Situational Route Selection Method Of Expressway In Ecologically Fragile And Geologically Complex Mountainous Areas

With the development of Chniese economic,improvement of people’s living and the whole improvement of science and techniques,the construction of high way in China is going deep into mountainous areas with backward economy,steep terrain,fragile ecology and complex geology.The quality of lines selection directly determines the construction expense,project quality and operation safety and efficiency of the project.However,in the mountainous area with complex geology and fragile ecology,the complex and coupled factors affecting the line selection are nested and restricted one aother,which makes it unable to effectively solve the problems in the known concepts of terrain,geological,ecological and environmental protection route selection.Therefore,based on my practical summary of my job in construction projects,I explore a kind of targeted,adaptable and flexible route selection method--situational route selection.The main research contents and achievements are as follows:(1)The concept,principle and basic steps of situational line selection are introduced.Situational route selection refers to the dynamic focus on key factors in a complex environment in a certain time and space,comprehensive analysis of the relationship between internal factors and external factors of the road system,and the implementation of comprehensive optimization of schemes dominated by key factors.This method focuses on multiple factors at the same time to carry out comprehensive,dynamic,flexible and in-depth comparison of different levels of schemes.(2)This paper analyzes and introduces the situation of engineering projects using situational route selection method.It also introduces topographic conditions,hydrological conditions and bad geological conditions of Shangri-La section of Ningxiang Expressway,drawing the geological structure map,hydrogeological map and distribution map of sensitive points for the overall characteristics of the area.(3)This paper introduces the principles,ideas and results of the selection of situational corridor belt in the case area.According to the characteristics of the section being studied,combining with the characteristics and selection principles of the corridor belt,the situation selection of the cross the ridge corridor belt and along the river corridor belt were respectively carried out.(4)The idea,principle,method and achievement of situational alignment in case area are introduced.This paper discusses how to realize the coordination and unity of line position,structure and environment in the process of route selection and complete the design of all route schemes under potential vision.The method proposed in the paper successfully solved the problems in the route scheme of the studied case,completed the establishment of the feasible study report,and passed the national approval.This method can be used for reference in projects with similar engineering background.