پديد آورندگان :
وفائي نژاد، عليرضا دانشگاه شهيد بهشتي، دانشكده مهندسي عمران، آب و محيط زيست گروه مهندسي سازه و ژئوتكنيك , مرادي سلوشي، بهرام راه آهن جمهوري اسلامي ايران - گروه سيستمهاي اطالعات مكاني - دفتر آمار و فناوري اطالعات
كليدواژه :
سيستم اطلاعات مكاني , GIS , ظرفيت شبكه ريلي , پايگاه داده گراف , سرويس تحت وب
چكيده فارسي :
سيستم حمل‌ونقل ريلي از تعامل مجموعه‌اي از تجهيزات و عمليات تشكيل‌شده است كه توانايي و ظرفيت يك سيستم ريلي در حمل‌ونقل بار و مسافر را تعيين ميكند. بدين منظور محاسبه ظرفيت و تحليل نحوه تغييرات كليه عوامل مؤثر بر آن مهم و شناخت آن‌ها كمك شاياني در ارتقاء سطح بهره‌برداري شبكه ريلي دارد. روش‌هاي مختلفي براي محاسبه ظرفيت وجود دارد كه با توجه به نوع شبكه و نحوه استفاده از آن ميتوان از آن‌ها بهره گرفت كه در حال حاضر در كشور ايران، به دليل اينكه شبكه ريلي داراي تنوع استفاده به‌صورت باري، مسافري و يا تركيبي (باري و مسافري) است، از روش محاسبه ظرفيت راه‌آهن كه به رابطه ظرفيت عملي مشهور است (رابطه Scott) استفاده مي‌شود. در اين زمينه، هدف تحقيق حاضر كه براي اولين بار صورت مي‌پذيرد، اين است كه براي محاسبه ظرفيت از توانمندي‌هاي سيستم هاي اطلاعات مكاني بهره جسته و با طراحي و پياده‌سازي يك سيستم اطلاعات مكاني تحت وب، وضعيت ظرفيتي عملياتي شبكه ريلي را به صورتي نوين و با كارايي بيشتر نسبت به روش‌هاي متداول تعيين نمايد. بدين منظور محيطي GIS مبنا طراحي گرديد كه به پايگاه دادههاي مختلف شركت راه آهن جمهوري اسلامي ايران ازجمله پايگاه سير و حركت متصل شده و ضمن مشاهده وضعيت فعلي ظرفيتي شبكه، راهكارهايي براي استفاده از ظرفيت خالي، بالا بردن ظرفيت شبكه و همچنين رفع گلوگاه هاي ظرفيتي شبكه ريلي مطرح ميكند. استفاده از اين شيوه، نه‌تنها باعث افزايش سرعت و دقت محاسبه ظرفيت شبكه شد، بلكه باعث بهبود تصميم‌گيري مديريتي جهت استفاده از ظرفيت خالي شبكه به‌منظور فروش اين ظرفيت به شركت‌هاي متقاضي و كسب درآمد براي شركت راه‌آهن جمهوري اسلامي ايران نيز گرديد تا جايي كه قبل از شروع هر فصل يا سال، ميتوان قراردادهاي مناسبي براي تقاضاي صاحبان بار و مسافر در شبكه ريلي منعقد نمود.
چكيده لاتين :
Railway transportation system is composed of interactions among a set of equipment and operations determining the capability and capacity of the railway system in terms of cargo and passenger transportation. The structure of capacity in rail transport is different from that of other methods of transport and especially road transport. Parameters affecting the capacity of rail transport systems are very extensive, depending on type of route in terms of the route geometry and the technologies used in operation. The ability and capacity of carrying freight and passenger in a rail transport network is a function of various parameters in the path of the fleet such as route characteristics (slope, arc, electric signs system, speed limitations, tunnels, etc.), features of fleet (locomotive speed, weight, type of pulling force, type of wagons, etc.), features and characteristics of operations in stations (loading and unloading system and equipment of stations), type of operation and schedule of departure in the rail network (speed and type of trains), construction or reopening of stations, and tracking. All these factors define and determine the capacity of a rail transport system and the nodes for utilization of the network. For this purpose, capacity calculation and analysis of changes in any factor affecting it are important as the corresponding knowledge imposes large contributions in enhancing operating level of existing railway networks. There are various methods for calculating the capacity, of which one may select one depending on the network type and application. As of now, in Iran, considering the variety of applications planned for railway network (cargo, passenger transportation, or a mixed of the two), so-called practical capacity method (Scott’s formula) is used to calculate line capacity. Accordingly, current procedures followed in data gathering and obtaining effective parameters on line capacity calculation, as well as actual capacity calculation and analysis are performed manually, resulting in some discrepancies in different calculations and results. Further, there are chances that, planning based on an inappropriate estimation of line capacity, a portion of actual line capacity remains unused. As such, the present research, which is the first on the topic, aims at using capabilities of geographic information system (GIS) to design and implement a web-based GIS service to determine the state of railway network capacity via a novel approach which offers higher efficiency than conventional methods. For this purpose, a base GIS environment was designed and connected to different databases run by Islamic Republic Of Iran Railways Co., including the travel database, to observe current state of the network in terms of capacity and propose solutions to further exploit unused capacity of the network and address bottle-necks of railway network capacity usage. The use of this method not only resulted in enhanced pace and accuracy of network capacity calculations, but also brought about better managerial decision-making to use unused capacity of the network and sell this capacity to applicant companies and generate further revenue for Islamic Republic Of Iran Railways Co., to the extent that, prior to any new season or year, one could sign appropriate contracts to address the demand raised by cargo owners and passengers across the railway network.
