The Correlation between Static and Dynamic Moduli in Embankment of High Speed Railway

The static modulus of elasticity from the load-settlement line of a second load cycle in a plate load test (PLT), Ev2, is a key parameter to control embankment bearing capacity, settlement and track quality in general. Because of the greater sensitivity in bearing capacity and settlement of high speed understructure, more strict limitations in this issue should be concerned in high speed rail codes so as each individual layer of fill should satisfy a special amount of Ev2. The PLT, as a test to determine Ev2, is expensive and time consuming. But, tests like Light Weight Deflectometer (LWD) that determines the dynamic modulus of elasticity could be economically more efficient. In this study, field data from several PLT and LWD tests, which have been performed over different layers of embankment in the Qom-Isfahan high speed railway, were analyzed. Then, linear and non-linear regression methods were used to extract the best-fit equations among the results. Similary, the relationship between these field data and laboratory tests of California bearing ratio was extracted. Furthermore, back-calculation was used to determine the static and dynamic elastic moduli of each layer individually.