000019326 001__ 19326
000019326 005__ 20170118182311.0
000019326 04107 $$aeng
000019326 046__ $$k2017-01-09
000019326 100__ $$aKwon, Oh-Sung
000019326 24500 $$aSeismic Soil-Structure-Interaction Analysis Method for Shallow Foundations

000019326 24630 $$n16.$$pProceedings of the 16th World Conference on Earthquake Engineering
000019326 260__ $$b
000019326 506__ $$arestricted
000019326 520__ $$2eng$$aThis paper introduces a new approach for seismic Soil-Structure Interaction (SSI) analysis of shallow foundations using computationally efficient yet practically accurate models. The study is inspired by the increasing interests amongst engineers and researchers in the nonlinear cyclic or rocking behavior of shallow foundation. Furthermore as the industry moves toward the performance based seismic design, the accurate modelling of the inelastic cyclic or rocking behaviour of shallow foundation has attracted considerable attention of researchers. There are two main characteristics of a shallow foundation that need to be considered in a numerical model: inelastic cyclic behaviour of near field soil and frequency-dependent characteristic of soil. One of the rigorous and computationally expensive approaches which can capture both characteristics is to use a sophisticated constitutive model of soil materials, and developing a fine mesh of soil-foundation system using the finite element method. However, due to the extremely large modelling efforts and computational time, the FEM approach is not a feasible option in a routine engineering practice. To overcome the limitation, researchers have proposed macro-elements. In the macro elements, the inelastic cyclic behavior of soil-foundation interaction is captured at the lumped node where geometric nonlinearity such as uplift and sliding of the foundation as well as material nonlinearity are modelled simultaneously. The macro element’s inelastic behaviour is defined by a plasticity law where its stiffness is updated at each computational step using the generalized force-displacement relationship with the bounding surface hypo-plastic model. Macro-element is able to capture the inelastic behavior of the soil foundation system at the vicinity of the foundation. As the element replaces soil and foundation with hypo-plastic spring model, the soil mass and damping properties are missing in this element, which results in inability to capture wave propagation from the foundation to the structure. Soil exhibits frequency-dependent characteristic of stiffness and energy dissipation. Inclusion of the dynamic stiffness is pivotal in order to extend the application of this element to the domain of dynamic loading condition. In the current practices, the soil-foundation system is often modelled with elastic springs and dampers for simplicity which are inherently frequency-independent. In reality, soil exhibits frequency dependent characteristic at different frequencies of excitation. In this paper, it is proposed to integrate a macro element which can capture the inelastic cyclic behaviour of soilfoundation system with a recursive parameter model which can model the frequency-dependent dynamic stiffness in time domain. By the integration of these two models, it can approximately capture the inelastic SSI effect of the soil foundation system and the frequency dependency of soil simultaneously. First part of the paper presents the introduction of the macro-element and the second part of the paper introduces the recursive parameter model. Then, the paper illustrates the combination of the two models using schematic diagrams and equations. The verification of the proposed method is provided with FEM model.

000019326 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000019326 653__ $$aShallow foundation, Soil-structure interaction (SSI), Macro-element, and Frequency-dependency of soil.

000019326 7112_ $$a16th World Conference on Earthquake Engineering$$cSantiago (CL)$$d2017-01-09 / 2017-01-13$$gWCEE16
000019326 720__ $$aKwon, Oh-Sung$$iGhaemmaghami, Amirreza$$iChai, Seok Hyeon
000019326 8560_ $$ffischerc@itam.cas.cz
000019326 8564_ $$s479701$$uhttps://invenio.itam.cas.cz/record/19326/files/3391.pdf$$yOriginal version of the author's contribution as presented on USB, paper 3391.
000019326 962__ $$r16048
000019326 980__ $$aPAPER