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Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Geo-engineering

Cascading hazards occur frequently. Unexpected casualties and losses of properties, or even impacts on the society and the environment may ensue from failure to anticipate the amplified risks induced by cascading hazards. Current risk assessment methods pay relatively less attention to quantifying the increased human risk related to “cascading” events. An improved framework for quantifying the human risk caused by cascading hazards is proposed in this paper. The framework considers the interactions among the cascading hazards and among the vulnerabilities of elements to these hazards. Its kernel is to scientifically anticipate and gear up for any new intensified hazards, which may otherwise lead to serious social aftermath. The framework is illustrated with a multi-hazard example close to the epicenter of the Wenchuan earthquake, which involved a chain of hazards including slope failures, a large debris flow, river damming, and flooding. © 2022 Elsevier B.V.

There are clear advantages in the establishment of reliable, direct cone penetration test (CPT) based methods for assessment of the axial capacity of driven piles. These advantages motivated the formation of a joint industry project (JIP) under the management of the Norwegian Geotechnical Institute (NGI), which initially led to the creation of a unified database of high-quality pile load tests in sand and clay. The unified database has the consensus approval of representatives of the profession and personnel in multiple companies from the offshore energy sector. This paper presents a component of the research from the second phase of the JIP, which had the objective of developing a new CPT-based method for driven piles in clay to unify several CPT-based methods that are in use today. First, a rational basis for the CPT-based formulation is described, using trends from instrumented pile tests; the description facilitates an understanding of the approach and illustrates its empirical nature and limitations. The unified database was used to calibrate the formulation and it led to good predictions for an independent database of pile load tests and for measured distributions of shaft friction., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Geo-engineering

This paper outlines the development of a new ‘Unified’ CPT-based method for estimating the axial capacity of driven piles in sand. The method adapts key features of the four CPT-based methods currently in the API and ISO guidelines. The new method was calibrated with the Unified database of pile load tests developed as part of an earlier joint industry research project (Lehane et al. 2017). Key factors known to influence pile capacity are incorporated in the new Unified method formulation, including (i) the degree of soil displacement (plugging) during installation, (ii) the influence of relative pile tip depth, (iii) sand-pile interface friction angle, (iv) changes in radial stress during loading and (v) the influence of loading direction. It is shown that the new method provides more reliable predictions of the capacities of the pile load tests in the Unified database than any of the existing axial pile capacity design methods in the API and ISO guidelines., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Geo-engineering

Purpose – Using risk-related data often require a significant amount of upfront work to collect, extract and transform data. In addition, the lack of a consistent data structure hinders the development of tools that can be used with more than one set of data. The purpose of this paper is to report on an effort to solve these problems through the development of extensible, internally consistent schemas for risk-related data. Design/methodology/approach – The consortia coordinated their efforts so the hazard, exposure and vulnerability schemas are compatible. Hazard data can be provided as either event footprints or stochastic catalogs. Exposure classes include buildings, infrastructure, agriculture, livestock, forestry and socio-economic data. The vulnerability component includes fragility and vulnerability functions and indicators for physical and social vulnerability. The schemas also provide the ability to define uncertainties and allow the scoring of vulnerability data for relevance and quality. Findings – As a proof of concept, the schemas were populated with data for Tanzania and with exposure data for several other countries. Research limitations/implications – The data schema and data exploration tool are open source and, if widely accepted, could become widely used by practitioners. Practical implications – A single set of hazard, exposure and vulnerability schemas will not fit all purposes. Tools will be needed to transform the data into other formats. Originality/value – This paper describes extensible, internally consistent, multi-hazard, exposure and vulnerability schemas that can be used to store disaster risk-related data and a data exploration tool that promotes data discovery and use.

