Experimental Investigation of Lime as Subgrade Stabilizer for Ravi-Chenab Corridor Strata

Abstract

This study focuses on review of modern techniques/ technologies for improving trafficability of combat roads/ tracks with special emphasis on Ravi Chenab corridor and Pukhlian Salient in Central Comd AOR. The research work is primarily a lab-cum-field study for soil improvement using pozzolanic additives especially lime. In-situ soil conditions are evaluated through detailed investigation and identifying zones with similar soil profiles. Suitable percentages of soil stabilizer will be determined through array of tests to ascertain optimum blends for different types of soils present in the study area. Wide range of soil modification techniques; including but not limited to geo-synthetics, geo-grides and pozzolanic additives (lime, fly ash, baggas ash etc) are reported in literature for soil improvement/ stabilization with varying degree of success. However, various research studies have found lime outperforms all other modifiers for clayey soils, thus making it a preferred choice for our study to treat A-7-6, Clay, being the most problematic soil found in the study area. Soil treated with lime exhibits a significant decrease in Atterberg’s limit (plasticity index reduced by 79.96 %) of soil by lime modification. Classification of soil changed from AASHTO A-6 soil to A-4 soil and its behavior from clayey to silty soil, thus improving its trafficability class. Significant strength improvement (un-confined compressive strength increase by 37.05 %) of soil in soaked and unsoaked condition with the 4 % lime. In the light of the results obtained, it is concluded that 4 % lime can be used efficiently for improvement of weak subgrade (clayey) soils of the area of study.