http://www.ukm.my/kamal3/psm/pfpstochastics.pdf

The stochastic finite element method: Past, present and future

This paper presents a review of the current state-of-the-art of numerical methods for stochastic computations. The focus is on efficient high-order methods suitable for practical applications, with a particular emphasis on those based on generalized polynomial chaos (gPC) methodology. The framework of gPC is reviewed, along with its Galerkin and collocation approaches for solving stochastic equations. Properties of these methods are summarized by using results from literature. This paper also attempts to present the gPC based methods in a unified framework based on an extension of the classical spectral methods into multi-dimensional random spaces. AMS subject classifications: 41A10, 60H35, 65C30, 65C50

/pdf/fast-numerical-methods-for-stochastic-computations-a-review-8t3n840kw5.pdf

Fast numerical methods for stochastic computations: A review

More than 100 offshore mass-movement deposits have been studied in Holocene and Pleistocene sediments. The processes can be divided into three main types: slides/slumps, plastic flows, and turbidity currents, of which 13 main varieties have been recognized. The three types are differentiated mainly by motion, architecture, and shape of failure surface. For slides, the morphology of deposits can usually be linked to a process, but for plastic flows and turbidity currents, information about the motion is mainly provided by the sedimentary record. A static classification based on these features is given, and is related to a dynamic classification system to try to underline the morphological transformation of an offshore event from initiation to deposition.

Classification of offshore mass movements

Scientific approaches to pile design have advanced enormously in recent decades and yet, still, the most fundamental aspect of pile design—that of estimating the axial capacity—relies heavily upon empirical correlations. Improvements have been made in identifying the processes that occur within the critical zone of soil immediately surrounding the pile, but quantification of the changes in stress and fabric is not straightforward. This paper addresses the degree of confidence we can now place (a) on the conceptual and analytical frameworks for estimating pile capacity, and (b) on the quantitative parameters required to achieve a design. The discussion is restricted to driven piles in clays and siliceous sands, with particular attention given to extrapolating from design approaches derived for closed-ended piles of relatively small diameter to the large-diameter open-ended piles that are used routinely in the offshore industry. From a practical viewpoint, we need design approaches that minimise sensitivity...

Science and empiricism in pile foundation design

Shape memory alloys (SMAs) are a class of alloys that possess numerous unique characteristics. They offer complete shape recovery after experiencing large strains, energy dissipation through hysteresis of response, excellent resistance to corrosion, high fatigue resistance, and high strength. These features of SMAs, which can be exploited for the use in control of civil structures subjected to seismic events, have attracted the interest of many researchers in structural engineering over the past decades. This article presents an extensive review of seismic applications of SMAs. First, a basic description of two unique effects of SMAs, namely shape memory and superelastic effect, is provided. Then, the mechanical characteristics of the most commonly used SMAs are discussed. Next, the material models proposed to capture the response of SMAs in seismic applications are briefly introduced. Finally, applications of SMAs to buildings and bridges to improve seismic response are thoroughly reviewed.

Seismic Response Control Using Shape Memory Alloys: A Review

Effects of random heterogeneity of soil properties on bearing capacity

The effects of spatial variability of soil properties on the behaviour of saturated soil deposits subjected to seismic excitation are analysed, and their implications for geotechnical design are discussed. A Monte Carlo simulation methodology, combining digital generation of non-Gaussian stochastic vector fields with dynamic, nonlinear finite element analyses, is used for that purpose. The proposed procedure is applied to assess the soil liquefaction potential, which is found to be considerably affected by the inherent spatial variability of soil properties. Parametric studies, involving the degree of soil liquefaction and the frequency content of the seismic input, are performed. Finally, a characteristic percentile value of soil strength, which will predict a response equivalent to that provided by the more expensive Monte Carlo simulations, is proposed for use in deterministic design.

Radu Popescu

Papers

Effects of random heterogeneity of soil properties on bearing capacity

Effects of spatial variability on soil liquefaction: some design recommendations

Simulation of homogeneous nonGaussian stochastic vector fields

Centrifuge validation of a numerical model for dynamic soil liquefaction

Dynamics of nonlinear porous media with applications to soil liquefaction