交通运输英语ppt课件

1、Highway LocationOutline1、The definition and basic principle ofHighway Location2、The highway location process3、Impacts of Highway Construction on theEnvironment and Economic4、The methods of highway location5、Conclusions1、Definition: Its a process that within the scope of “roadband(orcalled alignment

2、corridor)selected in the line selectinglayout stage, according to the settled technical standards,combining the datailed topography, geology and othernatural conditions and considering the reasonablearrangements of the flat, vertical and horizontal sides,the engineer set the exact location of the ce

3、nter line ofroad. 1、Principle: Roadway elements such as curvature and grade mustblend with each other to produce a system that providesfor the easy flow of traffic at the design capacity,whilemeeting design criteria and safety standards.2、The highway location process(1)Office study of exsiting infor

4、mation(2)Reconnaissance survey(3)Preliminary locate survey(4)Final location survey1The first phase of HighwayLocation(Office study of exsiting information)A、DefinitionB、The sources of the dataC、The types of the dataD、The preliminary analysis of the data2Reconnaissance surveyThe object of this phase

5、is to identy several feasibleroutes,each within a band of a limited width of a fewhunderd feet. 插图 Feasible routes are inentified by a stereosopicexamination of the aerial photographs. Control points between the two endpoints are determined for each feasible route. 3Preliminary location survey Estab

6、lishing all the control points; Determing preliminaryvertical and horizontal alignments. Preliminary alignments are used to evalute the economicand environmental feasibility of the alternative routes. 4Final Location SurveyA、Determining the horozontal and vertical alignments.B、Locating the positions of structures and drainage channels. ToolsA、SplinesB、Curve templates3、Impacts of Highway Construction on theEnvironment and EconomicA、Environment B、Economic4