Research And Application Of Smoothness Grading Of Transportation Road In Open-pit Coal Mining Area

The transportation road of open-pit coal mine is an important part of the production system of open-pit coal mine,and the smoothness of road surface has the greatest influence on the service performance of pavement.With the increase of production capacity,transportation volume and large-scale mechanical equipment in large-scale open-pit coal mines,the damage to the smoothness of transportation roads is more obvious.At present,the existing grading standards of highway smoothness are not suitable for evaluating the smoothness of open-pit roads.In order to evaluate the smoothness level of open-pit roads,based on the relationship between transportation roads and vehicle fuel consumption in open-pit coal mines,the threshold range of IRI(international roughness index)is redefined through data collection,regression analysis and cluster analysis,as follows:(1)The reliability of airborne three-dimensional laser scanning system applied to surface roughness of open-pit coal mine is studied,and the theoretical accuracy of scanning instrument is demonstrated.With the help of airborne radar,the elevation data of transport vehicle trajectory line are effectively extracted.The calculation program of IRI value index is written in Python language,which can automatically calculate the obtained data.The influence of different statistical intervals of IRI value of transportation roads in open-pit coal mines,such as 10 m,20m,50 m,100m,150 m and 200 m,on the calculation results is explored.It is found that when the statistical interval exceeds 150 m,the overall smoothness of the road surface can be well reflected without losing details.(2)The linear relationship between IRI value data and fuel consumption data of mine transport vehicle trajectory is analyzed,and the fuel consumption law models of open-pit transport vehicles in different states of no-load and heavy load are explored.Based on K-means clustering algorithm,the oil consumption data are divided into three categories: "fuel saving,moderate consumption and oil consumption",and the IRI value grading threshold of transportation roads in open-pit coal mines is calculated.(3)Taking Harwusu open-pit coal mine as the engineering background,the new IRI value classification threshold is adopted to classify the transportation roads in the mining area;The fuel consumption cost is calculated based on the expression.After calculation,the part of the road evaluated as "poor" is trimmed to "medium" grade,which can save at least 4.1% fuel under heavy load and 2.7% fuel under no-load condition.It is verified that improving the smoothness of transportation roads in open-pit coal mines can greatly save fuel consumption costs and help improve the production efficiency of open-pit mines.