Application of acceleration measurement method for estimating the stiffness of unbound aggregates in roadbed

摘要

In this paper, we describe the transit elastic wave system for measuring the wave velocities of unbound granular aggregates in base and subgrade. The technique is based on the measurements of surface responses due to an impact at the surface using a portable FWD. The portable system consists of a portable PC, a sampling A/D card (the sampling interval is 0.05 msec), an acceleration system, a portable FWD and Matlab-based software. Measurements of the elastic wave velocities on the unbound granular aggregates base as well as the subgrade have demonstrated its potential in the nondestructive evaluation of unbound granular aggregates structure. The developed portable transient elastic wave system can be utilized to measure the in-situ elastic wave velocities of base and subgrade in pavements and further to evaluate the quality of the base and subgrade structure.