Roskilde University (Denmark) hosted a November 2015 workshop, Environmental Risk—Assessing and Managing Multiple Risks in a Changing World. This Focus article presents the consensus recommendations of 30 attendees from 9 countries regarding implementation of a common currency (ecosystem services) for holistic environmental risk assessment and management; improvements to risk assessment and management in a complex, human-modified, and changing world; appropriate development of protection goals in a 2-stage process; dealing with societal issues; risk-management information needs; conducting risk assessment of risk management; and development of adaptive and flexible regulatory systems. The authors encourage both cross-disciplinary and interdisciplinary approaches to address their 10 recommendations: 1) adopt ecosystem services as a common currency for risk assessment and management; 2) consider cumulative stressors (chemical and nonchemical) and determine which dominate to best manage and restore ecosystem services; 3) fully integrate risk managers and communities of interest into the risk-assessment process; 4) fully integrate risk assessors and communities of interest into the risk-management process; 5) consider socioeconomics and increased transparency in both risk assessment and risk management; 6) recognize the ethical rights of humans and ecosystems to an adequate level of protection; 7) determine relevant reference conditions and the proper ecological context for assessments in human-modified systems; 8) assess risks and benefits to humans and the ecosystem and consider unintended consequences of management actions; 9) avoid excessive conservatism or possible underprotection resulting from sole reliance on binary, numerical benchmarks; and 10) develop adaptive risk-management and regulatory goals based on ranges of uncertainty. © 2016 SETAC, Funding: Roskilde University and their Environmental Risk Research Initiative. S. Loureiro acknowledges the financial support of CESAM (UID/AMB/50017), to FCT/MEC through national funds, and the cofunding by FEDER (POCI-01-0145-FEDER-007638), within the PT2020 Partnership Agreement and Compete 2020.

It is increasingly clear that landslides represent a major cause of economic costs and deaths in earthquakes in mountains. In the Wenchuan earthquake case, post-seismic cascading landslides continue to represent a major problem eight years on. Failure to anticipate the impact of cascading landslides could lead to unexpected losses of human lives and properties. Previous studies tended to focus on separate landslide processes, with little attention paid to the quantification of long-term evolution of multiple processes or the evolution of mass movements. The very active mass movements near the epicentre of the Wenchuan earthquake provided us a unique opportunity to understand the complex processes of the evolving cascading landslides after a strong earthquake. This study budgets the mass movements on the hillslopes and in the channels in the first eight years since the Wenchuan earthquake and verify a conservation in mass movements. A system illustrating the evolution and interactions of mass movement after a strong earthquake is proposed. © The Author(s) 2016.

In the last decades much effort has been devoted to the development of methodologies for landslide hazard and risk assessment. Although there are a few available glossaries, a review of the literature published in international journals and conferences show that the terminologies used differ greatly or are unclear. In 2011, the Joint Technical Committee nº1 of the Federation of International Geo-Engineering Societies established a working group with the objective of preparing a standard glossary of terms relevant to landslide hazard and risk. The glossary aims at an international harmonization of terms and definitions with those used in associated disciplines (i.e. seismology, hydrology, dam safety) while taking into account the specificity of landslides. The glossary takes as starting point previous glossaries prepared by the ISSMGE TC32 and UNISDR., Postprint (published version)

Glacier- and permafrost-related hazards represent a continuous threat to human lives and infrastructure in high mountain regions. Because the surface and subsurface ice involved is generally close to melting conditions, glacier and permafrost hazards are particularly sensitive to climate changes. The present shift of cryospheric hazard zones due to atmospheric warming, process interactions and chain reactions, and the potential far reach of glacier disasters make it necessary to apply modern remote sensing techniques for the assessment of glacier and permafrost hazards in high mountains. In this contribution we provide an overview of different hazard types and how air- and space-borne remote sensing methods can be applied for their assessment.

