Behavior of Tensionless foundation with an Improved Winkler Model Subjected to Earthquake Loading

摘要

The nonlinear beam resting on a nonlinear backfill soil subjected to earthquake loading is analyzed with the development of fiber beam element. The Winkler approach models the soil as a single layer, and assumes that the foundation reaction at a particular point is proportional to the soil displacement. In this paper a new finite element formulation was developed to simulate the earthquake performance in which the soil can be viewed as a semi-infinite inelastic element that can resist bending, in addition to the well-known Winkler effect. The non linear response of structures resting on this improved foundation model is analyzed following a Pasternak approach with soil parameters based on a plane strain assumption. The tensionless character of the foundation results in the creation of lift-offs between the beam and foundation is also being considered. Parametric analyses of the structures were carried out and comparisons were made with the simple Winkler model. The presented solutions and applications show the superiority of the element in simulating the complex response of foundation structures.