Study On The Distribution Law Of High-rise Vertical Traffic Noise From Urban Perspective

The noise problem is a pollution problem that is facing the world.Traffic noise,as the main source of noise in the city,endangers people's physical and mental health and normal life.With the continuous development of cities,most modern cities are characterized by high density and high volume ratio.The problem of noise pollution is no longer limited to two-dimensional planes.The residents living in high-rise residential buildings are also deeply affected,and the vertical noise problem becomes social hotspot.However,there are different high-level noise studies in the city or focus on the plane space,or only consider the impact of the current road,the conclusion of the vertical noise distribution is different.Therefore,this paper studies vertical traffic noise from the perspective of the city,in order to clarify the vertical noise impact mechanism,explore the internal laws,and unify existing research.First of all,this paper selects two typical urban forms in the city for vertical noise measurement and analyzes the vertical noise law.The city sample 1 is mainly affected by the current road,and the sample 2 is affected by the distant road network.It was found that the vertical noise law showed “first increase,then decrease and then increase”,but it was different.It is proved that different urban forms will affect the vertical noise distribution.Further,the theoretical model verification hypothesis is established,that is,the vertical noise law is formed by the interaction between the road space distance and the visible area.Taking a single road influence as a theoretical model,the simulated values of vertical noise and spatial distance under different road distances are obtained,and the effective road visibility is obtained through the analysis of the main road segments contributing to noise.The spatial distance and the visible area are used as independent variables,and the partial correlation analysis is performed with the sound pressure level of each layer as the dependent variable.The spatial distance is negatively correlated with noise,and the visible area is positively correlated with noise.It is proved that with the increase of altitude,the spatial distance and the visible area of the road interact with each other,and the change of the noise in different situations causes the noise law to “first increase,then decrease and then increase”.Finally,the vertical noise of typical urban form is classified and quantified.Three urban indicators affecting vertical noise are selected: road distance,road grade and volume ratio.The city is divided into 48 typical forms,and the model is calibrated and modified on the basis of measured samples.On the one hand,the analysis of noise difference(the necessity of judging vertical noise analysis),noise change trend(the impact on low,middle and high buildings)and maximum noise floor: when building < 11 floors,or adjacent sub-trunk roads,or road distance > 200 m,it is not necessary to consider the vertical change of noise.The higher the road grade,the nearer the distance,the lower the surrounding volume ratio,the greater the noise difference,the more important it is.Concern about the trend of noise;the higher the grade of road,the closer the distance,the lower the volume ratio,the stronger the growth trend of noise in the lower floor,and the stronger the growth trend of the higher floor;the most significant impact on the maximum noise floor is the road distance,when the road distance is 20 m,the maximum noise floor is 3-5 floors,and the farther the distance,the maximum noise floor appears in the middle floor or above 30 floors.On the other hand,according to the characteristics of the trend of vertical noise,the first level of sound pressure is used to normalize the vertical noise,obtain the relative changes,and make regression analysis to obtain the prediction model of the trend of vertical noise in typical cities.The research proves that urban morphology affects the vertical noise distribution,and the vertical noise presents the trend of "increasing first,then decreasing and then increasing",which improves the research of vertical noise from the urban perspective.The influence mechanism of vertical noise is defined,which is affected by the interaction of space distance and road visual area.Through theoretical verification,quantitative analysis of typical urban morphology,and finally provide a simple vertical noise prediction model,so that people can identify the surrounding urban morphology,get the trend of vertical noise,seek advantages and avoid disadvantages.