Geotechnical Reliability Analysis Involving Spatially Autocorrelated Soil Properties

Spatial autocorrelation arises in geological material by virtue of its formation by natural processes acting over long geologic time (millions of years). This endows geomaterial with some unique statistical features (e.g. spatial variability) not commonly found in structural material manufactured under strict quality control. For example, by the...

Probabilistic VHM Failure Envelopes for Skirted Foundations in Spatially Variable, Normally Consolidated Clay

Skirted foundations are used in offshore applications to resist the large horizontal and moment loads that are characteristic of the ocean environment. The ultimate capacity of a skirted foundation subjected to vertical-horizontal-moment (VHM) loading combinations can be described using failure envelopes in VHM load space. This represents a far...

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...

Probabilistic Analysis of Velocity Distribution under Earth Embankments for Piping Investigation

Piping has been attributed as a major cause of dam and embankment failures. Current national prediction models to predict piping use the hydraulic gradient between the upstream and downstream water levels as an indicator. They are deterministic and take no account of preferential pathways. However, piping usually initiates from a discrete...

Bearing Capacity of Spatially Random Rock Masses Obeying Hoek-Brown Failure Criterion

In this paper, a probabilistic analysis is presented to compute the ultimate bearing capacity of a strip footing resting on a spatially varying rock mass. The rock is assumed to follow the generalized Hoek-Brown failure criterion. The uniaxial compressive strength of the intact rock (σc) was considered as a random field and the Geological...

Determination of Spatial Variability in d70 Grain Size Values Using High Density Site Measurements

Research to the failure mechanism piping (internal, backward erosion) in the Netherlands shows that the dikes require costly berms to meet the required safety standards. According to the Sellmeijer piping-formula, the d70 (70%-quantile of the grain size distribution by weight) is an important parameter in the resistance against piping. Therefore...

Analyzing Spatial Variability of Geologic Profiles for Four Sites in Hong Kong

This paper investigates the spatial variability characteristics of geologic profiles, including variations in thickness of marine clay deposits and rockhead levels, based on borehole data obtained from four sites in Hong Kong. The numbers of boreholes are approximately 100 in two cases, while the other two cases comprise more than 300 boreholes...

Reliability-Based Design of Spatially Variable Undrained Slopes

Spatial variability and model uncertainty are considered the major sources of geotechnical uncertainty. The primary objective of this paper is to provide slope stability investigators with a robust reliability framework that takes into consideration the combined uncertainty of spatial variability and model uncertainty. To achieve this objective,...

Spatial variability of stiffness in fiber reinforced composites in short beam shear test specimens

Modern and future aerospace structures make increasing use of fiber reinforced composite materials to optimize structural performance. Yet, characterizing the composite material properties is very expensive and time consuming. Parameters like non-linear shear and their interactions with stresses perpendicular to the fiber direction are hardly...

Advances in reliability analysis of the piping failure mechanism of flood defences in the Netherlands

Piping is one of the main failure mechanisms for flood defences. This paper gives an overview of recent developments in the reliability analysis for this mechanism in the Netherlands. These comprise new approaches in the treatment of heterogeneity of the subsoil with respect to the failure process, the inclusion of information from field...

Mining the ocean floor: Managing geological uncertainty

As land resources decrease, commodity prices increase, and technology evolves, deep sea mining is becoming a viable alternative to meet the increasing demand for minerals. Successful deep sea mining operations are built on sound identification of the resource, proper selection of equipment, a thoughtful production plan, and good project...

Slope stability analysis based on random finite element method and probabilistic approach

In this work, an investigation into generic slope stability is carried out. The investigation takes into account slope parameters of height (H) and slope gradient (?) as well as material parameters of shear strength (vc) and spatial correlation length (?). A Monte Carlo analysis of many slopes with randomly generated shear strength parameters is...

Effect of Spatial Variability on Maintenance and Repair Decisions for Concrete Structures

Due to the increasingly number of elder and deteriorating structures, maintenance is becoming a serious and more complex problem in most of the countries. A lot of studies have been carried out in this area for years. However, the fact that a lot of parameters show spatial random variability, which is linked with dependencies on temperature, w/c...

Effect of Spatial Variability on Buried Footings

Natural soil is one of the most variable materials as a result of physical and chemical changes. The variation in soil properties significantly affects the failure mechanism and bearing capacity of a footing. This effect is further complicated by considering the spatial correlation of the soil properties. The purpose of this study is to...