفية إدارة المخاطر والإستجابة لها في البني التحتيه، وحث أصحاب القرار والمسئولين والقائمين على الأمر بالقيام بواجبهم على أكمل وجه وذلك بوضع وصياغة إجراءات السلامة المهنية وأتباعها للحد من المخاطر وتقليل الخسائرفي قطاع تشييد الطرق والجسورفي السودان وهذا ماناقشته هذا الورقة.

ABSTRACT. This paper, is a part of continuous research, aims to examine the suitability of cast-in-place ferrocement composite slab as a roof/ floor system. The continuous study is mainly based on experimentation. Ferrocement is a combination of cement/sand (1:2.5) mortar, having a compressive strength higher than 30 N/mm2, and expanded metal with R6mm bars, can be utilized in any from and shape not more than 50mm thick. Two Floor panels each consist of a 50mm slab casted over corrugated zinc sheet of 1.0m width and 4.5m length supported by central two rectangular steel pipes spaced 50cm along the long side. The pipes were connected to the panels by self-drill screws and shear keys. Steel pipes were (120mmx60x1.8mm) and (100mmx50x1.8mm) for each panel A and B respectively. For Cast-in-place technique, the whole floor will be casted in a single day, whereas, precast panels requires forms and handling effort. Panels were tested using 50kg cement bags as a uniform distributed load. The experimental results show that panels have enough strength and can be used, within the allowable service deflection limit, as a roof/ floor system.

ABSTRACT. This paper addresses long-term deflection of reinforced concrete slabs.A method of predicting deformation using EC2 model is presented.A spreadsheet program that simulates the deflection of simply supported one-way slab is developed.The model is then used to carry out a parametric study to identify different factors on slab deflection.It has been found that the most significant factor that influences deflection is the slab thickness.

ABSTRACT. بسم الله الرحمن الرحيم ورقة علمية فى مجال إدارة التشييد بعنوان التحديات التي تواجه الشخصية المهنية للمهندس المدني في السودان مستخلص

دور الهندسة المدنية في السودان يمكن ملاحظته من خلال الأعمال التي يقوم بها القطاعين العام والخاص في المجالات الإستشارية والتنفيذية وينعكس إسهام هذا القطاع على الناتج الإجمالي القومي للبلاد إذ أن معدلات النمو الإقتصادى توضح جلياً الدور المحورى لقطاع الإنشاءات الهندسية فيما يقدمه من أعمال وخدمات تصب فى عملية دعم الإقتصاد الوطنى . يمثل المهندس المدني إحدى الركائز الأساسية في الهرم الإداري والوظيفي للمشروعات ذات الطابع الهندسي وقل ما يكون هنالك مشروعاً تنموياً يخلو من هذا التخصص فالأدوار التي تمليها الضرورة علي المهندس المدني تتسم بالشمولية وذلك بحكم تداخل الجوانب الإدارية والمالية والقانونية فضلاً عن الجوانب الفنية في عملية إدارة المشروعات, وهذا يقتضى , بالضرورة , أن يكون المهندس المدنى مؤهلاً بقدر كاف لمقابلة المهام والأدوار الموكلة إليه.يأتى فى صلب هذا التأهيل المعرفة الأكاديمية بجانب المقدرات المهارات المهنية المكتسبة وغير المكتسبة. إهتمت هذه الورقة بدارسة الشخصية المهنية للمهندس المدني في السودان إنطلاقاً من المهام الموكلة إليه والتحديات التى تواجهه فى ظل الإمكانات العلمية والمهنية والمهارات المتاحة من خلال البيئة الأكاديمية والتدريبية المكونة لشخصيته المهنية . لاحظ الباحث من خلال الممارسة العملية لصناعة التشييد في السودان بالقطاعين العام والخاص فى بعض ولايات السودان أن هنالك تحديات وصعوبات جمة تواجه المهندس المدني وتحول دون تحقيق النتائج المستهدفة مما تجعله مغلول اليدين تجاه كثير من الوقائع الإدارية والقانونية ومن المسببات المحتملة وراء ذلك الوضع السالب ضعف التأهيل الأكاديمي والمهني والنقص فى المهارات المصاحبة وهذا الوضع يعمل علي خلق العديد من المعضلات التي تعيق نجاح المشروعات . هدفت هذه الدراسة إلي تقييم التحديات التي تواجه الشخصية المهنية للمهندس المدني في السودان وتحديد أطر عامة يمكن من خلالها التقليل من الآثار السالبة للأداء وصولاً إلي مرحلة المهنية المعيارية في ممارسة الأعمال في تخصصات الهندسة المدنية . تم , بجانب الإطار النظري , جمع البيانات الأولية من مجتمع الدراسة عن طريق توزيع إستبيان على عينة عشوائية من مجتمع الدراسة بمنهجية التحليل الوصفى وتوصلت الورقة إلي أن هنالك قصوراً في أداء الكادر البشرى فى مجال الهندسة المدنية متمثلاً فى ضعف المؤهلات الفردية للمهندس وذلك بسبب عدم شمولية المناهج التعليمية والنقص في برامج التدريب المنهجي وعدم الإهتمام بتوفير دليل للخبرات التراكمية فى مجال المشروعات الهندسية علاوة على أسباب أخرى. أوصت الورقة بأن تتم مراجعة المناهج الأكاديمية وإدخال المواد ذات الصلة دون الإخلال بالتخصص الأساسي كما أوصت بضرورة إنشاء جسم يتبني عملية تأهيل خريجي الهندسة المدنية من حيث التدريب المنهجي والإعداد الجيد للممارسة المهنة . كما أوصت الدراسة بضرورة مراجعة أسس الترقى للدرجات المهنية بالمجلس الهندسى ووضع معايير تشمل الإمكانات المتعلقة بالمعرفة الضمنية والمهارات التطبيقة.

