Pavement Design in Takalimakan Desert

Abstract

The design method for pavements in the Takalimakan desert was proposed through the investigation of test roads and theoretical analysis. The function of geotextile in pavement structures is analyzed by the shear lag model, with a result that the shear bearing capacity of geotextile is proportional to its tensile modulus and the second derivative of its tensile deformation. Combining the layer-peeling method, a bearing plate method, and modulus back—calculation, the modulus of resilience of each layer in the pavement structure is determined. By means of multilayer elastic theory, the influence of contact conditions in the pavement on the tensile stresses and displacement is quantitatively analyzed. Stresses for unbonded wearing course and gravel-base course increase by more than four times. Change of contact conditions has little effect on the surface deflection. Therefore, the variation of surface deflection cannot reflect the shear instability between subbase and subgrade. Direct shear testing must be utilized to guarantee the shear stability in the pavement structure.