Undrained loading and collapse of unsaturated soils during centrifuge testing. An experimental and numerical study

摘要

The paper presents the results of a centrifuge model of a shallow foundation udrelying of a layer of unsaturated soil and submitted to axial load for different water level. udThe objective of the work was to represent a foundation of 1.5 m in diameter on a 15 m soil udlayer. The model of foundation was a circular disk of 30 mm in diameter and the layer was a udcylindrical container of 300 mm in diameter and height. In order to maintain similitude udbetween prototype and model the tests were carried out at 50g. The tests were carried out at udthe LCPC facilities in Nantes (France). The tested material is an eolian silt from Jossigny, udEast of Paris. In order to decide the initial conditions of the model in terms of water content udand void ratio it was performed a preliminary laboratory investigations. As the intention of udthe study was to examine the behaviour of a collapsible soil therefore it was decided to udprepare the model with a low dry density (14.5 kN/m3ud). The evolution of pore water pressure udduring the tests are compared with the numerical simulation of the prototype with code udbrigh