Displacement-Based Design of Shallow Foundations With Macroelement

The role of non-linear dynamic soil-foundation interaction on the seismic response of structures

“…The macro-element was further extended by Cremer et al (2001Cremer et al ( , 2002in order to consider all the material and geometrical non-linearities at the soil-footing interface, the coupling between them and their coupling with the response of the superstructure. Such macro-element was developed for strip footings, while the latest generations of macroelements for shallow foundations (Chatzigogos et al 2009(Chatzigogos et al , 2011Figini et al 2012)are 2006) and by Grange et al (2008). The various examples of application have proven that this modeling approach is a very cost-effective solution in terms of the balance between physical behavior, simulation accuracy and computational cost (see, e.g., Muir Wood 2007, for a review).…”

“…-The non-linear elastic components qel−nlin representing either the uplift or the gap formation mechanism, can be generically linked to the force increment Q by a stiffness matrix k el−nlin which, at variance with the previous case, is now function of the level of displacements in the system. Such dependence, defined by appropriate analytical expressions, can be expressed either directly on the reversible components of total displacements, as it has been done in the formulation presented by Chatzigogos et al (2009Chatzigogos et al ( , 2011 (general uplift model for shallow foundations of arbitrary shape) or indirectly, by means of auxiliary geometric parameters that evolve according to the loading history. Examples of such auxiliary quantities, are the percentage of uplifted width in the strip footing macroelement model presented by Cremer et al (2002) and the current gap depth parameter introduced in the pile macro-element presented by Correia et al (2012).…”

On the performance of lumped parameter models with gyro‐mass elements for the impedance function of a pile‐group supporting a single‐degree‐of‐freedom system

“…For example, Chatzigogos et al . proposed a new macroelement model for expressing the nonlinearity of a shallow foundation. In their papers, they referred to GLPMs as sophisticated models that may remedy the issue of frequency dependency of IFs in the macroelement model.…”

“…In recent years, GLPMs have gradually been recognized as a promising tool to express frequency-dependent IFs. For example, Chatzigogos et al [15,16] proposed a new macroelement model for expressing the nonlinearity of a shallow foundation. In their papers, they referred to GLPMs as sophisticated models that may remedy the issue of frequency dependency of IFs in the macroelement model.Although GLPMs show great potential for solving various dynamic problems of pile groups interacting with structures, some problems remain.…”

Foundations

“…The kinematic hardening model for cyclic loads and the gapping-contact interaction model on the interface of the foundation and the ground were developed and implemented (Chatzigogos et al, 2009 Using a series of centrifuge tests, a bearing capacity problem of two-layered soils was investigated by Okamura et al (1997), where a sand layer was overlaid over a soft clay layer. Murakami et al (1996) carried out numerical simulations with the use of Cosserat media to take the bending resistance of the surface crust into account.…”