A Study On The Preditction Of Noise With Chongqing Road Expressway Project And Measures Of Its Prevention And Control

Urban expressways/elevated roads are built as an effective means to reduce traffic congestion and increase transport capacity,as cities grow bigger and city roads become more crowded.The change of road types makes changes to the impact of traffic noise to the environment.This article is based on technical documents i.e.,Feasibility Study Report on Chongqing Road Expressway Project,Technical Guidelines for Noise Impact Assessment(HJ2.4-2009)and Environmental Quality Standard for Noise(GB3096-2008),as well as a series of site monitoring of acoustic environmental quality at noise-sensitive points along the Chongqing Road,together with the prediction of environmental impact before the project is completed.The study has explained the range and level of impact with traffic noise and proposed measures of its prevention and control.The outcomes are as follows:I.Acoustic Environmental Quality EvaluationThe part of Chongqing Road between the crossroads with Nanjing Road and the junction with Jinshui Road is distributed with shops like 4S stores,while residential quarters are far from the road.As there are many large vehicles travelling on this part,the value of noise is high.Eleven monitoring points were set up along this section and it turned out that day-time values collected from two sites exceeded the standard by more than 5dB,and evening values collected from seven sites exceeded the standard by more than 5dB,showing serious excess.The part from the junction with Jinshui Road to Qingdao Iron and Steel Group is next to the airport,with heavy traffic,large vehicles and ill maintained road structure.The noise level there is high.Eight monitoring points were set up along this part of road and it turned out that day-time values collected from two sites exceeded the standard by more than 5dB,and and evening values collected from from four sites exceeded the standard by more than 5d B,showing high value of excess too.The section from Qingdao Iron and Steel Group to Liuting Overpass has no sensitive points and the main factor to be monitored is traffic noise only.This section is the transport hub with heavy traffic.The result of monitoring shows that average day-time value collected exceeded the standard by less than 5dB,and evening values collected from two sites exceeded the standard by more than 5dB.II.Prediction of Noise Impact on EnvironmentalThe Chongqing Road Expressway Project is an urban road project combining elevated roads and ground level roads,in which traffic noise has different levels of impact according to the altitude.Most of the sensitive points' noise contribution values are up to the standard of their specific acoustic function zones,and the excess of noise value at sensitive points mainly take place in the evening.III.Measures to Prevent and Control Traffic Noise PollutionAccording to the actual situation of the Chongqing Road Expressway Project,sound insulation screens were applied at selected sections along the road to reduce the environmental impact by traffic noise.With sound insulation screens,monitoring results of some sensitive points can reach the standard of their specific acoustic function zones,while that of some sensitive points still exceeds the standard value during evenings.