م.م.د/ صلاح الدين عبد العزيز عجبان أ.مساعد 2 يناير 2018 م

ABSTRACT. Gash River, in Eastern Sudan - Kassala state, is a seasonal flashy river. It originates from the Eritrean highland and flows during the period from early July up to end of September. The river divides Kassala city into two parts namely; the eastern and western parts. Flood water frequently inundates the city, causing a lot of losses for humans, livestock and property. Despite the intensive flood protection works, the city is still under a high risk of flooding. The decrease of rain gauge networks and absence of river flow observations in the basin made the rainfall-runoff study a challenging task. This study is a preliminary analysis of the potential for using satellite derived data for hydrological modelling of the basin. Satellite Rainfall Estimate (SRE) data sets in Gash river catchment is obtained from two sources namely; Tropical Rainfall Measurement Mission (TRMM-3B42RT) and Global Satellite Mapping of Precipitation (GSMaP_NRT). The SRE data sets are freely available in public domain. Observed hydrograph at the catchment outlet was compared to the areal average SRE from the two data sets for daily and/or hourly time steps. For more than 80 % of the events, the comparison of the peak rainfalls with the peak discharges showed a reasonable agreement between the two peaks. This result reflects the high potential for SRE data sets to be used as input for hydrological modeling and flood forecasting Gash river and the other basins with similar characteristics. The Hydrologic Engineering Center Hydrologic Modeling System (HEC-HMS) software can be used a forecasting tool.

ABSTRACT. ABSTRACT The reservoir storage loss caused by sedimentation is a critical problem for those reservoirs which are expected to provide Hydro-power. Hence, it is getting more important to promote sustainable sedimentation management in the near future. The main research objectives are to use data for reservoir and dam, to provide an approach for policy formulation used in decision making. At the same time, it also prompt policymakers stand at the national level to recognize the importance of reservoir storage protection. It worth mentioning that, in this research, the output of a calibrated/validated hydrodynamic model is judiciously applied as an input to a reservoir conservation model (RESCON). The key algorithm of the model is an economic optimization function, supported by engineering relationships that allow the quantification of basic parameters. The management strategies were assessed further with RESCON model. Removing a portion of sediment at Merowe for the downstream river reach maintenance was considered, but because of small head available for hydro suction, it was found practically impossible to achieve a worthwhile result in removing sediment through HSRS. Sediment removal through flushing was found technically infeasible for flushing discharge lower than 2000 m3/s and duration of flushing of 35 days. In addition to its technical feasibility, i.e. it is not possible to completely flush the deposit due to its impacts on the downstream users. Among the available alternatives dredging was found technically feasible, and it retains maximum long-term capacity but only on its second cycle (year). Based on the RESCON model estimates, 18 dredges capable of removing 189 million m3 per year each must be installed to keep the reservoir sustainable.

