تمثل الطرق العمود الفقري للبلاد والذي تتمحور حوله وحدة البلاد ونموها وتطورها ، ومما لاشك فيه بأن وجود شبكة متطورة من الطرق في الدولة يمكنها من تحقيق أهدافها وسياساتها المختلفة، فالتقدم في تخطيط وتنفيذ الطرق يعمل على تغيير نمط الحياة ورفع مستوى المعيشة ويساهم في تطور ونمو المجتمعات .تناولت هذه الدراسة البحث في موضوع عوامل ومعايير التصميم الهندسي للطرق ، وأستعرضت كلا من إعتبارات التصميم القديمة والعوامل المطورة لها ، والإعتبارات الأساسية الحديثة للتصميم، كما تطرقت إلى العناصر الأساسية والثانوية للتصميم الهندسي للطرق ، وقدمت لمحة عن مدى تأثير تصميم الطريق على سلامة المرور .وتم عمل مقارنة بين معايير التصميم الهندسي للطرق الحضرية مأخوذة من أربع أدلة تصميم مختلفة، والأدلة على التوالي هي :دليل التصميم الهندسي للطرق لولاية أريزونا الأمريكية ، ودليل التصميم الهندسي للطرق لجنوب أفريقيا ، ودليل التصميم الهندسي للطرق للسعودية، ومشروع إعداد دليل معايير التصاميم الهندسية لشبكة الطرق في ليبيا (الجزء الخاص بالطرق الحضرية) ، وأعطت تقييم عن المعايير المطبقة في ليبيا من خلال أمثلة لبعض مقاطع الطرق القائمة في مدينة طرابلس، كما ناقشت بعض المشاكل الناتجة عن عيوب معايير التصميم والتخطيط في المدينة ، وأهم ما قدم من مقترحات لمعالجتها .كما تم عمل دراسة تحليلية ( إستبيان ) كان الغرض منه التوصل إلى مجموعة من الأهداف وهي كالتالي:التعرف على نشاط الدولة الليبية في أعمال تصميم الطرق من عدمه .انطلاقا من أي مرجعية يتم تصميم الطرق في ليبيا ؟مدى اختلاف معايير التصميم باختلاف الفترات الزمنية التي تم فيها التصميم .مدى مواكبة معايير التصميم المستخدمة حالياً في ليبيا للتطور العمراني .مدى تأثير معايير التصميم على السلامة العامة لكل من الركاب والمشاة والبيئة .وختاما وبإستخدام كلا من النتائج المستخلصة من مراجعة مسودة مشروع إعداد دليل معايير التصاميم الهندسية لشبكة الطرق في ليبيا والمقارنة التي تمت بينها- المسودة – وبين الأدلة الأخرى، والنتائج المستخلصة من مراجعة مسودة مشروع إعداد دليل معايير التصاميم الهندسية لشبكة الطرق في ليبيا ومطابقتها للنتائج المتحصل عليها من الدراسة التحليلية (الاستبيان) ، خلُصت الدراسة إلى إستنتاجات وتوصيات يُرى أنها جديرة بكل إهتمام . Abstract Roads constitute the backbone around which revolves the country's unity , growth and development .Undoubtedly the presence of a developed network of roads in the country enables it to achieve its objectives and different policies , progress in roads is conducive to changing the lifestyle , raising the standard of living and contributing to the development and growth of societies.This study researched the factors and engineering design standards for roads and reviewed both the old design considerations and developing factors and basic considerations for modern design, and also addressed the primary and secondary elements of geometric design of roads and provided an overview of the impact of road design on traffic safety. Acomparison was conducted of engineering design criteria for urban roads taken from four different design guides and are respectively: Engineering design manual for roads of the U.S. state of Arizona, Engineering design manual for roads of South Africa, Engineering design manual for roads of Saudi Arabia, The project for preparing a manual of standards of engineering designs for the roads network in Libya (the section on urban roads). The study gave an assessment of the criteria applied in Libya through the examples of some sections of existing roads in the city of Tripoli, also discussed some of the problems resulting from defects in design standards and planning in the city and most important submitted proposals to address such defects.An analytical study ( questionnaire) was designed to reach the following set of goals:Identification of Libya State activity in the works of road design.What is the reference of road design in Libya?Variation of design standards for different time periods in which the design was developed.To what extent are the design criteria – currently used in Libya – are in pace with urban development?Extent of impact of design criteria on public safety for passengers,pedestrians and the environment.In conclusion, by applying the results extracted from reviewing the draft of the project for preparing the manual of criteria of engineering designs for the roads network in Libya and the conducted comparison between this draft and the other evidence and the extracted results from reviewing the draft of the project for preparing the manual of criteria of engineering designs for the roads network in Libya and the subsequent matching of the results obtained from the analytical study (questionnaire), the study reached conclusions and recommendations it deems worthwhile of due attention.
