Critical Pavement Response Analysis Under Overloading for Design of Low Volume Rural Roads

Abstract

AbstractThis study is focused on analyzing the effects of overloaded vehicles on low volume roads and their comparison with standard axle load of 81.60 kN. The overloads assumed are 1.25 times, 1.50 times and 2.0 times the standard axle load. The main objective of this research is to check the trends in the values of tensile strain, vertical strain and vertical surface deflections in pavement with respect to subgrade modulus and high pressure intensities. Results indicate that the effect of overloading and varying pressure intensities is significant on compressive strain; however effect on tensile strain is comparatively insignificant. The compressive strains increase by almost 95% when overloading is increased by 2 times the standard axle load while a significant rise of almost 50% is also seen when overloading is increased by 1.25 times the standard axle load. When the overloading is 2 times the standard axle load, it has been observed that fatigue cycles decrease by almost 40% while varying the subgrade modulus. Also, for the same condition of 2 times overloading, the fatigue cycles decrease by almost 70% while varying the pressure intensities. Further analysis reveals that the cumulative cycles reduce by almost 95% for both the cases and hence, highlights the importance of overloading in design criteria. The allowable overload limit in India is 1.25 times the standard axle load and hence, design charts are created for overloading phenomena by using 1.25 times the standard axle load as the ultimate load to create realistic and long-lasting design of low volume roads.KeywordsOverloadingLow volume roadsFatigueRutting