ABSTRACT. The Ethiopian Government began constructing The Grand Ethiopian Renaissance Dam (GERD). This dam is expected to affect Sudan which is dependent on the Blue Nile. In this situation there is a clear need to assess these downstream impacts. Against this background, a simulation and optimization model for a multi-purpose cascade of reservoirs has been developed to provide an optimal operation of the Blue Nile System in Sudan for both current and future situation (before and after GERD becomes operational) under three scenarios (dry, average and wet years). Two objectives were considered in the development of this optimal operation: maximizing hydropower generation and maximizing the new irrigation area that becomes potentially available after the heightening of Roseires. The model was called the Excel-based Blue Nile Simulation and Optimization Model or EBSOM. The results of EBSOM before GERD becomes operational showed that the maximum area that could be planted was 525,000 hectares. This area will decrease the annual energy production of Roseires reservoir by 9.1% at minimum and 23.5% at maximum. The results showed that if the filling and operation of GERD is carried out in consultation with Sudan and Egypt, it can be expected that there will be several benefits especially in terms of irrigation and hydropower generation. However, there are also some negative consequences that need to be further studied and addressed.

ABSTRACT. The construction of Ethiopian Dams, GERD (Grand Ethiopian Renaissance Dam) and Karadobi, will definitely cause many impacts on Sudanese dams on the Blue Nile during initial filling and full operation of the two Ethiopian dams, respectively. The flow of the Blue Nile , entering Sudan (upstream Roseires Dam), will be regulated so that the flood hazard will not be there, as the Blue Nile flow will be in the range (100-200 million cubic meter per day) compared to the high flood discharges (800-1000 million cubic meter per day) during the last period of August. A mathematical model has been developed using GIS software tools (HEC-GeoHMS and HEC-HMS 4.0) and Rainfall characteristics data for 12 sub-catchments for Blue Nile system within Ethiopia. This model has been used to forecast water inflows coming at GERD before and after the construction of Karadobi dam. Therefore, releases downstream GERD that entering Sudan will be known. It is worth mentioning that the GERD full capacity is 74 Billion cubic meters and the generated power is 6000 MW, as Karadobi dam which has not been constructed yet with full capacity of 40.22 Billion cubic meters and the generated power is 1600 MW.

Dr.Adil Mohamed Elkhidir*, Ahmed Hassan Aboalbasher Ali**, Ahmed Adil Eltayeb Abd-Elnour**, Osama Gism Elseed Bahkeet** *Associate Professor, Civil Department –Faculty of Engineering- University of Khartoum ** Graduated in 2017 - Civil Department –Faculty of Engineering- University of Khartoum

ABSTRACT. The aim of this paper is to conduct an economic assessment of the impact of GERD dam on hydropower generation in Sudan considering both Merowe and Roseires reservoirs for assessment. A model was developed using RiverWare software from the University of Colorado to conduct hydrological simulations of all water systems in Sudan. After calibrating the model, the cost of the sediment, the operating cost of the generation and the alternative cost of thermal generation of the lost opportunities were calculated. An economic assessment of reservoirs operation options at higher levels during flood was carried out using the simple benefits and cost ratio method. The study concluded that raising levels during the flood to 471m and 291m above sea level  in Roseires and Merowe will be adequate enough for passing considerable amount of the sediment in long-term (30 years) and is the most economically viable for both sustainability of these reservoirs and the maximization of hydropower generation. In addition, a great opportunity is available to increase generation at these plants by 24% (2000 Gig watt/year) compared to the average before GERD Dam and is expected to contribute to the Sudanese economy's annual savings by 23 million US dollars as an opportunity value.

