Study On Characteristics And Quantification Of Road Alignment

The road in gardens not only carries the traffic function,but also is an important landscape element that constitutes the landscape,links the scenic spots and organizes the vision.The "stepby-step landscape" in traditional gardens is the best interpretation of the function of road landscape composition.Road is an integral part of the bottom interface of landscape space.Through the combination of plane and vertical changes,people can be guided to travel and get a dynamic perception of the landscape environment.Landscape road alignment refers to the twists and turns of road in plane and vertical direction.The emphasis of alignment design is to determine the most suitable horizontal twists and vertical fluctuations of road based on road alignment selection.Road alignment determines the form of road in space,and then affects the nature of the landscape,but also determines the pedestrians’ viewing of other landscape elements on the path of the park.Continuously changing roads create diverse perspectives by guiding the viewer to change the direction and height of the line of sight.From the perspective of external factors,the design of road alignment is affected by landscape environment and functional requirements.Moreover,the design site scale,shape,topographic changes,visitor behavior and many other factors will also have a certain impact on the design of road alignment.As far as the construction cost of the road is concerned,through the quantitative analysis of a large number of excellent cases,the composition law of the road alignment can be concluded.In view of this,on the basis of classifying and discussing these influencing factors,this paper synthetically analyses the factors influencing the road alignment composition,and finds out the characteristics of road alignment in plane and vertical direction,and then constructs quantitative indicators with guiding value for the landscape road alignment design.For road plane alignment,the quantitative indexes of frequency,amplitude and distance of turning point are selected for quantitative control;for vertical change of road,the indexes of frequency,gradient and distance of vertical turning point are selected for quantitative control.In this paper,36 representative excellent road alignment design cases are selected.By studying the data of road plane and vertical alignment,the index intervals which can regulate and control road alignment are summarized,and then the design of road alignment is guided more pertinently.Combining with the environmental renovation scheme design of Qinhuai River and Hetou area outside Qinhuai District of Nanjing,the application of relevant methods in road alignment design is discussed in detail.Research on the common characteristics of excellent road design cases under quantitative indicators can summarize the regularity of road alignment change in plane,vertical and space,and provide more accurate guidance for road alignment design practice so as to ensure traffic safety,comfort and sightseeing experience in tourism.