Response of geosynthetics under earthquake excitations: Fid-Bau Portal

Response of geosynthetics under earthquake excitations

Yegian, M. / Yee, Z. / Harb, J.

The seismic response of a geosynthetic interface system is investigated using shaking-tabel tests. Under harmonic type excitation, results show a limited shear stress, and therefore, acceleration transferred through the interface. Beyond this 'yield' acceleration, relative displacement or slip deformation occurs along the geosynthetic interface. Similarly, under earthquake-type excitation, a reduced acceleration is trandmitted through the geosynthetic interface. However, the yield acceleration is not constant and varies from one pulse to another. In the vicinity of the predominant frequency of the ground motion, the spectral acceleration of the transmitted motion is deamplified. This deamplification is a function of the peak ground acceleration of the base motion and the frequency content. Beyond a peak acceleration of 0.2 g, the geosynthetic interface (HDPE/Polyfelt) acts as a base isolation and absorbs the wave energy through relative displacements or slip. Relative displacement is also investigated on a horizontal geosynthetic interface using three different earthquake-type motions. The maximum slip deformation during an earthquake can be larger than the permanent displacement along a geosynthetic interface, and should be considered to ensure the integrity of the landfill liner system.