Study On Vehicle-Road Interaction And The Effect Of Cracks In Cement Concrete Pavement By Vehicle-Road Interaction

For the property of high strength, super durability and lost maintenance cost, concrete pavement is widely used, Meanwhile the phenomena of cracking damage caused by low stress extensively exist. Therefore the causes and mechanism of concrete pavement damage are jointly concerned by the researcher home and abroad.Nowadays pavement structure under static vehicle load is studied in all the pavement structure design. However considering the roughness of pavement, there is major difference between the research model and practical conditions of pavement in service. The paper discusses current situation which researchers are commit themselves to in this field, then presents the objects and main contents.Under coupling-among concrete slabs and vehicle-resulted from roughness of pavement, the response can decompose two parts: (1) deflection and stain arose by dynamic load applying on level pavement at certain velocity. (2) deflection and stain arose by slabs coupling due to roughness of pavement. So the paper systemically summarizes and discusses roughness of pavement resulted from the coupling mentioned above, subsequently with appropriate parameters it calculates deflection and stain in the bottom of slab/on the basis of current design theory. After studying one fourth vehicle model, the paper educes theoretically analytic formula of deflection and strain in the bottom of slab on the condition of dynamic load, then with appropriate parameters of pavement and vehicle system calculates dynamic stain in the bottom of slab which was compared and analyzed with the results educed at static load. As a result it concludes that for the reason of coupling among slabs and vehicle, strain in the bottom of slab is added 50～60% compared with the strain at static load.Repeated dynamic load applied on concrete pavement will induce fatigue failure. The paper presents the concept of concrete pavement cracking process analysis, which define cracking process as initial stage, middle stage and later stage. Subsequently the paper analyzes the relationship of the three stages, points out the basic reason of concrete pavement cracking formation at each stage, studies that dynamic load strengths slabs failure combined with coupling resulting in strain increase in the bottom of slabs. At last, this paper discusses the coupling of vehicle and slabs at the aspects of test on site and finite element simulation, analyses influence of concrete pavement performance arose by pavement roughness and velocity together with property of vehicle itself. After comparing and analyzing the results, the paper demonstrates the results analyzed in theory, presents the qualitative and quantitative relationship between fatigue failure and dynamic strain in the bottom of slab, provided new ways for later theoretical research of pavement design.The paper complies with the project of Chongqing Education Committee "Research on Cement Concrete Pavement Cracks by Vehicle-Road Interaction".