000013310 001__ 13310
000013310 005__ 20161114160336.0
000013310 04107 $$aeng
000013310 046__ $$k2009-06-22
000013310 100__ $$aSaitoh, M.
000013310 24500 $$aNonlinear response of superstructures influenced by frequency-dependent oscillations in impedance functions of pile groups embedded in a layered soil

000013310 24630 $$n2.$$pComputational Methods in Structural Dynamics and Earhquake Engineering
000013310 260__ $$bNational Technical University of Athens, 2009
000013310 506__ $$arestricted
000013310 520__ $$2eng$$aThis paper presents the effects of frequency-dependent oscillations in the impedance functions of a pile group embedded in a layered soil medium upon the dynamic nonlinear responses of structural systems. Single-degree-of-freedom systems with various natural frequencies and yielding strengths are taken into consideration for superstructures. The impedance functions in the horizontal and rotational directions evaluated by using the Flexible Volume Method are simulated based on a so called “Gyromass Element Method (GEM)”. This author proposed a simple parameter model that can simulate various types of frequency-dependent impedance functions by using a mechanical element called a "gyromass", a frequency-independent element defined as a unit system that generates a reaction force due to the relative acceleration of the nodes between which the gyromass is placed. This method can calculate the time-history response of inelastic structures supported by soil-foundation systems showing frequency-dependent oscillations in their impedance functions. In this study, responses of the superstructures evaluated by the GEM and by an approximate method using static impedance functions are compared. The numerical results show the tendencies of the responses of structural systems to be influenced by oscillations in the impedance functions, such that the oscillations may affect superstructures that have particular natural frequencies and yield strengths, and may affect the responses of inelastic structures more strongly than elastic structures.

000013310 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000013310 653__ $$aSoil-structure interaction, Elastic foundations, Soil-pile interaction, Dynamic analysis, Pile group, Impedance, Nonlinearity. Abstract. This paper presents the effects of frequency-dependent oscillations in the impedance functions of a pile group embedded in a layered soil medium upon the dynamic nonlinear responses of structural systems. Single-degree-of-freedom systems with various natural frequencies and yielding strengths are taken into consideration for superstructures. The impedance functions in the horizontal and rotational directions evaluated by using the Flexible Volume Method are simulated based on a so called “Gyromass Element Method (GEM)”. This author proposed a simple parameter model that can simulate various types of frequency-dependent impedance functions by using a mechanical element called a "gyromass", a frequency-independent element defined as a unit system that generates a reaction force due to the relative acceleration of the nodes between which the gyromass is placed. This method can calculate the time-history response of inelastic structures supported by soil-foundation systems showing frequency-dependent oscillations in their impedance functions. In this study, responses of the superstructures evaluated by the GEM and by an approximate method using static impedance functions are compared. The numerical results show the tendencies of the responses of structural systems to be influenced by oscillations in the impedance functions, such that the oscillations may affect superstructures that have particular natural frequencies and yield strengths, and may affect the responses of inelastic structures more strongly than elastic structures.

000013310 7112_ $$aCOMPDYN 2009 - 2nd International Thematic Conference$$cIsland of Rhodes (GR)$$d2009-06-22 / 2009-06-24$$gCOMPDYN2009
000013310 720__ $$aSaitoh, M.
000013310 8560_ $$ffischerc@itam.cas.cz
000013310 8564_ $$s280538$$uhttps://invenio.itam.cas.cz/record/13310/files/CD456.pdf$$yOriginal version of the author's contribution as presented on CD, section: Modeling and simulations of dynamic soil- structure interaction - ii (MS).
000013310 962__ $$r13074
000013310 980__ $$aPAPER