ABSTRACT. The aim of this research is to study and investigate the impacts of GRAND ETHIOPIAN RENAISSANCE DAM, commonly known as (GERD), which is located in Ethiopian-Sudanese border, on the sediment transport within the downstream reservoirs in Sudan, taking Merowe Dam as a case study. The GERD impacts were analyzed by developing a hydrodynamic/Sediment model based on the past and projected hydrological conditions. It worth mentioning that, the authors of this paper have developed logical scenarios in order to estimate inflows to be applied at the upstream reservoir boundary. Never the less, the releases and outflows at the downstream boundary were used to develop a calibrated-validated hydrodynamic model. The hydrodynamic model was coupled with the sediment model to route sedimentation process within the reservoir for the given hydraulic conditions and the expected dam operation rules. The impacts are presented in terms of water levels, the morphological river bed changes and the deposited sediment volumes within the reservoir as well as the expected yearly sedimentation rate before and after GERD construction and operation.

ABSTRACT. مع تعقد سبل كسب العيش والتحضر كثر تدخل الإنسان فى الجريان الطبيعى للنيل بإقامة عدد من المنشاءات المائية للأغراض المختلفة والمتضاربة فى أغلب الأحيان. مثال لذلك إحتياجات الدول المتشاطئة للرى والتوليد الكهرمائى ودرأ الفيضانات والجفاف والتغير المناخى. ولتجويد التخطيط للإستفادة المثلى لهذا المورد الحيوى المشترك، كان لا مناص من التنبؤ مبكراً بإيراد النيل عند مآخذ هذه المنشاءات. الورقة تقدم نموذجاً رياضياً للتنبؤ بإيراد نهر النيل عند المواقع الرئيسية حتى السد العالى بناءاً على التنبؤ بإيراد النيل عند دخوله للسودان على ان يكون التنبؤ فى أكتوبر بعد انحسار قمة الفيضان ويستمر حتى نهاية السنة المائية فى يونيو. باستخدام النموذج أمكن مراجعة الفواقد للجريان الطبيعى والتبخر والتشرب وحساب سحب السودان فى كل أحباس النيل. كما أمكن مراجعة ومقارنة وتقويم قياس إيراد النيل عند المواقع الرئيسية التى تقوم بها الأجهزة التنفيذية للهيئة المشتركة لمياه النيل ممثلة فى إدارة مياه النيل والرى المصرى بالسودان. تقارن الورقة النتائج التى يصل اليها النموذج مع الإيراد الفعلى عند المواقع الرئيسية المياه الواسلة للسد العالى فى سنوات مختلفة الإيراد مقارنة مع مانصت عليه إتفاقية 1959. يتميز النموذج بالمرونة التي تسمح بإعادة حساب الإيراد عند المصادر وقيمة الفواقد المائية وسحب السودان تحت ما إستجد من أعمال وكذلك إذا ما جد أي جديد علي نهر النيل وروافده في المستقبل.

ABSTRACT. مستخلص أساسات المبنى تكون عاده معرضة لهبوط التربة وإنتفاخها بشكل منتظم أو متفاوت. الهبوط والإنتفاخ تسبب إجهادات عالية في عناصر المبنى. يصنف الهبوط والإنتفاخ كسبب رئيس لفشل المنشأت وسبب مشاكل عدم إستقرارها. هذا البحث يبحث أثر إستخدام الكمرات الرابطة بين الأساسات لتحسين مقاومة المنشأت للهبوط والإنتفاخ بإستخدام طريقة التحليل العددي. في هذا البحث تمت دراست حالتين. الحالة 1 مبنى من الخرسانة المسلحة تعرض لهبوط متفاوت بسبب حفر جزء من المبنى لإنشاء قبو. الحالة 2 مبنى من الخرسانة المسلحة تعرض لإنتفاخ متفاوت نسبة لزيادة المحتوى المائي للتربة المنتفخة. في الحالتين حدثت تشققات خطيره وإزاحات في الأساسات. إستخدم برنامجSAFE للتنبؤ بهبوط وإنتفاخ الأساسات حيث تم التركيز علي نتائج قوي العزوم والقص وحساب الإزاحات. كما إستخدم برنامج ABAQUS للعناصر المحدده لحساب إزاحة الأساسات والإجهاد الذي حدث للتربة في الحالة 1. تم إستخدام الكمرات الرابطة لحل مشكلة في الحالتين لمنع الهبوط والإنتفاخ مرة أخرى. صمم مقطع الكمرات الرابطة من الخرسانة المسلحة في الحالة1 و كمرات مغلفة في الحالة 2. النتائج توضح أن الكمرات الرابطة تقلل الهبوط المتفاوت و الإنتفاخ المتفاوت بصورة كبيرة.

