Study On The Overall Design System Of The Highway

In recent years, especially after the international financial crisis in2008, the scale ofexpressway construction in China is undergoing an increasing expansion with the sustainabledevelopment of modern society and highway transportation industry. The expressways atdifferent provinces extend gradually from plains to mountain area. The topography andgeological conditions are becoming more and more complicated. Therefore, there are moretechnical problems need to be solved.The guiding ideology and design philosophy of general design of expressway at plainand hilly area were analyzed systematically at first. The contents of general design system ofexpressway were illustrated, including route scheme, embankment height and land resourcesprotection, bridge general design, tunnel general design, general design of interoperable gradeseparation design, traffic engineering, general design of ancillary facilities, landscape designand environmental protection design, etc.. The design standard and technical index of generaldesign for expressway was put forward.For the expressway at mountainous area, the emphasis of general design is tunnel generaldesign. The concept of administrative zones, the partition in the hole, hole administrative zone,traffic flow organization were analyzed. The concept of tunnel environment design isproposed. According to the analysis of the contents of positioning of the highway tunnel,tunnel location selection, plane linear design and profile design, the general design method ofmountain tunnel, cross-mountain tunnel and mountainside tunnel. The requirements ofselection of hole location were recommended.The thesis was set in the engineering of Guiping to Laibin expressway in Guangxiprovince. According to the comparative analysis between high embankment and lowembankment, channel combination plan and overpass combination plan, it was suggested thatdemonstration of engineering investment, land use, environmental coordination, reliability,security, construction period and operation period of the social influence for differentengineering should be conducted the topography, geology, road network in different parts ofthe water system, degree of difficulty of land resources. Expressway in mountain areainvolves in more selected factors. Therefore, the plan should be demonstratedomni-directionally, and the cost factor, ecological environment protection, the naturallandscape elements, the disaster and disaster prevention and human environment should alsobe considered. In the combination with engineering case analysis, the concepts of “classcontrol points”,“class control points” and "green full of mountains" were put forward. Theidea of “handling the sensitive environment” was also suggested. These design thinking and ideaswhich are different from previous are expected to improve the expressway survey and design work underthe similar conditions.