Durability And Traffic Safety Research On Asphalt Pavement In Large Longitudinal Slop Section In The Western Rainy Regions

In the western high-rainfall region of China with wide distribution of mountains and hills,terrain landform diversification and complex geological conditions.So the route designprocess is inevitable to a longitudial slope. Due to the high-rainfall and the longitudial slopespecial conditions in some western region, vehicles traveled with continuously accelerationand deceleration and brake frequently in the longitudial sections, thus it impose a greater levelof horizontal force to the longitudial sections, as well as bad interlayer boning, overloading,slow speed, high-rainfall and many other factors result the rutting, broaching and waterdamage of the longitudial slope more serious than the oridinary asphalt pavement. So it isgreat significance to study asphalt pavement of longitudial sections.This research mainly includes the following aspects:(1) This paper use the finite element software ANSYS and select a common asphaltpavement structure, through the establishment of a theory based on three-dimensionalviscoelastic finite element model, the paper expounds the two main damage forms oflongitudial slope asphalt pavement which are rutting and broaching, and analyses reasons ofdamage. Then longitudial slope pavement stress state under the action of layer interface,overload, longitudial slope, low speed and horizontal loads are further studied,and analysisthe change characteristics of depth of rutting and maximum shear stress under the action ofdifferent conditions, drawing the quantitative relationship among the various factors withrutting depth and maximum shear stress.(2) This paper establishs mechanical calculation models of hydrodynamic pressurebased on momentum theorem and the longitudial slope different stress conditions under thefour conditions that the depth of water film is smaller (<3mm) in the uphill and downhill, thedepth of water film is lager (≥3mm) in the uphill and downhill. According to the models, therelationship among hydrodynamic pressure and depth of water film, speed of vehicle, vehicleweight, longitudial slope are analyzed.(3) The water damage is more serious disease than any others in the early damage oflongitudial slope asphalt pavement. The infiltrated water from pavement surface, as well asthe coupled interaction between pavement structure and moving traffic loads is one of the keycauses which give the contribution to the water-induced damage. Therefore, based on Biotdynamic consolidation theory and characteristic of the longitudial slope,the hydro-mechanicalcoupled mode of two-dimensional three-layer system of saturated asphalt pavement whichinclude surface course, base course and subgrade was established and hydro-mechanicalcoupled governing equations of asphalt pavement subjected to moving traffic load are obtained.Under the condition of the surface course completely drainage, the papercomprehensive system analyse the influence of vehicle load, driving speed, pavementpermeability coefficient and longitudial slope on distribution of normal stress, pore-waterpressure, shear stress and surface course displacement, offerring the theoretical foundationand reference to the design of longitudial slope asphalt pavement structure.