Computational geomechanics: The heritage of Olek Zienkiewicz

Abstract

SUMMARYGeotechnical engineering design is based on mathematical, constitutive and numerical models implemented in computer codes which are able to predict the behaviour of geostructures and foundations under a wide variety of loading conditions, sometimes demanding or extreme. Prediction is fundamental in areas such as seismic engineering, marine foundations or landslide hazard analysis. No computer code is better than the mathematical, constitutive and numerical models which it implements. This paper is devoted to (i) reviewing the decisive contributions of Professor Olek Zienkiewicz to the development of mathematical, constitutive and numerical models in geotechnical engineering and (ii) presenting some extensions based on his work which have been proposed by the authors. The extensions to be described here are the following: (i) a particularization of the u − p w Zienkiewicz model to the case of fast catastrophic landslides (ii) an extension of the generalized plasticity model proposed by him and (iii) an SPH numerical model for the propagation of fast catastrophic landslides.

Seismic dynamics of offshore breakwater on liquefiable seabed foundation

“…The dynamic behavior of the seabed soil is modeled by using a validated soil constitutive model-Pastor-Zienkiewics Mark III (PZIII) [17,37]. In this investigation, variation of void ratio of the seabed soil and its corresponding permeability, as well as the hydrostatic pressure acting on the surface of seabed and offshore breakwater are updated in each time step in accordance to the seismically induced displacement of offshore breakwater and deformation of the seabed foundation.…”

Computational monitoring in real time: review of methods and applications

“…It has been used in numerous computational geomechanics studies (Dysli 1983;Broyden 1984;Bardet 1990;Auvinet et al 1996;Moresi et al 2003;Yue et al 2003;Kardani et al 2013) with important contributions from O.C. Zienkiewicz, one of the founders of finite element method (Zienkiewicz et al 1970(Zienkiewicz et al , 1999) (Pastor et al 2011).…”

“…It utilises a strong form of equations of continuum mechanics (Gingold and Monaghan 1977;Lucy 1977;Monaghan 1992). The SPH (often in combination with DEM) has been applied in geomechanics to model ductile failure and hydrofracturing (Komoroczi et al 2013), rock blasting (Fakhimi and Lanari 2014), intersecting discontinuities and joints in geomaterials (Pramanik and Deb 2015), fast landslides (Clearly and Prakash 2004;Pastor et al 2011), geophysical flows (Clearly and Prakash 2004) and fluidised soils (Rodriguez-Paz and Bonet 2005;Pastor et al 2009). However, several important shortcomings of the SPH method such as instabilities in tension and the accuracy inferior to that of the finite element method, have been recognised in the literature .…”

Meta-modeling game for deriving theory-consistent, microstructure-based traction–separation laws via deep reinforcement learning

“…In the second example, we consider another common scenario in which we attempt to convert qualitative observations into quantitative predictions with the help of the reinforcement learning algo- rithm as a tool for augmented intelligence. The need to interpret observations of mechanisms into predictions is one of the oldest problems in constitutive modeling [Pastor et al, 2011]. For instance, the observation that yielding depends on the amount of normal traction leads to the Mohr-Coulomb yield criterion [Timoshenko, 1953].…”