孔中固定式受震器によるS波の速度分布の測定

Abstract

The shear wave was observed by the clamped borehole geophone specially designed by oneof the authors, C. Kitsunezaki, of which details have been reported in the same author's earlierpaper.Striking against wooden plate fixed on the ground surface near the top of the borehole bya hammer served as the wave source. By the above arrangements, the shear wave propagatingsn vertical direction was observed at every position where the geophone was clamped.The wave feature on the records obtained by this method is very beautiful and its character-isties is rational in the following two factors; particle motion, and relation of the response betweenthe usual velocity pick-up and the pressure pick-up.The shear wave velocity shows distinct character in the relation to the kind of the materials, namely, sand and clay. The velocity is higher in sand than in clay, and the velocity in the re-spective media increases with the increase in depth.