Lateral displacement of soft ground under vacuum pressure and surcharge load

Surcharge load (e. g. embankment fill) will induce settlement and outward lateral displacement, while vacuum pressure will induce settlement and inward lateral displacement of a ground. Ideally, combination of surcharge load and vacuum pressure can reduce or minimize the lateral displacement. Laboratory large scale model (length: 1.50 m, width: ~0.62 m, height: 0.85 m) tests and finite element analyses (FEA) were conducted to investigate the main influencing factors on lateral displacement of a soft clayey ground under the combination of vacuum pressure and surcharge load. For the conditions investigated, the results indicate that the outward lateral displacement increases with the increase of the ratio of surcharge load to vacuum pressure (RL) and the loading rate of the surcharge load (LR). Also, it is shown that for a given RL and LR condition, lateral displacement reduces with the increase of the initial undrained shear strength (Su) of the ground. To predict the lateral displacement of a ground under the combination of surcharge load and vacuum pressure, the loading conditions in terms of RL and LR, and Su value of the ground have to be considered. © 2011 Higher Education Press and Springer-Verlag Berlin Heidelberg.