Journal ArticleDOI
Normalized shear modulus and material damping ratio relationships
TLDR
In this article, a modified hyperbolic model and a statistical analysis of existing Resonant Column and Torsional Shear test results for 122 specimens obtained from South Carolina, North Carolina, and Alabama are presented.Abstract:
Predictive equations for estimating normalized shear modulus and material damping ratio of Quaternary, Tertiary and older, and residual/saprolite soils are presented in this paper. The equations are based on a modified hyperbolic model and a statistical analysis of existing Resonant Column and Torsional Shear test results for 122 specimens obtained from South Carolina, North Carolina, and Alabama. Variables used in the equations for normalized shear modulus are: shear-strain amplitude, confining stress, and plasticity index (PI). The equations for damping ratio are expressed in terms of a polynomial function of normalized shear modulus plus a minimum damping ratio. It is found that the Quaternary soils exhibit more linearity than soils of the other two groups. Also, it is found that the effect of PI on dynamic soil behavior is not as significant as previously thought. Data from all three groups exhibit significant variations with confining stress, similar to the variations determined by Stokoe et al. The uncertainties associated with the equations for PI of 0 and mean effective confining stress of 100 kPa are quantified using the point estimate method. A case study from Charleston, S.C. is provided to illustrate an application of the equations to seismic response analysis and the importance of considering confining stress and geologic age.read more
Citations
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Journal ArticleDOI
Damping formulation for nonlinear 1D site response analyses
TL;DR: In this article, the authors presented two new soil damping formulations implemented in nonlinear one-dimensional site response analysis for small and large strains, which were used separately and simultaneously in non-linear site response analyses.
Journal ArticleDOI
Stiffness of clays and silts: Normalizing shear modulus and shear strain
TL;DR: In this paper, an analysis is presented of a database of 67 tests on 21 clays and silts of undrained shear stress-strain data of fine-grained soils, and a simple expression that uses only a void-ratio function and a confining-stress function is proposed.
Journal ArticleDOI
A review of foundations of offshore wind energy convertors: Current status and future perspectives
TL;DR: In this article, a review of foundations for offshore wind energy convertors considering the significant growth of offshore wind power since the early 2000s is presented, where the characteristics of various foundation types (i.e., gravity, pile, suction caisson, and float type) and current status of field application are discussed.
Journal ArticleDOI
Critical Parameters Affecting Bias and Variability in Site‐Response Analyses Using KiK‐net Downhole Array Data
TL;DR: In this article, the authors performed linear and equivalent linear site-response analyses at 100 Kiba-Kyoshin network (KiK-net) sites using 3,000 ground motions ranging in amplitude from weak to strong.
Journal ArticleDOI
Comparison of 1D linear, equivalent-linear, and nonlinear site response models at six KiK-net validation sites
TL;DR: In this article, a comprehensive linear, equivalent-linear, and nonlinear site response analyses of 191 ground motions recorded at six validation sites in the Kiban-Kyoshin network (KiK-net) of vertical seismometer arrays in Japan were performed.
References
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Journal ArticleDOI
New Empirical Relationships among Magnitude, Rupture Length, Rupture Width, Rupture Area, and Surface Displacement
TL;DR: In this article, a series of empirical relationships among moment magnitude (M ), surface rupture length, subsurface rupture length and downdip rupture width, and average surface displacement per event are developed.
Journal ArticleDOI
Shear modulus and damping in soils: design equations and curves
TL;DR: In this paper, an equation and graph for the determination of shear modulus and damping of soils for use in design problems involving repeated loading or vibration of soils, are presented.
Journal ArticleDOI
Effect of Soil Plasticity on Cyclic Response
Mladen Vucetic,Ricardo Dobry +1 more
TL;DR: In this article, a study on the influence of the plasticity index (PI) on the cyclic stress-strain parameters of saturated soils needed for site response evaluations and seismic microzonation is presented.