The Structural Response and Behaviour Prediction of Subgrade Soils Using Falling Weight Deflectometer in Pavement Construction

摘要

In concrete and flexible pavement construction, the conditions of a subgrade soil are determined by the in-situ Plate Bearing and California Bearing Ratio test respectively. From the in-situ tests, the modulus of subgrade reaction and California Bearing Ratio of subgrade soils, which are the essential design parameters for the pavement designs can be established. The elastic modulus of the subgrade soils which is an important material properties was rarely detemined during the pavement construction. The subgrades' modulus of elasticity is needed in the determination of the pavement response such as stresses, strains and deflection in each pavement layer for mechanistic pavement design. An attempt has been made in this research study to backcalculate the in-situ elastic modulus during subgrade construction using the deflection data from falling weight deflectometer. A comparison was made between the backcalculated elastic modulus of the subgrade and the field elastic modulus as determined by the Dynamic Cone Penetrometer testing device.