A METHOD FOR DYNAMIC CHARACTERISTICS ESTIMATION OF SUBSURFACE USING MICROTREMOR ON THE GROUND SURFACE

As methods for dynamic characteristics estimation of surface layers, investigation with boring and a method which employs microtremor are well known so far. Boring investigation, one of the most accurate methods is costly and time consuming and is not available all the time. The method that employs microtremor is handy but has not produced satisfactory result to this day. This paper describes a new processing method that employs microtremor observation yet producing accurate estimation of characteristics of the ground motion. The method uses vertical component and horizontal components. As a result, the spectrum ratio of the horizontal components and vertical component of microtremor bears resemblance to transfer function for horizontal motion of surface layers.