Society requires increasingly that the hazard and risk associated with engineered constructions be quantified. The paper presents ge-otechnical hazard assessment in the context of a risk framework. Concepts of uncertainties, reliability, safety and risk are briefly re-viewed. The use of the approach is exemplified for offshore facilities, including a piled foundation, a gravity foundation, a jack-up structure and underwater slopes. The applications demonstrate that probabilistic analyses complement the conventional deterministic safety factor and deformation-based analyses, and contribute to achieving a safer and optimum design. The conclusions emphasize the usefulness of a risk assessment, the importance of engineering judgment in the assessment and the need for involving multi-disciplinary competences to achieve reliable estimates of hazard and risk. The profession can only gain by implementing more sys-tematically than before probabilistic-based thinking and risk-based approaches.

A case history of the foundation behaviour of an offshore gravity base structure (GBS) is presented. The platform rests on an overconsolidated fissured clay, bounded, top and bottom, by pervious sand layers. Sixteen piezometers have been placed within this 30 m layer. Based on one-dimensional consolidation theory, independent analyses using both settlement and pore pressure measurements indicated a high degree of consolidation had occurred much sooner than was estimated in the initial design phase. These analyses indicated that laboratory oedometer tests underpredicted the coefficient of consolidation by one to two orders of magnitude. Updated settlements and stability analyses yielded 50% of the initially anticipated settlement and a 20% increase in the available safety factor. In addition, the certainty that the theory relating pore pressure to settlements was appropriate, led to confidence in the piezometer performance, and in turn the procedure used to install them.

The geological profile of submerged slopes on the continental shelf typically includes soft cohesive soils with layer thicknesses ranging from a few meters to tens or hundreds of meters. The response of these soils in simple shear tests is largely influenced by the presence of an initial consolidation shear stress, inducing anisotropic stress-strain-strength properties which depend also on the direction of shear. In this paper, a new simplified effective-stress-based model describing the behavior of normally to lightly overconsolidated cohesive soils is used in conjunction with a one-dimensional seismic site response analysis computer code to illustrate the importance of accounting for anisotropy, small strain nonlinearity and pore pressure development. In particular, a simple example is carried out to compare results for level ground conditions and a 10° slope. Depth profiling of the maximum shear strains and permanent deformations provide insight into the mechanisms of deformation during a seismic event, and the effects of sloping ground conditions.

The parameters determined in laboratory tests for use in dynamic analyses are usually the secant modulus and the area of the hysteresis loop. The accuracy of this approach was studied for highly non-linear behavior through analytical solutions and numerical simulations of a single degree of freedom system. Only the effect of the shape of the hysteresis loop was studied, i.e. the stiffness and the area of the loop were kept constant independent of amplitude. The study shows that irregular hysteresis may cause a significant increase in the response of the system in higher frequencies compared to what would be expected from visco-elastic and standard non-linear models. The area of the hysteresis loop provides a good measure of the damping also for high degrees of non-linearity.

The paper makes a brief review of the state-of-the-art in marine geotechnics. The design problems for different offshore foundation types, from traditional piled and gravity base foundations to the new lightweight skirted foundation concepts, are described. Geotechnical breakthroughs have enabled new and daring constructions offshore and opened the way to cost-effective solutions. At the same time, the requirements and conditions imposed by the offshore industry also greatly contributed to an improved understanding of the behavior of soils under new loading conditions. The paper looks into the development of enhanced site investigations and soil characterization, model testing, improved design methods and new foundation solutions. The challenges facing the geotechnical engineering profession when moving into deeper waters and the steps needed to meet these challenges are outlined.

Statistics, reliability analyses and risk estimates can be very useful decision-making tools in geotechnical problems. Yet the methods are little used in practice. The offshore and mining industry are at the forefront for the use of these approaches, having encouraged their use and sponsored research that has enabled the methods to be well-documented and of proven usefulness in the study of alternatives for design and decision-making in face of uncertainties. The paper presents a few case studies in different areas of geotechnical engineering and discusses the results that would have been obtained without the use of the risk approach. Special emphasis is given to dams and offshore structures, both piled and shallow foundations. The authors take a look at the reasons why the methods are not used to a greater extent in practice and make recommendations as to when and how one should uses such methods.