Research Of Pavement Roughness Evaluation Method Based On The Weighted Longitudinal Profile

Pavement roughness is one of the important indexes for evaluation of pavement performance. An excellent road surface would contribute to the vehicle ride comfort, reduce the damage to road structure and impact on the vehicle by tire dynamic load. Almost all the current used road roughness evaluation methods only reflect the pavement service performance level and the development trend of the roughness over time, and they do not retain the actual detailed contents of profiles. These evaluation indexes are only general summaries of a certain length sections with certain limitation. Based on this consideration, the Weighted Longitudinal Profile (WLP) is applied in this paper to give a more objective and accurate evaluation on the pavement roughness.First of all, embarking from the analysis method of the road surface wave, an artificial standard road profile was built by using inverse Fourier transform. It is effective to avoid the complex process of measuring the actual pavement roughness, meanwhile provide the basic data for the simulation of vehicle ride comfort and the evaluation on the road surface roughness.Then, CarSim/TruckSim software was utilized to simulate the vehicle ride comfort, and the variation tendency of various working conditions were analyzed. The simulation results indicate that:pavement roughness level, driving speed, and vehicle type are the important factors influencing the vehicle-road interaction. Vehicle ride comfort significantly decreased with declining levels of road pavement and increasing vehicle speed. Different factors that affect total weighted acceleration root-mean-square (aw) to the importance of the order from large to small is:the road pavement roughness level→driving speed→ vehicle type.Subsequently, the calculating formula of the Weighted Longitudinal Profile (WLP) evaluation index σw was deduced. Based on the research of the roughness index standard in Germany, the permissible values of σw were formulated, which were respectively suitable for different stages of the pavement design, construction and maintenance in our country. This index was used to make quantitative evaluation for the standard pavement roughness. The correctness of the WLP evaluation index σw was verified through comparing with simulation results aw in CarSim/TruckSim.Lastly, the WLP evaluation index σw and σw were used to evaluate pavement roughness data resulting from the actual engineering projects, and the evaluation results are consistent with existing ride quality index (RQI). The WLP evaluation method can be realized with the butt of the existing pavement maintenance system in our country. At the same time, the double control indexes of the Weighted Longitudinal Profile evaluation method can distinguish the different forms of roughness and locate the areas of bad pavement roughness more accurately, and contribute to decide the maintenance time of pavement roughness relatively quickly. It provides more reliable and stable evaluation criterion for road management in road maintenance management.In this paper, some problems existing in current pavement roughness evaluation methods are improved and the Weighted Longitudinal Profile (WLP) evaluation method proposed is more reasonable. The WLP evaluation index σw and σw are not influenced by the length of test section, the sample quantity and the vehicle speed. The vibration characteristics of human body and the vehicle are taken into account during the derivation of evaluation indexes. The Weighted Longitudinal Profile (WLP) evaluation method effectively makes up for the deficiency of the existing pavement roughness evaluation index in China and has a certain practical significance and theoretical value.