Simulation Of Dust Diffusion In Highway Mechanized Construction And Study On Dust Suppression Measures

Highway traffic construction makes people travel more convenient,but at the same time in the process of highway construction transportation vehicles and mechanical equipment operation will produce a certain amount of dust pollution,which has a negative impact on the atmosphere environment,human health,plant growth and other aspects.In order to effectively control the dust in highway construction,it is necessary to deeply study the law of dust generation and diffusion.In this thesis,the material composition and characteristics of highway construction dust were studied to distinguish it from other particulate pollution in the atmosphere.The particle size distribution was studied through sampling test of soil that is easy to generate dust at the construction site,which provides a basis for setting parameters such as particle size of dust particles in the simulation of construction dust diffusion.Secondly,simulation software is used to simulate the dust diffusion caused by engineering transport vehicles in the process of highway construction under different conditions,as well as the construction dust diffusion caused by local construction site in the presence of barriers and different heights of barriers.Finally,the indoor and outdoor construction dust observation test was designed to verify the simulation results,and combined with the simulation and test results,specific suggestions were put forward to control the construction dust,and the following results were obtained:(1)Based on the analysis of particle size distribution of soil sampling at the construction site,it is concluded that the particle size of local soil samples mainly ranges from 10 to 100μm,and the median particle size distribution values of the two kinds of soil samples are respectively46.58μm and 25.81μm,which provides a basis for the setting of simulation parameters.(2)The diffusion of dust particles caused by engineering transport vehicles on the construction walkway was simulated in the simulation software.The results showed that the wind speed and the amount of dust that could be raised on the road had a great influence on the generation and diffusion of dust.Combined with the field test,it was concluded that the construction should be stopped when the wind speed on the construction site was higher than8m/s,and in order to control the amount of dust that could be raised on the road,the surface moisture content should be maintained at 5%～10%.It is recommended that the speed of engineering vehicles should not exceed 40km/h,and the main influence area of dust should not exceed 120 m.(3)The diffusion of construction dust generated by local construction on site was simulated in the simulation software.The results show that the enclosure can effectively control the diffusion range of dust,and the higher the height of the enclosure,the better the dust suppression effect,the dust suppression effect of 3m can reach 90%,and the dust suppression effect of 2.2m can reach 80%.In order to ensure the dust suppression effect,the height of the construction site is recommended to be no less than 2m.(4)Combined with the simulation and test results,it is concluded that the key point of controlling highway construction dust is to control the amount of dust that can be raised from the source.If the amount of dust raised from the construction dust is too large,water mist dust removal measures and high containment can not effectively reduce and control the dust diffusion.