Dynamic Performance Analysis Of Joint On Cement Concrete Pavement

In order to reduce the influence of the expansion stress and warping stress of cement concrete pavement slab,and to avoid pavement cracks,many joints need to be set up.Joint is not only an indispensable part of cement concrete pavement,but also the root of many diseases such as mud pumping,dislocation and broken slab.Therefore,the study of the stress distribution and failure mechanism of pavement joints has certain guiding significance to the optimization design of pavement and joint and the decrease of the disease occurrence of pavement.In this paper,aiming at the problem of pavement joints,the concrete pavement structure model with joint is established by means of finite element software.By a nalyzing the mechanical response of pavement joints under moving vehicle load,the time history curves of bending,vertical compressive stress,horizontal shear stress and the first principal stress of the joints are obtained.By comparing the results of a series of finite element model,the influence of the load,the speed,the roughness of pavement and the height of the platform staggered on the dynamic performance of the joint is obtained.The test method is used to study the load carrying capacity of the transmission lever.The results are as follows.In the first 50000 cycles of cyclic loading,the load transfer ability of the specimen is decreased obviously.The larger the diameter of the transmitting rod is,the stronger the load transfer ability is.But when the diameter is more than 30 mm,the diameter of the increase cannot effectively improve the capacity of load transfer.The load transfer coefficient increases with the increase of the length of the transmission force,but the growth trend gradually slow down.With the increase of concrete slab thickness,the coefficient of load transfer is slightly increased.