Structural Stability And Optimum Design Of Permeable Interlocking Concrete Pavements

Permeable interlocking concrete pavement is one of the common pervious pavement types composed by surface,bedding layer,base and subbase.Its surface layer is mainly composed of concrete pavement bricks and joints between bricks.The pervious function of the pavement is realized by filling small size pervious materials in the joints.The whole pavement structure has the advantages of high bearing capacity,good durability and convenient maintenance.In this paper,the structural design method and the structural bearing characteristics of the permeable pavement are tested and theoretically studied.The main research contents are as follows:(1)The design method of the Permeable interlocking concrete pavement is carried out from two aspects of hydrologic and structural design.The optimization index and secondary index of pavement design are put forward,and the calculation method of each design index is determined.The paper also interacts the two contents of hydrologica design and structural design and establishes a relatively complete design method of pavement structure.(2)The influence of joint width,type of joint filling material and thickness of bedding layer on the lock degree of pavement brick and joint filling material under load is studied by orthogonal test method.The test confirms the existence of "arch effect",and analyzes the bearing characteristics and mechanism of "variable stiffness" of pavement under load.The results show that the strength of "arch effect" will show a trend from weak to strong to stable The trend of change in the final rout.(3)The influence of void ratio and gradation of crushed stone base on the vertical permanent deformation of pavement structure is tested by cycle loading test.The results show that with the increase of loading times,the vertical deformation of pavement increases gradually.The prediction model between the permanent deformation and the void ratio of base course is established,and the correlation coefficient reaches 0.98734,combined with the test data,The load deflection curve of the permeable interlocking concrete pavement is proposed,and the bearing mechanism of the whole pavement structure is analyzed.(4)Based on the ANSYS finite element calculation software,a three-dimensional finite element model of the permeable interlocking concrete pavement is established,and the variation trend of the vertical deformation of the pavement structure along the depth direction and the horizontal direction with the cyclic load is analyzed.The results show that the change of the vertical displacement keeps the same height with the load effect.Through the analysis and research of the bearing performance of the pavement,the optimization design of the pavement structure is carried out.