Seismic Behaviour of Geosynthetic-Reinforced Slopes with Overload by Shaking Table Tests: Fid-Bau Portal

Seismic Behaviour of Geosynthetic-Reinforced Slopes with Overload by Shaking Table Tests

Lo Grasso, A. S. / Maugeri, M. / Recalcati, P.

Recent earthquakes events in Japan, United States, Turkey, Iran, Italy have increase the interest to the analysis of soil structures subjected to seismic loads. The common procedure used to design slopes is based on limit equilibrium methods. The method is used to analyse the stability of slopes with and without reinforcements. The performance of reinforced soil slopes were investigated in this paper by a number of shaking table tests carried out in the University of Catania shaking table facilities. The required length of reinforcements was calculated using the relationship of Jewell as modified and proposed by Cascone, Maugeri, Motta for the seismic design. All reinforced slopes models were built with the inclination respect the horizontal of 70° and height of 0.35m. The soil used in the tests is a typical dry silica sand of the East Coast of Sicily. The reinforcement, chosen to obtain a good scale factors with the model, is a bi-directional polypropylene geogrid. Each tests is subjected to a uniform surcharge obtained by small block elements with the purpose to apply a load value of 1 kPa. The models were subjected to a sinusoidal progressively increasing acceleration and to the E-W component of Catania earthquake of 1990. Moreover the shaking table tests were performed to investigate the effects of the reinforcements vertical spacing. Model deformations were found to be depending on the reinforcements spacing and on the level acceleration of the input motion. Two-wedge failure mechanism is a dominant one as showed by the failure surfaces observed.