Dynamic Response And Parameter Analysis Of Pavement Under Static And Dynamic Load

With the development of society,overloading vehicles and heavy-duty vehicles increase day by day,causing many serious damage to the road surface,thus affecting the driving safety and comfort and so on.In order to study the causes of pavement damage caused by overloaded vehicles and heavy-duty vehicles,it is very important to study the dynamic response of pavement under heavy loads.In this paper,hundreds of conventional roads have been investigated and four typical pavement structures have been selected.Typical pavement structure 1: 18 cm cement concrete slab surface layer + 18 cm lime soil base layer + soil foundation;typical pavement structure 2: 22 cm cement concrete slab surface layer + 22 cm cement stabilized macadam base layer + 18 cm lime soil base layer + soil base;typical pavement structure 3: 5cm asphalt concrete surface layer + 22 cm cement stabilized macadam base layer + 18 cm lime soil base layer + soil base;typical pavement structure 4: 3cm asphalt concrete surface layer+ 18 cm lime soil + soil base.According to each pavement structure,the corresponding experimental section is paved,and the five-stage loading method in the original highway engineering specification is added to the two-stage load with a total of seven loads to simulate heavy-duty and overloaded vehicles.The static load board test and the drop weight deflection instrument(FWD)impact load were carried out for the four typical pavement structures.According to the measured static deflection value and dynamic deflection value,the curve of the deflection basin is drawn.And the conversion relationship between the dynamic and static deflection values of each pavement structure under the full-scale load is established.It is found through the test that the relationship has a high correlation.Using the measured static deflection value to calculate the static rebound modulus of the top surface of the road surface;then using the Python language to compile the dynamic structure of each structural layer,and calculate the four kinds of pavements through the inverse calculation program and the measured dynamic deflection basin.Compared with the deflection basin obtained by two different loading methods,it is found that in the vertical direction,the static load deflection basin under the four pavement structures is much deeper than the deflection sink under the impact load,and as the load increases,the depth difference of the deflection value at the loading point is still gradually increasing;while in the horizontal direction,the static load deflection values of the four pavement structures are greatly reduced at 30 cm,while the deflection of the dynamic load shows more high level of communication ability.And through the comparison of the dynamic deflection values of the same surface pavement structure,it is found that the vertical propagation capacity of the impact load of the asphalt concrete surface layer is higher than that of the cement concrete board surface layer.Dynamic modulus of each structural layer under different loads.Comparing the dynamic and static rebound modulus,the conversion relationship between the static top surface comprehensive rebound modulus and the dynamic rebound modulus is established,and the fitting degree and significance of the relation are verified.The static top surface synthesis is found.The rebound modulus and the dynamic modulus of each structural layer show a high correlation.