Research On The Design Method Of Asphalt Pavement Structure In Soft Soil Area

The soft soil is a kind of special soil which has characteristics of high watercontent, large compressibility and low intensity. This type of soil is wildly distributed inChina’s eastern and southern coastal areas, such as Yangtze River Delta, Pearl RiverDelta and so on, and also exist in some inland areas that near rivers.The soft soil has anunique physical and mechanical properties, which decides the complexity of asphaltpavement structural design in these areas.Soft soil roadbed generally has some settlement after construction,which induceduneven road settlement and incidental tensile stress in pavement structure.When theadditional stress exceeds the structural material’s tolerance tensile stress, the pavementsearly damage will be produced. Therefore, it is necessary to study on the asphaltpavement structural design of soft soil subgrade.This article adopts methods of finite elements,analysises the settlement law ofsoft roadbed in different soft soil layer thickness and embankment heightconditions,then compares the results with field test datas,on the base of above,regressesthe settlement curves. And the displacement loads due to settlement are applied in theform of4kinds of pavement structure at the bottom, reaching value of additional tensilestress in each structure layer. In this paper,analysises the varity of deflection and bottomlayer tensile stress of pavements under loading.Then,the paper calculates the sum ofload stress and additional stress at Layer Controlled By Stress in every pavement.Next,analysises the adaptability of different structure types on uneven settlement and gets theasphalt pavement typical structures based on the load,different settlement and soil basetype.Finally,the paper supplements the design index of pavement structure, proposedtypical asphalt pavement structure and design methods in soft soil regions.