Senior research engineer, Danish Road Institute, National Road Laboratory, Roskilde,
Pages: 16 Published: Jan 1994
This paper reports results from a research program assessing pavement response from heavy vehicles. The Technical University of Denmark and The Danish Road Institute cooperated in the research program. To estimate the validity of theoretical values of stress and strain in pavements, stress and strain distributions were measured under two types of loads. One was the rolling truck tires of the Road Testing Machine, and the other was falling weight deflectometer (FWD) loadings. Distributions of stress and strain are explored and mapped in three-dimensional graphs. Some steps are taken in an attempt to test measured response distributions against calculated distributions. The measured responses are: (1) vertical contact stress in the tire/pavement interface, (2) longitudinal and transversal strain at the bottom of the asphalt concrete layer, (3) vertical soil stress, and (4) vertical soil strain.
As temperatures and layer thicknesses in the Road Testing Machine are well known, only Poisson's ratio is estimated for the calculations. The layer's E-values were backcalculated from the FWD load and measured surface deflections. Using the elastic layer theory with backcalculated E-values and the chosen values of Poisson's ratio, values of stress and strain are calculated at the positions of the instruments. FWD load response values are considered the means for in situ calibration of stress cells.
pavement, test, instrumentation, measurements, stress, stress analysis, strain, Denmark, research project
Paper ID: STP13250S