Shaking table tests on floatation of buried pipes in backfilled sand layer reinforced with geotextiles

Several series of shaking table tests were performed to investigate the effectiveness of geotextiles in reducing the floatation of buried pipes during earthquakes. The tests were conducted on model ground in which a trench with a width of 30 cm was excavated and then backfilled with loose sand. The model soil around the backfilled sand was composed of a dense sand layer which would not liquefy during shaking. In the tests, three kinds of geotextiles were installed right above the buried pipe, consecutively. Consequently, it was observed that the floatation of a buried pipe diminished as the mesh size of the geotextile decreased and as the bending stiffness of the geotextile increased.