Influence of bearing pressure on liquefaction-induced settlement of shallow foundations

Earthquake-induced soil liquefaction continues to pose problems for structures on shallow foundations. One particular problem is the excessive settlement that such structures undergo as a consequence of earthquake shaking. For design and insurance purposes it is therefore necessary to be able to estimate the magnitude of these settlements. Current procedures relate the potential settlement to foundation size and liquefiable depth. However, the influence of foundation bearing pressure is also a significant factor. In particular, experimental results have indicated that large bearing pressures may inhibit liquefaction underneath a shallow foundation, resulting in lower induced settlement. By collecting new data from 23 buildings that suffered settlement and tilting as a consequence of soil liquefaction during the 27 February 2010 Maule earthquake in Chile, the existing method of estimating liquefaction-induced settlement is reassessed and shown to require bearing pressure information. Based on both the new and previously available data, a maximum potential settlement based on both foundation area and bearing pressure is proposed.