Perpustakaan Digital ITB

On December 12, 1992 at 1.29 p.m local Central Indonesia Time, a tectonic earthquake of a magnitude 6.8 Richter scale, occured in Flores Island Nusa Tenggara Timur Province, Indonesia. The earthquake event caused a liquefaction which concentrated in Maumere City. The field observation of liquefaction-induced are sand boils, large deformation of the ground surface, and land subsidence. The focus of study is liquefaction phenomenon in Maumere City. The characteristics ground motion probable occured, was estimated from empirical correlation on rock formation, then to be basis for analysis. This characteristics to be input of a computer program SHAKE for finding out ground motion characteristics on ground surface. One of the important characteristics is maximum acceleration, which used in simplified procedure of Seed et al.The N-SPT data obtained after earthquake event was used in this study with related to cyclic stress ratio. The correlation of N-SPT and cyclic stress ratio was plotted in a chart, thereby obtained a bound line separated between liquefaction did or not, based on field performance. The properties of grain size distribution was plotted for gave a bound between liquefaction did or not. Mapping with concerned to geology criterion was did, that indicated a susceptibility of liquefaction area are marine deposit and little river deposit. The result of this criterion is depth of ground water less than 3.0 meters for liquefaction zone. Analytical study with a computer program LIOU was executed to received a process of liquefaction occurence in Maumere comparatively to non liquefaction.