APPROXIMATE EVALUATION OF GROUND-MOTION INTENSITY FROM UPTHROWN BOULDERS
飛石現象に基づく地震動強さの簡略的評価

Yasuhiro HAYASHI, Mika KANEKO, Takahide WATANABE
2001 Journal of Structural and Construction Engineering (Transactions of AIJ)  
The estimation ofnear −field ground motion intensity is an importanI sゆ jecnn ea 皿 hq岨 ke engineering . However , 吐 he characteristics ofnear − fietd grQund motion are not well known because of the limited amounl ofrecorded dala from the epicentral regions , Some posI − ea 曲 quake investigatio 皿 reports have pointed ouUhat the up 山 row of bou艮ders in the epicentral region might be evidence ofextr ¢ mely strong ground motions . In this paper, the upthrow phenomenen is interpreted through
more » ... l simulations and sha } dng − table experiments , and a rr に thod ofestimating gr〔 》und − motion intensity from bould¢ rupthrow phenomenon is propQsed. The conciusions reached on the basis ofthe resui 【 s of our studies are as fbllows :( a )The uplhrow phenomenon is mainly the result of the large −velocity amplitude ofground molions at the soil surface . ( b)BouiderupIhrow is caused by periodic modon ra 【 hcr than impulsive motion ,( c ) An equation by which the maxlmum velocity of ground motion is estimated from the horizonta1 displacement of a bou【 der has been proposed based on numerica1 simulations assuming the ground motion to be a sine wave . The proposed formula shows good correspondence with the results of our shaking − table experirnents .
doi:10.3130/aijs.66.43_1 fatcat:n7n4rlmgcbbj7kt5egenstr5ty