Description
The NTUA-SAND model comprises a reversal surface model within the SANISAND framework of constitutive models for sands, whose main characteristic is the inter-dependence of the critical state, the bounding and the dilatancy (open cone) surfaces on the basis of the state parameter. In addition, it employs a (Ramberg–Osgood type) non-linear hysteretic formulation for the ‘‘elastic’’ strain rate and an empirical index of the directional effect of sand fabric evolution during shearing, which scales the plastic modulus. It requires the calibration of 13 model constants (2 of which are not required for monotonic loading). The model is proposed for analysis and design of geostructures in a seismic liquefaction regime, since it has been shown to accurately predict the response in widely different boundary value problems involving seismic liquefaction, with the same set of model constants calibrated on the basis of laboratory element tests.
Keywords
- bounding surface
- critical state
- effective stress
- liquefaction
- plastic
- pore pressure
- seismic loading
- state parameter
- stress-strain analysis
References
Andrianopoulos K. I., Papadimitriou A. G., Bouckovalas G. D. (2010), “Explicit integration of bounding surface model for the analysis of earthquake soil liquefaction”, International Journal for Numerical and Analytical Methods in Geomechanics, 34 (15): 1586-1614.
Andrianopoulos K. I., Papadimitriou A. G., Bouckovalas G. D. (2010), “Bounding surface plasticity model for the seismic liquefaction analysis of geostructures”, Soil Dynamics and Earthquake Engineering, 30(10): 895-911.
Papadimitriou A. G., Bouckovalas G. D., Dafalias Y. F. (2001), “Plasticity model for sand under small and large cyclic strains”, Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 127(11): 973-983.
Papadimitriou A. G., Bouckovalas G. D. (2002), “Plasticity model for sand under small and large cyclic strains: a multiaxial formulation”, Soil Dynamics and Earthquake Engineering, 22: 191-204.
Bouckovalas G., Tsiapas Y, Theocharis A., Chaloulos Y. (2017), “Ground response at liquefied sites: seismic isolation or amplification?”, Soil Dynamics and Earthquake Engineering (in press).
Andrianopoulos K., Agapoulaki G., Papadimitriou A. (2016), “Simulation of seismic response of passively stabilised sand”, Geotechnical Research 3 (2), 40-53.
Chaloulos Y., Bouckovalas G., Karamitros D. (2013), “Pile response in submerged lateral spreads: common pitfalls of numerical and physical modeling techniques”, Soil Dynamics and Earthquake Engineering 55, 275-287.
Karamitros D., Bouckovalas G., Chaloulos Y. (2013), “Insight into the seismic liquefaction performance of shallow foundations”, Journal of Geotechnical and Geoenvironmental Engineering 139 (4), 599-607.
Bouckovalas G., Papadimitriou A., Niarchos D., Tsiapas Y. (2011), "Sand fabric evolution effects on drain design for liquefaction mitigation", Soil Dynamics and Earthquake Engineering, 31(10): 1426-1439.
Valsamis A., Bouckovalas G., Papadimitriou A. (2010), "Parametric investigation of lateral spreading of gently sloping ground", Soil Dynamics and Earthquake Engineering, 30: 490-508.