The Selection Of The Railway Line And Controlling Factors Of Geology For New Line Of Guang Nan Yun Gui

Distribution of carbonate rocks in China are very wide area, especially in the regions of southwest, including Yunnan, Guizhou, Sichuan, Chongqing and Hunan, Hubei, Guangxi, because of the strong karst, lines of communication building are largely restricted by the complex geological environment and geologic conditions and the complexity of karst controls the direction of the traffic distribution routes.The new railway line of Yun-Gui is east from Nanning in Guangxi Province to Kunming in Yunnan Province, and Yunnan Province length is 396.15km, Guang Nan section– from Zhu Lin county to Banbu township board within the route of mussels 107.15km. The Guang Nan section with the most complex geological structure and strong karst development makes it the most representative of the typical karst mountain in the entire study area, distribution of the railway line in this area iscontrolled by the geologic conditions, so this paper takes the Guang Nan section for study, analysis of the railway line in the area of the control scheme selection and geological factors.This thesis research content and results are as follows:(1) The study of geological conditions of the study to understand Yunan-Guangxi Railway Guang Nan section are eastern Yunnan karst plateau landscape area, the plateau landscape from the hills, low medium mountain and plateau basin and dissolution of the original composition, topography dramatic, mountain majestic, mountain ranges; the construction system is located in the complex position western section of Nanling large zonal structural structure and Yunnan and Vietnam giant knob tectonic system, changing structural features, changing structural features, faults and folds are well developed; the complexity of the control structure formation, lithology distribution, distribution of soluble rock strata within the region is extremely broad.(2) By comprehensive understanding the regional geological background, geomorphological features, structural framework, in the existing of fold system Qiubei - Guang Nan fold beam and Wenshan - Funing fold beam, carefully divided into regional tectonic system, was divided into five geological units, and to analyze the complexity of geological structures for ground water systems provide the basis for the division.(3) Survey of karst development in study area, through the distribution of the regional characteristics of soluble rock, distribution, combined features; the characteristics of karst in surface and underground; the karst development level of the investigation, obtained a very strong area of karst development, karst development on the right bank of Xiyang river is most strong.(4) investigation of the regional hydrogeological conditions, identify the various types of water distribution and Fu rock group water, groundwater genetic type, occurrence conditions; groundwater recharge, runoff and discharge characteristics, delineation of groundwater enrichment block; Identify the general rules and karst spring point, the distribution of underground river, combined with the characteristics of tectonic division of the six water system, analysis of the complement system of karst water runoff and discharge and the degree of karst development.(5) Three feasibility programs are preliminarily selected: the paper analysis engineering geological problems of the various programs encountered, analysis the feasibility of segment of a length of the program in different water systems detaily and compare the three programs, process to avoid the poor geological area and strong regional karst areas.Through comparative analysis,part of the journey in option I and option II is the feasibility the program segment. As the geological conditions across the region are too complex and would have been a variety of karst disaster, option III is denied. The paper work out a reasonable optimization according to Programme I and Programme II.(6) Optimization of the railway scheme can not completely avoid the hydrogeology problems.Relying on karst water system in the region the paper analys the the major engineering problems of optimization of the railway scheme, there is a high risk of the tunnel (Xiaozhai Tunnel) in the lines, the rest are mostly low-risk tunnels. The study provide a basis and guidance for the safety problems in the future railway construction and reducing operating costs.(7) Based on the above analysis, extracted the the geological factors controlling factors in Guang Nan section of Yunnan - Guangxi Railway route selection, were terrain factors, formation lithology, geological structure and groundwater on the activities of factors,factors including lithology and groundwater activities of the alignment process in this area is the main controlling factor.