道桥专业英语省公开课一等奖全国示范课微课金奖PPT课件.pptx

道路与桥梁工程专业英语第一讲绪论第一讲绪论第一讲绪论第一讲第一讲绪论第一讲绪论第一讲绪论第一讲绪论第一讲绪论第一讲绪论第一讲绪论第一讲绪论第一讲绪论Highwayengineeringisanengineeringdisciplinebranchingfromcivilengineeringwhichinvolvesthedesign,constructionandmaintenanceofhighwaysystems.Highwayengineeringbecameprominenttowardsthelatterhalfofthe20thCenturyafterWorldWar2.Standardsofhighwayengineeringarecontinuouslybeingimproved.Highwayengineersmusttakeintoaccountfuturetrafficflows,designofhighwayintersections/interchanges,geometricalignmentanddesign,highwaypavementmaterialsanddesign,structuraldesignofpavementthickness,andpavementmaintenance.Mostdevelopednationshaveextensivehighwaynetworks.Themostappropriatelocation,alignment,andshapeofahighwayareselectedduringthedesignstage.Highwaydesigninvolvestheconsiderationofthreemajorfactors(human,vehicular,androadway)andhowthesefactorsinteracttoprovideasafehighway.Humanfactorsincludereactiontimeforbrakingandsteering,visualacuityfortrafficsignsandsignals,andcar-followingbehavior.Vehicleconsiderationsincludevehiclesizeanddynamicsthatareessentialfordetermininglanewidthandmaximumslopes,andfortheselectionofdesignvehicles.Highwayengineersdesignroadgeometrytoensurestabilityofvehicleswhennegotiatingcurvesandgradesandtoprovideadequatesightdistancesforundertakingpassingmaneuversalongcurvesontwo-lane,two-wayroads.
vehicledynamics–汽车动力
lanewidth—车道宽度
maximumslopes——最大纵坡度
designvehicles——设计车辆
designvehicles——视距
two-lane,two-wayroads——双向双车道道路GeometricDesign
Highwayandtransportationengineersmustmeetmanysafety,service,andperformancestandardswhendesigninghighwaysforcertainsitetopography.Highwaygeometricdesignprimarilyreferstothevisibleelementsofthehighways.Highwayengineerswhodesignthegeometryofhighwaysmustalsoconsiderenvironmentalandsocialeffectsofthedesignonthesurroundinginfrastructure（基础设施）.
GeometricDesign
Therearecertainconsiderationsthatmustbeproperlyaddressedinthedesignprocesstosuccessfullyfitahighwaytoasite’stopographyandmaintainitssafety.SomeofthesedesignconsiderationsincludeDesignspeed,Designtrafficvolume,Numb