APPLICATION OF MICROTREMOR MEASUREMENT FOR ESTIMATE OF OVERALL STIFFNESS OF LEVEES

Abstract

This study explores the feasibility of estimating overall shear wave velocity for levees to detect weak sections by using microtremor measurement. Microtremor measurement is carried out on the crest and near the toe of the levee embankment simultaneously by placing servo-type velocity sensors perpendicular to the levee axis. Then, transfer functions are calculated using the horizontal motions. Finally, overall shear wave velocity structure is identified so that the peak frequency of the transfer function and the fundamental frequency of finite element model of the levee that has the same cross section coincide. The identified shear wave velocities are mostly consistent with shear wave velocities estimated based on SPT blow counts. Hence, this method is feasible to detect weak sections along levees.