3 research outputs found
Modelling of non-linear seismic ground response using elasto-plastic constitutive framework within a finite element soil column model
No full textThe prediction of seismic ground response is conditioned by the knowledge of each material behavior of soil deposits. The recourse to plasticity criterion to simulate cyclic behavior of soils under seismic loading is becoming more realistic. In this study, an elasto-plastic constitutive equation is cast within the framework of one dimensional finite element (FE) soil column model to account for the spatial and material nonlinearity of the secant shear modulus. To account of the spatial non linearity, shear modulus is written in terms of rigid base shear modulus and height of the soil column, while for material nonlinearity, the shear modulus degradation is deducted by the application of the isotropic evolution of the Von Misès criterion. Obtained results proved the efficiency of the proposed methodology and the predictive capability of the elaborated elastoplastic model which captures both small- and large-strain behaviors. They likewise highlight the important roles that play the spatial and material shear modulus variation in the prediction of the seismic soil responses.</jats:p
Non-linear soil modelling by correction of the hysteretic damping using a modified Iwan model together with Masing rules
No full textStiffness-and damping-strain curves of sensitive Champlain clays through experimental and analytical approaches
No full textStiffness degradation curves of Champlain clay at St-Adelphe, QuĂŠbec and the associated variation of its damping ratio with shear strain are constructed in this paper using the new combined triaxial simple shear (TxSS) apparatus. The apparatus offers the ability to obtain the stiffness and damping ratio of soils over a wide range of strain spectrum from 0.001% to 10%. The value of the small-strain stiffness of the tested clay is further confirmed through another series of piezoelectric ring-actuator technique (P-RAT) tests. Although, the stiffness degradation curve of the tested clay follows to some extent traditional curves suggested in literature, the examined Champlain clay exhibits different trend with respect to hysteresis damping especially at large strains (>1%) and available analytical models couldnâ t successfully predict the damping behavior of the Champlain clay at such strain level. A new constitutive model is therefore presented as a modification of the original Sig4 model considering the pore water pressure built-up with shear strain. Stiffness degradation and damping ratio versus shear strain curves of Champlain clays estimated using the proposed soil model are compared successfully with their experimentally-determined counterparts even at large shear strains where other models tend to misjudge the damping behavior of the clay.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