Abstract: Building footings are usually susceptible to soil settlement and swelling, uniform or differential. The settlement and swelling causes higher stresses in building elements. The settlement and upheave are classified as main reason for structure failure and serious instability problems. This research investigated the effect of strap beams on improving structural resistance to settlement and upheave using numerical methods of analysis. Two cases of problems were considered. Case 1 is a R/C building subjected to differential settlement due to excavation for part of the building to construct a basement. Case2 is R/C building subjected to differential upheave due to increase in the moisture content of the expansive soil. For both cases severe structural cracks and displacement of foundations had taken place. SAFE program was used to predict the settlement and upheave of the foundations for the two cases concentrating on the results of the moment, shear force and the displacements. ABAQUS program for finite element was used to calculate the displacement of foundations and stress introduced in the soil in case1. A strap beam is used to solve the problem for the two cases. The sections of the strap beam used were concrete strap beam and cased beam for case1 and case2, respectively. The results indicate that strap beam can reduce the differential settlement and differential upheave greatly.

ABSTRACT. This paper presents an experimental study on the behavior of lightweight aggregate concrete-filled steel tubes (LACFT) under eccentric loading. 54 circular specimens with different load eccentricity distances (10, 20 and 35mm); steel ratio (11.4 and 13.5); and slenderness ratio (L/D = 3, 7, and 14) tested to examine the bearing capacity. Significant parameters influencing LACFT column's bearing capacity, failure mechanism and failure mode all studied and analyzed. Comparison between the predicted results by AISC-LRFD and CHN DBJ 13-51-2003 (2003) codes showed lower and applicable bearing capacities with slightly overestimated values for L/D≥14 than that measured during the experiments respectively, while the results gained by CHN CECS 28:90 showed a good agreement with the experimental results and slightly overestimated the values for L/D≥ 14 too. This study shows that bearing capacity of LACFT steel columns subjected to eccentric loading is conservative.

ABSTRACT. Since 2011, many civilian buildings in Arabian Countries exposed to damages due to explosion forces which have been for long time especially related to the military important. But today more important trend shall be taken towards such type of extreme load. The importance shall not only considered the design of the buildings to resist the blast loading but also damaged building after the explosion shall be evaluated for usability and safety as soon as possible.

The purpose of this study is to develop a methodology for post-blast damage evaluations and safety assessment of reinforced concrete building. To meet this goal and due similar characteristics of the Blast and Seismic loadings, comparison study has been conducted. The post-earthquake damage evaluation methodologies have been adapted and modified for post-explosion damage.

ABSTRACT. This paper deal with the yield line analysis of orthotropic reinforced concrete two-way slab under the effect of uniformly distributed pressure load. The analysis was based on the method developed by Johansson, in which a general formula was derived to calculate the ultimate moment for the slab. The Johansson formula enables the calculation of the positive moment in the short and the long direction of the slab while the negative moments are calculated using the positive moment and the edges ratios. It is worth mentioning that these ratios are unknowns and have been left to chosen by the designer. Also, these ratios were used to generate nine different cases describing the edge conditions of the slab panel, these cases are like the cases listed in BS8110. This paper contributed to estimating of these ratios by analyzing the values of the moments for the nine cases, which have been obtained using STAAD-Pro software by selecting the positive moment of the long span as a base value and finding the ratios between the moments according to it. Accordingly, a general formula for the ultimate moment was derived. This formula was based on three unknown dimensions of slab panel in both directions, these dimensions constitute the expected collapse pattern of the rectangle slab panel, taking into account all conditions for the nine cases. Using the rules of differential equations to find the maximum values, the values of the three dimensions were calculated in order to give the maximum bending moment, this has been done by following tedious calculations with using spreadsheet Excel software. Also, by using CurveExpert Program, simple equations depend only on spans ratios, have been derived for the unknown dimensions and for the ultimate moment. The results obtained using the yield line method were compared to those obtained using STAAD Pro program and those extracted from the BS8110. The yield line results as compared with the BS8110, were found less by an average of 22% for the positive moment for short span and 30% as average for the long span and about 15% less for the negative moment for the two spans. The results emphasized the well-known concept of yield line method which it stated that it is more economical method when used for calculating the bending moment for the purpose of designing two-way slab.

