Study On The Method Of Measuring The Depth Of Pavement Structure In Real Time By Using Tire-road Noise

Pavement quality testing plays a more and more important role in Highway Maintenance Engineering,but more and more diseases and accidents show that it is difficult to keep up with the need of highway construction and maintenance by the existing speed of measurement of pavement.Although many projects have taken some measures to improve the tests,the results of the tests are still not consistent with the actual quality of the road sometimes.Due to the rapid development of road surface disease,the frequency and efficiency of road detection is too low,and the road surface data we refer is relatively backward,these make it difficult to predict the quality of pavement accurately and in real time.Pavement skid resistance is closely related to traffic safety and the texture depth is one of the important factors to characterize the anti sliding performance whose importance is self-evident The noise of the tire-pavement is accompanied by the running vehicle with the change of the depth of pavement texture from time to time.In order to improve the efficiency of road texture depth detection,it is necessary to collect the tire-pavement noise information and present the corresponding texture depth through the analysis instantaneously.So it is of great engineering significance to measure the depth of pavement structure to reflect the quality of the pavement.This paper first summarizes and analyzes the domestic and foreign methods,advantages and disadvantages of measuring the asphalt pavement structure depth;emphasizes the impact of various factors,tires and pavement,on the tire-pavement noise,in addition,analyzes the non-pavement factors' influence in brief;According to the analysis,it is found that due to the complex mechanism of tire factors and the various factors will influence together,through the design of the test with the same tire at different speeds,different road conditions to collect noise data information.Carry out the Fourier transform to process data through the MATLAB software,and use EXCEL software to normalize the data,and then select the first PC vector representing pavement characteristics using the principal component analysis.Import the new data into the MATLAB and present in the form of images.Through analysing the images of the first principal component vector,we can use it to forecast the pavement structure depth and verify it.The results of analysis and research are as follows:1.The traditional manual sanding method is applicable at home and abroad,vehicular laser structure depth meter method has become common,but the efficiency is low.Seen from the comparison with the United States,the United States has conducted research on the use of sound to measure noise,but it has not been a breakthrough.2.The main evaluation index of noise is A full of sound pressure level and 1/3 octave band spectrum.Sound pressure level and sound pressure,sound pressure and voltage can be converted to each other Tire-pavement noise mainly contains tire pattern noise and tire vibration noise.The tire vibration noise is not related to the texture characteristics of the road,and the noise related to the depth of the pavement structure is the pattern noise.3.Among the tire factors,the sound pressure level of tire with high anti sliding and wear resistance is larger.Patterns are key factors influencing the pavement noise and have the largest influence on the change range of SPL.There exists a critical trench depth,and the noise level at this depth reached the maximum.Increase or decrease the pressure based on the standard tire pressure,the peak pressure of tire-pavement noise is improved and the sound pressure level changes periodically with the increase of frequency.4.Among the pavement factors,the change of the tire pavement noise are different with different pavement structure and the difference is so large.The pavement void ratio has a great influence.The sound pressure level and void fraction are functioned with a equation: y=-0.5514x+86.898.The larger the porosity is,deeper the structural depth will be and lower the tire-pavement noise will become.5.Among the non road factors,speed has the largest effect on the tire-pavement noise.The noise increases with the increase of vehicle speed,but the range increasing is getting smaller and smaller,following the formula: y=35log(1+10/v).When traveling at high speed,the peak value of sound pressure level is near 1000 Hz.With the increase of the load,the noise of road surface increases first,but the range of the increase is gradually reduced,and then the noise will slowly decrease.With the increase of temperature,pavement noise decreases,but there is no regularity in different speed under test.The humidity of pavement has little influence on the general dense asphalt pavement,but for the porous pavement.6.According to the D-value ranking of the sound pressure level,it is found that tire factors have the greatest impact on the tire-pavemnt noise,the speed of the non-road factors is the second,and the road surface factors are the least.7.According to the theory of PCA,the first PC vector selected can be used as the representative of the road surface characteristics.And verified by experiments,the first PC vector is not affected by vehicle speed,and it can be used to measure the depth of pavement structure in real time,and the accuracy of measurement is very high.Conclusions and results obtained by the analysis in this paper can be used to improve the detection speed in practical application guaranting the quality of road detection,which has a great impetus to establish the nationwide road quality called”big data”.