Conversion between static and dynamic load bearing capacity moduli and introduction of dynamic target values

Abstract

Two types of Light Falling Weight Deflectometers (LFWD) are in use in Hungary: the German device (Zorn, HMP and Wemex) and the new B \rm & C small-plate device, which was developed by Andreas Ltd. Both devices are able to measure the dynamic load bearing capacity of subgrades, subsoils, embankment layers and backfills. Extensive application of these apparatus still has not been achieved since the dynamic modulus is not accepted in the quality assessment and quality control process of embankments and subgrade layers. Only marginal use of these devices can be noticed, mainly on areas of low importance (e.g. road shoulders) or trenches where performing a static plate load test could be complicated. For being able to use these dynamic devices on embankment layers, research for converting the measured dynamic modulus into static modulus has been initiated. First results of this research are presented in this paper. Using international and Hungarian measurement results, required target values for E_vd and E_d have been proposed for implementation.