Critical Pavement Response Analysis of Pond Ash Stabilized Subgrade Using Non-linear Approach

摘要

Design of flexible pavements incorporates mechanistic empirical approach pertaining to limiting stresses and strains at critical locations. In order to properly characterize the resilient behaviour of pavement foundations, non-linear stress dependent modulus models need to be incorporated in the analysis. The study conducted here focuses on employing non linear behaviour of subgrade in KENLAYER software for mechanistic pavement analysis. Road network being a major and preferential communication system draws attention towards an urgent need for sustainable construction of new roads. Pond ash produced by coal based thermal power plants takes huge disposal area and creates environmental problems like leaching and dusting. The present study investigates the effect of non-linearity on clayey subgrade stabilized with pond ash. Geotechnical studies were conducted by blending pond ash with 10%, 20%, 30% and 40% by mass of soil. The improvement in the characteristics of stabilized soils was assessed by evaluating the changes in the physical and strength parameters namely, the California Bearing Ratio (CBR) and compaction parameters. Significant improvement in geotechnical properties was observed leading to remarkable reduction in pavement thicknesses. It was observed that the assumption of linearity in the material behaviour gives a conservative design approach in terms of critical failure due to passes and critical strains. The critical pavement response reported with pond ash stabilization shows considerable improvement in increasing the rutting and fatigue life of pavement. At low CBR percentages, the critical strains were found to be high emphasizing the fact that benefit of pond ash stabilization will be prominent.