Application of Conditional Random Fields and Sparse Polynomial Chaos Expansions to Geotechnical Problems

In geotechnical applications, mechanical properties of soil vary spatially within the soil mass and they are often represented by random fields. When data at certain locations of the soil mass are available, conditional random fields may be used to incorporate them. In this paper, we combine conditional random fields with sparse polynomial chaos...

Probabilistic Analysis at Ultimate Limit State of Strip Footings Resting on a Spatially Varying Soil Using Subset Simulation Approach

The failure probability of geotechnical structures with spatially varying soil properties is generally computed using Monte Carlo simulation (MCS) methodology. This approach is well known to be very time-consuming when dealing with small failure probabilities. One alternative to MCS is the subset simulation approach. This approach was mainly...

Computing the Reliability of Shallow Foundations with Spatially Distributed Measurements

In many geotechnical projects, field data is used to determine the soil parameters. In most instances, however, the statistical analysis is performed ad hoc and the spatial distribution of this data is not (expclitly) accounted for. A more formal statistical approach allows to make better use of the data and combine it in a consistent manner...

Scale of Fluctuation for Geotechnical Probabilistic Analysis

In the past few years, random field theory has been increasingly used to model the inherent soil variability. The scale of fluctuation is one of the important parameters describing a stationary random field. In this study, the factors affecting an accurate estimation of the scale of fluctuation were studied with numerical experiments to show how...

System Failure Probability of c-φ Soil Slope Stability using Vertical Random Fields

The need for system failure probability, pf , of soil slope stability that takes into account the spatial variation of soil properties has been acknowledged by the geotechnical profession. The spatial variations of cohesion and friction angle for a c-ϕ soil slope were modeled by one dimensional vertical random field respectively. The cross...

Stability Analysis of Unsaturated Soil Slope Considering the Variability of Soil-water Characteristic Curve

Soil slopes are generally unsaturated in which the soil-water characteristic curve (SWCC) plays an important role in its hydro-mechanical response. The commonly used Mohr-Coulomb failure criterion in saturated soil mechanics could be extended to take SWCC into account which is then able to determine the shear strength of unsaturated soil. Like...

Safety assessment of a shallow foundation using the random finite element method

In this paper, the reliability assessment of the bearing capacity of a shallow strip footing was conducted using a reliability index β. In applicable standards (Eurocode 7) there is not presented any explicit method of an evaluation of characteristic values of soil parameters. Therefore some approaches of an estimation of characteristic values...

Accounting for Uncertainty and Variability in Geotechnical Characterization of Offshore Sites

This paper presents an overview on how uncertainty and variability of mechanical soil properties are dealt with in offshore site investigation and presents some ideas for utilizing the reliability tools in a more optimal manner for this purpose. Two types of problems are addressed. First, how to extract the maximum amount of information from...

Probabilistic Slope Stability Analysis using RFEM with Non-Stationary Random Fields

Using recently obtained deterministic results as a benchmark, probabilistic slope stability analyses have been performed on an undrained slope using the random finite element method (RFEM). Non-stationary random fields have been generated with linearly increasing mean undrained strength and a constant coefficient of variation. The influence of...