هالة محمد دحيم (2012)

Abstract The ever-growing numbers of people and vehicles seen by the Libyan cities at the present time, and the consequent increase economic and social development was held after the last incumbent to think of future supply in the system of road network in Tripoli after a decade or several decades to respond to the request and in particular the urgent need for radical solutions to all problems of congestion and bottlenecks and traffic accidents that were not the same size, severity and loss of physical and moral than ever before. This study addressed the focus of transportation planning, transport and highlighted the various stages of transport planning and reviewed the most important models used to predict the future traffic volumes, a resurgence or trip generation, trip distribution, mode of choice and traffic Assignment, where the focus of this study the first type of models which trip generation in the study area in Tripoli. And has been a review of some international studies in this area in both the United States of America, China, Korea, Iran, Nigeria, Egypt, Saudi Arabia, the focus in these studies to examine the variables affecting the creation of trips, the so-called independent variables affecting a number of family members and the number of vehicles and number of employees and income, the same factors that have been taken into account in the study area in Tripoli. Were identified the study area within the Centre for the city of Tripoli Commercial (CBD) called green belt area and specifically (range locality Martyrs coast and Aleneuvliyn), which recently experienced jams unprecedented, was the use of both methods for regression analysis to create a mathematical model is calculated both (Average trips, vehicle trips, and work trips) and Cross Classification Analysis to find work trips of the classification (number of vehicles / household size) and finding vehicle trips from category (the number of employees / income). Data were collected and information on the ground and through the questionnaire prepared by families in the region through the use of home Meetups and interviews necessary for the formation of mathematical models for the study and were compared with the results of both methods as used was to highlight the most important software modern and universally used in the travel demand. The study concluded the adoption of two models of regression to find trips generated, the first to find the average trips and the second vehicle trips The model work trips, he was excluded for being unfit, the Statistical The comparison higher efficiency of the regression model vehicle trips than cross classification analysis table to find the estimated values in generated trip, as a set of recommendations aimed at reducing the obstacles and difficulties in finding and the formation of specialized models to calculate the demand for mobility in cities of Libya
أمل فتح الله زايد (2010)

Two-stage concrete (TSC) is a special type of concrete that themethod of its construction and implementation is different fromconventional one. In TSC, coarse aggregate particles are first placed in the formwork and voids between themare subsequently injected with a special cementations mixture. TSC has been successfully used in many applications, such as underwater construction, casting concrete sections congested with reinforcement and concrete repair. Coarse aggregate forms about 60% of the total volume of TSC, while coarse aggregate forms about 40% of the total volume of conventional concrete. In TSC stresses are transferred through contact areas between coarse aggregate particles. In this paper coarse aggregate size influence on strength parameters of TSC and comparing it with conventional concrete is done (by uniaxial compressive strength test and Brazilian tensile strength test). According to results of tests in this paper, the TSC with finest grain of coarse aggregate has higher compressive and tensile strength, higher modulus of elasticity and less Poisson’s ratio from conventional concrete. arabic 11 English 66
Hakim Salem Abdelgader Abdelgader (3-2019)