Studies On Road Surface Vibration Frequency Based On Vehicle-road Coupling Vibration System

The existing design specification of cement concrete pavement does not consider the influence of vehicle-road coupling vibration. After investigation, among the type of damage,in addition to void under slab and flexural fatigue induced by plastic deformation of the roadbed and pumping damage. There is another failure mode which is shock vibration damage caused by the pavement roughness.The current pavement roughness evaluation is summary and cursory, the study on the free vibration frequency characteristics of the road surface under the vehicle load is not deep. Therefore, through theoretical analysis and finite element simulation, the paper establishes evaluation indexes of pavement level and launches quantitative analysis; when pavement level less than C, the intense vehicle-road vibration is induced by road roughness which effects comfort level and the pavement fatigue damage,proposes a technical mean to reduce the vibration amplitude by optimizing the structural parameters and a method to calculate dynamic modulus of earth subgrade based on the vibration frequency of road surface. The experimental study of vibration response is carried out on different cement concrete surface layer. These study results have a certain reference value for the design, research and test of long-life pavement. Specific contents are as follows:1?Solution of vehicle random load and frequency analysisBuilding a MATLAB program to simulate the process of vehicle driving on uneven pavement surface, which simplifies the solving process of vehicle random load and vehicle body acceleration, The power spectral density of vehicle random load is calculated in order to get the main frequency, and the influence of different factors on the power spectral density is discussed by control variate method.2?Establishment of the pavement roughness evaluation indexes and quantitative analysisThe pavement roughness evaluation is summary and cursory in china, this paper chooses root mean square value of vehicle body acceleration, dynamic amplification factor and bumping probability as evaluation indexes, analyzes quantitatively the change rule of evaluation indexes on different pavement level.3?Studding road surface vibration frequency based on vehicle-road coupling vibrationCarrying out a detailed investigation on representative cement concrete pavement layerparameters to determine design parameters variation range of recent domestic pavement; By numerical simulation of pavement under vehicle loads,this paper sums up the variation of road vibration response under different surface layer, the base layer, subgrade parameters and road roughness, the speed.4?Calculation method of dynamic modulus of subgrade based on vibration frequency of cement concrete pavementA new calculation method of dynamic modulus of subgrade is put forward,which bases on the vibration frequency measured under shock load.5?The vibration response study of cement concrete surface structure layerIn order to study the vibration response of different cement concrete surface layer structural parameters, the experimental study of vibration response is carried out on different cement concrete surface layer.