Validation of liquefaction prediction models from geotechnical centrifuge tests results

Abstract

The damage resulting from earthquakes can result from the combination of seismic excitation and/or due to a build-up of excess pore pressure in the soil (liquefaction). These two effects are related, since the reduction in soil stiffness due to a decrease in effective stress changes the mechanical behaviour of the soil namely its seismic response. Therefore the expected level and type of damage is dependent on the rate of pore pressure build-up and time of liquefaction triggering in the soil, with respect to the release of seismic energy with time. However, most simplified liquefaction assessment methods are focused on liquefaction triggering and not on the time at which it occurs. Therefore, the improvement and development of these methods is essential so that they can provide reliable estimates of the effect of pore pressure increase and consequent liquefaction of sensitive layers. In that sense, centrifuge tests are an excellent opportunity to validate these methods. This paper presents two simplified liquefaction assessment methods, which are used to predict the pore pressure build up in a series of centrifuge tests.