| In recent years,the state has further strengthened the efforts of road construction,but while promoting economic development and facilitating people’s travel,the construction process has also brought some environmental pollution,among which the diffusion of dust is an important aspect.In highway construction,the filling and digging of roadbed,the transportation of earth and stone,and the construction of engineering machinery will cause a great disturbance to the exposed soil source and road dust,which are the main influences of road construction on the surrounding air quality.In this paper,the characteristics of dust sources in construction areas are taken as the starting point to discuss the rules of their generation and diffusion,and provides direction and basis for the follow-up dust monitoring and dust suppression measures.By monitoring the composition of particulate matter from dust source,the change of moisture content and the disturbance and diffusion of actual construction vehicles,the law about the diffusion of the dust is obtained,and then the corresponding dust suppression device is designed for the disturbance dust of the construction transportation vehicle,and the actual dust suppression effect of the device is The relevant test verification was carried out and the following conclusions were obtained:(1)Through the screening test,the particle size composition of the common soil in Zhoukou area was obtained,and the composition characteristics of the dust source of the construction dust were analyzed to provide guidance for the follow-up dust suppression;(2)By testing the moisture evaporation rate of clay and sand at different temperatures,the law of the moisture content of the surface soil on the ground was obtained with time,and suggestions were made for the frequency of moisturizing and dust suppression measures at the construction site;(3)Through continuous observation of the dust diffusion of transportation vehicles at the highway construction site,the law of the diffusion of dust generated by vehicles at different speeds was discovered.Through the analysis of the test results,the occurrence,spread and influence range of the dust from highway construction were studied;(4)Building a laboratory for simulating construction dust generation and a verification platform for the dust suppression effect of spray devices.Through a large number of experimental studies in the built laboratory,different types of nozzles suitable for suppressing ground dust sources and diffused dust have been determined;(5)Designed a dust suppression spray system that can be installed on transport vehicles,and conducted a test study on the actual effect of the vehicle during the driving process at the construction site.It was found that the spray system has a suppression efficiency of about 67%on PM10 on paved roads,and PM2.5 The suppression efficiency of 50%-70%;when driving on a roadbed with a surface water content of about 6.5%,the system’s suppression efficiency for both PM2.5 and PM10 is about 40% when the vehicle speed is not greater than 20km/h;(6)Based on a large number of observations and tests on the construction site,on the roadbed with surface soil moisture content less than 10%,the dust generated by construction vehicles when the driving speed is greater than 30km/h is very serious;the driving speed exceeds 40 km on the paved construction road /h,a large amount of dust will also be generated;therefore,it is recommended that to control construction dust,the speed of construction vehicles on the roadbed should be controlled within 30km/h,and watering measures should be taken to make the surface moisture content not less than 10%.The driving speed on the paved construction road should be controlled within 40km/h. |
