1g model test of piled-raft foundation subjected to vibration load and its simulation considering small confining stress

Abstract

The numerical simulations of 1 g model tests are presented to evaluate the feasibility of the proposed elasto-plastic constitutive model, which can precisely describe the less compressibility of clean sand under small confining stress. The dynamic responses of piled-raft foundations subjected to cyclic train loads were investigated by comparing the results of model tests and simulations. Different frequencies of dynamic loading and different grounds including dry loose sand, dry/saturated medium dense sand, were taken into consideration. It is confirmed that for all types of grounds and input vibration, the numerical results showed a good match with model tests data, especially the settlement and acceleration of piled-raft foundation. Both numerical simulations and experiments showed that the higher the frequency of the dynamic load is, the greater the peak acceleration will be. The proposed constitutive model has greatly improved the accuracy of the numerical simulations on the small-scale 1 g model tests because this model can accurately describe the mechanical characteristics of sand from very small confining stress to normal confining stress, especially the less compressibility and more dilative behavior of sand under small confining stress. • The proposed constitutive model can precisely describe the less compressibility of sand under small confining stress (CS). • The model tests were well reproduced by the numerical analysis with proposed constitutive model in the different grounds. • The proposed model has greatly improved the accuracy of the numerical simulation on the small-scale 1 g model test. • Excess pore water pressure was small both in the tests and simulations, because of more dilative behavior of sand at small CS.