Research On The Capacity Expansion Revamping Scheme Of Gela Segment Of Qinghai-Tibet Railway

In the past ten years, Gela Segment of Qinghai-Tibet Railway plays an important role in improving the transportation system of Tibet, promoting economic and social sustainable development, strengthening national unity, consolidating the southwest border and safeguarding national interest. At present, the transport capability of Gela Segment is almost near saturation, which cannot meet the requirements of Tibet economic development. Therefore, it is extremely urgent to expand the capacity of Gela Segment scientifically and reasonably. However, the lack of relevant researches on capacity expansion revamping about railway in frigid zones. This paper tries to carry out research in this filed. The main research contents are as follows:(1) Summarize the theory about improving the transport capacity of railway and design the Gela Segment’s capacity expansion scheme. This study summarizes the theory about railway transport concept, calculation and strengthening. Then, this study analyzes the current condition of Gela Segment, predicts the transportation demands, sets up the basic principles of capacity expansion, analyzes the applicability of capacity expansion revamping measures for single-track railway, and proposes two schemes, including automatic block and building double-track railway in some sections step by step, which provides supporting conditions for later research.(2) Automatic block capacity expansion revamping scheme. Based on the analysis of working diagram features of Gela Segment, we proposed the model algorithm as below. Based on the framework of the passenger trains, the number of freight train paths can be determined. Considering the section with least paths as the limited section and the deduction caused by train path expansion and windows, the carrying capacity of Gela Segment can be determined. This study aims at maximizing train paths of freight train with the integer programming model constrained with the scheduling principles and the model is solved by LINGO.(3) The capacity expansion revamping scheme of building double-track railway in some of the sections by stages. This scheme based on periodic timetable of single and double track section, especially for the double track section and the "double-track unit" and "calculating section" concepts are proposed. After analyzing double-track unit period of different types, calculating rules of double-track unit period can be derived so as to establish period calculating methods of periodic timetable in partially double-track sections, which can be worked out by using object-oriented language C#. Then carrying capacity for Gela Segment is calculated with untracking and tracking running diagrams under different double-track rate, which provides the theoretical basis for capacity expansion by building double-track by stages in some sections of Gela Segment.