ABSTRACT. Deterioration of reinforced concrete structures caused by chloride-induced corrosion is one of the main problems for durability in reinforced concrete structures. Recent researches demonstrate that position and size of anode and cathode angles have strong influence on crack pattern and corrosion rate. All previous researches considered studying the influence of different anodic angles numerically but no experimental investigation was found. In the present paper, the influence of different anodic angles on corrosion crack pattern and corrosion rate will be investigated experimentally by applying accelerated corrosion test using impressed voltage technique to centrally reinforced concrete cylinders with different anodic angles (360°, 180° and 60°). Current-Time relationship, percentage of steel mass loss and bond strength of the corroded samples will also be discussed. The results show that the different anodic angles have strong influence on the corrosion crack pattern and corrosion rate and the developed experimental techniques can be used to investigate that influence. The results also show the mass loss with respect to different anodic angles. Also, it is found that the corrosion increases the bond strength for anodic angle of 60° and decreases the bond strength for anodic angle of 360°.

ABSTRACT. Abstract: Maturity method is a technique to account for the combined effects of time and temperature on the strength development of concrete. The method provides a relatively simple approach to estimate in-placed concrete strength. The purpose of this paper is to review basic concept of maturity, calculation methods & theories, focusing on using sensors at different regimes (curing and compaction) and discusses the results to prove if the sensors can give accurate predictions of strength measurements of concrete at different conditions and to study the effect of ambient temperature.

ABSTRACT. There is a limitation in the existing models that deal with fine sediment transport in irrigation canals. Most of the sediment transport models are developed for estuaries and rivers. Therefore there was a great need to develop a simple but effective numerical model that incorporates control structures to simulate the fine sediment transport in irrigation canals. One dimensional numerical model Fine SEDiment Transport (FSEDT) dealing with fine sediment transport in irrigation canals has been developed. The model has been used as a tool to study the mechanism of water and sediment flow under different operation and maintenance scenarios. The water surface profile has been predicted by using the predictor corrector method to solve the gradually varied flow equation. The prediction of sediment concentration is based on the solution of the one dimensional advection-diffusion equation. The change in bed level was computed based on the sediment mass balance equation that was solved numerically by using the finite difference method. The model has been applied in the Gezira Scheme. On the basis of the field data the model has been calibrated and validated. The predicted bed profiles depict good agreement with the measured ones. The model is capable to predict the bed profile for any period of simulation.

ABSTRACT. Floods are one of the major environmental problems that cause disasters in Sudan. In 2013, heavy rains had fallen across the country since the beginning of August, although rains at this time of the year are common, that year they had been heavier than the average and results in a serious damages and loss of lives in many states. East Nile locality in Khartoum state was one of the most affected areas, many people lost their lives and thousands left homeless as their houses were demolished.

This study was carried out to revise the existing drainage system and redesign inadequate sections. The study area consist of “Wadi Suba” with special reference of El-Silait Agricultural Project, which is located on the east of Blue Nile within Khartoum state. It is one of the main food security projects, with a total area of approximately 16,500 feddans (6,523 hectares) and a further extension area. The scheme suffered a serious damage as a result of the devastating floods that engulfed the area following the heavy rains that year (2013).

