Analysis of Shear Failure of Asphalt Pavement under Horizontal Force

Abstract

The finite element method is used to analyze the shear stress distribution of the pavement structure under vertical load and both vertical and horizontal load. The results show that the distribution coefficient of transverse force affects the distribution of shear stress with depth; The maximum shear stress increases with the increase of the lateral force coefficient, and the two have a linear relationship. When the horizontal force is considered, the shear stress of the asphalt surface layer increases and the peak value moves upward, which may cause rutting, displacement and swelling of the asphalt pavement. It is necessary to incorporate the horizontal force into the structural design index system. Introduction With the increasing of highway traffic volume and the development of heavy transportation, especially the operation of channelized traffic in high-grade highways, the rutting of asphalt pavement has become the main disease type [1] , and the main type of rutting is the fluidity rutting caused by the shear deformation of asphalt mixture [2,3] . In the summer high temperature season, the shear strength of the asphalt mixture gradually decreases with the increase of temperature. When the shear strength decreases to less than the shear stress, the asphalt mixture will produce shear deformation. Under the repeated action of the load, the wheel track will sag and both sides will rise, forming a W-shaped rut with a cross section. At the same time, displacement and swelling and washboard is also caused by the insufficient shear strength under the action of horizontal load at high temperature. Therefore, it is of great significance to optimize the design of pavement structure and reduce the occurrence of ruts to analyze the mechanics of multibrake sections such as steep road sections and toll stations considering the horizontal force and to explore the distribution law of shear stress. The Selection of Pavement Structure Parameters and the Establishment of Finite Element Model Pavement Structure Parameters Select the commonly used semi-rigid base asphalt pavement structure in China, and the material thickness and parameters are shown in Table 1. Table 1. Calculation parameters of pavement structure. Horizon Material Thicknesscm Modulus of compressive resilienceMPa Poiss0n ratio Above layer Fine grain asphalt concrete 4 1200 0.30 Middle surface layer Medium grain asphalt concrete 6 1000 0.30 Lower layer Coarse grained asphalt concrete 8 800 0.30 Base course Cement stabilized macadam 3