地震動の影響を受けた地域における降雨と斜面崩壊発生との関係について

Relationship between slope failure occurrence and precipitation in the areas affected by a strong motion of earthquake

Nishimura Masaru

Kaibori Masahiro

広島大学総合科学部紀要. IV, 理系編

Memoirs of the Faculty of Integrated Arts and Sciences, Hiroshima University. IV, Science reports

The number of collapses of slope induced by the Geiyo-earthquake occurred in March, 2001 wasoverwhelmingly small to compare with the number by other same degree earthquakes before. However, collapsesof slope are prone to occur relatively in a smaller amount of precipitation after the earthquake. The effectof seismic motion in the Geiyo-earthquake in 2001 was firstly evaluated by the maximum seismic acceleration,duration time of strong seismic motion and the direction of both strong motion and collapses of slope. And then,the amount of precipitation that was related to collapses of slope before and after the Geiyo-earthquake byexamining hourly rainfall and working rainfall (half-value period 72 hours) was considered. As a result, it wasfound that 60 to 80 percentage of precipitation, in which collapses of slope had been prone to occur before theearthquake, would be related to the phenomena such as slope failure and/or stone wall destruction, and landslidesmight occur to all direction regardless of the direction of strong motion over 250 gal in seismic acceleration.

Geiyo-earthquake

seismic motion

precipitation

collapse of slope

Earth sciences. Geology [ 450 ]

jpn

広島大学総合科学部

[ISSN] 1340-8364

[NCID] AN10435936