http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Development of a predictive model for pavement roughness on expansive clay
Expansive clays are the major cause of differential movements in shallow foundations. In highway pavements they are responsible for cyclic distortion of the riding surface resulting in a loss of road handling ability and service life of the pavement structure. Such distortion of the pavement surface is quantified in terms of its roughness. This work is primarily concerned with the prediction of such roughness based on climatic and soil conditions so that rational decisions may be made regarding the method that may be used in the control of such roughness. Of particular interest is the use of moisture barriers. This work is accomplished in three parts. In the first part, programs that quantify roughness in terms of three different parameters are developed and used to analyze the development of roughness at ten sites at which moisture barriers are installed in expansive clays. Roughness is interpreted through the analysis of relative elevation surface profiles recorded over a period of time of up to ten years. In the second phase, a parameter, which may be directly correlated to the development of roughness and which may be predicted through the analysis of climate and soil conditions, is developed. In the third and final phase, the rate of roughness development based on the three measures of roughness are related through regression to the soil and climatic parameter, the maximum expected vertical movement aH. The disciplines encountered are the analysis of roughness in traveled surfaces, the interpretation of climate, the modelling of unsaturated moisture movement and the modelling of soil deformation.