APPLICABILITY OF NEWLY-DEVELOPED INSTRUMENT FOR MICROTREMOR MEASUREMENTS TO ESTIMATE THE LOOSENED ZONE IN SHALLOW GROUND

摘要

After large earthquakes, slope failures induced by a small rainfall were often reported. However, such a failure could not be caused in usual situation. The reason why such failures are caused is that the instabilities of ground (looseness of ground) are caused due to a seismic motion. Such a loosened ground causes troubles in many construction cases. It is possible to estimate the looseness of the ground qualitatively, but it is hard to estimate it quantitatively. It has reported that microtremor measurement is useful for estimating looseness of ground by Seiji Kano etc. However, the conventional microtremor is not suitable to get information of shallow ground. To know the properties of shallow ground, a newly method of microtremor measurement with pile-shaped instrument has been proposed in this paper.