a macro-element for modeling the non-linear interaction of soil-shallow foundation under seismic loading

a macro-element for modeling the non-linear interaction of soil-shallow foundation under seismic loading

this paper presents a macro-element for simulating the seismic behavior of the soil- shallow foundation interaction. the overall behavior in the soil and at the interface is replaced by a macro-element located at the base of the superstructure. the element reproduces the irreversible elastoplastic soil behavior (material non-linearity) and the foundation uplift (geometric non-linearity) at the soil- foundation interface. this new macro-element model with three degrees-of-freedom describes the force-displacement behavior of the footing center. the single element is restrained by the system of equivalent springs and dashpots.

the footing is considered as a rigid body. it is solved by a suitable newmark time integration scheme and implemented in matlab to simulate the nonlinear behavior of soil-shallow foundation interaction under seismic loading. a reduce scaled soil-foundation system has been tested on a shaking table at the university of transport and communications, hanoi, vietnam. five series of earthquake motions were used with maximum acceleration increased from 0.5 𝑚/𝑠² to 2.5 𝑚/𝑠². the comparison of numerical results obtained from the simulation and experimentations shows the satisfactory agreement of the model. the proposed macro-element can be used to predict the seismic behavior of a wider variety of configurations.