Determination of Resilient Modulus of Soil Subgrade from Index Properties Using Geoguage

Abstract

Currently the design of Flexible Pavement is generally conducted based on static properties such as California Bearing Ratio and soil support value. These properties do not represent the actual response of the pavement layers under traffic loading. Recognizing this efficiency, the current and the 2002 mechanistic empirical guide for design of pavement structures recommended the use of resilient modulus for characterizing the base and subgrade in terms of resilient modulus for the design of flexible pavement. The first objective of this study was to estimate the resilient modulus for different soil subgrades from in-situ device Geogauge in corporating the soil index properties. The second objective is Correlating Geogauge with Dynamic cone penetrometer in-situ and laboratory; models are developed to predict stiffness and young's modulus from DCP penetration test. Different types of soils were taken and compacted at different dry density in the laboratory and models were developed in terms of number of blows and the resilient modulus values and can be effectively used to assess the resilient modulus. Resilient modulus values are generally obtained by conducting repeated load triaxial tests on reconstituted or undisturbed cylindrical specimens. Because the test is complex and time consuming, in-situ tests would be desirable if reliable correlation equation could be established alternatively.