Digital hydrological maps for East Nile Locality were generated using Geographical Information System (GIS), and the catchment area of Wadi Suba was determined. Maximum daily rainfall data was analyzed for a period of 100 years (from 1901 to 2000) to determine the maximum design discharges of Wadi Suba for different return periods (5, 10, 25, 50, and 100 years). Moreover, the drainage discharges from agricultural areas were calculated using the generated drainage formula for the agricultural project.

The flood control system had been revised by checking the adequacy of the drainage system within El-Silait Agricultural Scheme, which consists of Flood Entrance, Land drains, El-Silait main canal’s Siphon, and the Two Highway Culverts.

ABSTRACT. In this research paper the Empirical Drainage Formula (Q= CAn) have been developed for 26 stations in Sudan using the rainfall characteristics for different regions. In general, the developed Project Drainage Formula (Q= CAn) will be used to design hydraulic structures of the drainage system such as culverts, siphons or drains for the considered irrigation project. Balance equation of drainage system for the considered irrigation project has been used to estimate the values of runoff factor ‘C’ and the exponent ‘n’ respectively at different return periods (2, 5, 10 and 20 years) .The balance equation includes the design maximum 2-day rainfall, soil moisture deficit and 2-day وcrop Evapotranspiration . The value of exponent “n” has been found as 1.0 for all stations with different values of “C” depend on the location of each station. Isohyetal maps for values of C at different return periods (2, 5, 10 and 20 years) have been developed for Sudan. Based on the location of proposed irrigation project region the appropriate value of C will be selected from the Isohyetal maps.

ABSTRACT. The Sudan Plantations Syndicate and then the Sudan Gezira Board have over the last 90 years diversified and intensified cropping pattern & cropping intensity in the Gezira scheme from the original crop cotton production. Due to Gezira scheme act, 2005 a lot of problems in cropping pattern and cropping intensity have arisen. The Gezira Scheme Act, 2014 return the selection of cropping pattern and cropping intensity to the board of directors. In season 2007-2008, about 1700 WUAs were established throughout the scheme due to Gezira scheme act, 2005. Unfortunately from 2007 onwards there was no formal way of crop rotation as in the past, whereby some farmers have kept the past rotation, and others not. As a result it was observed that more than one crop have been grown within a "Number" that previously had been devoted to only one specific crop in a season. This no crop rotation phenomena had affected to a great extends the indenting system in Gezira scheme. For good water management two conditions are very important; - A "Number" should be planted with one crop or divided between simultaneous crops, also indenting system in Gezira scheme should benefit from the crop water productivity model (Aqua Crop). - Cropping pattern (Agriculture plan) should be planned so that the crop water requirement with losses for agricultural area irrigated by a minor canal doesn’t reach its maximum capacity of minor canal.

ABSTRACT. White Nile schemes are a significant portion of irrigated agricultural projects sector in Sudan, those schemes are affected by the operation of Jebel Aulia dam; they depend on pumping water from J.A. reservoir via intake canals. The main objectives of this study is to increase the irrigated areas and to improve the performance of the irrigation systems for the White Nile irrigated agricultural schemes. Utilizing Landsat imagery; the area of Jebel Aulia reservoir had been calculated for the full and empty reservoir conditions respectively and the areas of islands had been also calculated for both conditions. Based on the comparison between the two conditions and considering the islands areas’, the recession areas which are potential for reclamation had been identified. Those reclaimed areas can be used for multipurpose; such as irrigation projects, fisheries and recreation areas. Within the recession areas; 17 dikes with different lengths ranging between 4 Km to 67 Km; had been proposed with maximum water command not exceeding 5 meters. Therefore 17 potential irrigation projects had been identified. Tentative cost had been estimated for each dike, from which unit rate per reclaimed feddan was calculated. Accordingly, the projects (Dike + Irrigation Project) have been ranked as per unit rate cost of reclaimed feddan. The advantages of these projects are several; such as the development of new potential irrigation areas which can be partially or fully irrigated by gravity from J.A. reservoir, reduction in seepage and evaporation losses from J.A. reservoir in addition to availing sustainable pumping systems for the existing and future White Nile irrigation projects.