Norwegian Geotechnical Institute (NGI) Digital Archive
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Vibration induced damage due to construction work – Blasting tests
Get PDFIn this study, two instrumented blast test series were performed in a rock quarry in Norway. For the first test series, two buildings were erected, one made of Light Expanded Clay Aggregate (Leca) blocks, and one in cast-in-place unreinforced concrete. Both buildings were founded on a thin compacted gravel layer over rock. In the second test series one building made of Leca blocks was erected on top of an about 4 m thick filling, established at the same location as the buildings in the first test series. The test buildings were instrumented with triaxial geophones, accelerometers and Fiber Bragg Grating Sensors (strain sensors) in multiple positions. To gain full control, repeatability and traceability of the blasts, packaged emulsion and NG-based explosives
together with electronic detonators were used
Hydro-Mechanical Effects of Several Riparian Vegetation Combinations on the Streambank Stability — A Benchmark Case in Southeastern Norway
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3D FE-Informed Laboratory Soil Testing for the Design of Offshore Wind Turbine Monopiles
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Metoder, verktøy og arbeidsflyt for risikovurdering av planlagte deponilokaliteter på Svalbard
Get PDFProsjektet "Permafrost som geologisk barriere", finansiert gjennom Svalbard Miljøvernfond, har som målsetning å forstå i hvilken grad permafrost er en fungerende geologisk barriere i tilknytning til deponier på Svalbard. Dette gjelder både eksisterende deponier for avfall fra lokalsamfunn og gruvevirksomhet, samt planlegging av fremtidige deponier. Prosjektets mål er å etablere et verktøy for hvordan man best kan utføre en miljørisikovurdering med tanke på valg av fremtidige deponilokaliteter i områdene rundt bosetningene på Svalbard. Dette krever en integrering av ulike faktorer som vil være kritisk for den langsiktige risiko et deponi vil kunne utgjøre: Fremtidig klima som forventes å bli varmere i arktiske strøk. Permafrostens tilstand og utbredelse. Skredfare (snø, sørpe, stein) i terrenget. Geoteknisk stabilitet av grunnen. Hydrologiske og hydrogeologiske forhold. Avfallskarakterisering.
Et verktøy er utviklet som integrerer mulige risikomomenter som er styrt av både fysiske, kjemiske og biologiske faktorer. Metodikken for risikovurdering gjør det mulig å integrere disse ulike aspekter i en kvalitativ risikovurdering. Dette gjør det mulig å vurdere ulike deponilokaliteter i forhold til hverandre, både med hensyn til eksisterende og potensiell fremtidig risiko. Det gjøres oppmerksom på at verktøyet har fokus på deponiets livsfase som omfatter drift, avslutning og etterdrift. Risiko ved prosjektering og etablering av deponiet er ikke omfattet av verktøyet som presenteres her.
Risiko og sårbarhetsanalyse legges til grunn i metodikken som omfatter følgende trinn: Risikoidentifikasjon: Hva kan gå galt? Risikoanalyse: Hva er sannsynligheten for at det går galt? Hva er konsekvensen av at det går galt? Risikoevaluering: Er risikoen akseptabel?
Det er definert 5 sannsynlighetsklasser og 5 konsekvensklasser i risikoanalysefasen. Dette fører til en 5 x 5 risikomatrise som danner grunnlaget for risikoevalueringen. Basert på evalueringen vurderes risikoen til å være lav, middels eller høy med resulterende behov/ikke behov for tiltak til å redusere risikoen.
Metodikken har blitt anvendt på et planlagt fremtidig deponi for skeidestein, aske og slagg i Barentsburg der NGI har utført innledende undersøkelser i 2018.
Utprøving viser at metodikken er egnet til å identifisere de lokale forhold som er kritisk for langsiktig lagring av avfall og overskuddsmasser. Dette vil være styrende for kvantitative studier som legges til grunn for detaljdesign av deponier.Svalbard Miljøvernfon
Implementing nature-based solutions in rural landscapes: Barriers experienced in the phusicos project
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OC6 Phase II: Integration and verification of a new soil–structure interaction model for offshore wind design
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A review of the testing approaches in swelling rock conditions at three different institutions
Get PDFThe swelling potential of weak rocks is crucial to assess in stability determinations of tunnels constructed for both infrastructure and hydropower. Among the institutions that are involved with extensive research on swelling rock material, the methodologies applied at three different European institutions are reviewed in this manuscript. XRD analysis and oedometer swelling tests are included as index tests at all three institutions whereby the adopted swelling test methodologies at all three institutions are grounded in the ISRM standards. Different mindsets in how to forecast the challenges related to swelling are, however, reflected in the boundary conditions of test procedures and the internal modifications on the test apparatus, the preparation procedure, and in the choice of specimen size/mass. This manuscript reviews the adopted methodologies and highlights the advantages and drawbacks on the testing approaches used. Two of the institutions rely on a general approach which is standardized, and the results are compared. It is highlighted that, both institutions have modified the ISRM standard and the methodologies represents two unique approaches. Institution 3 have a case-specific approach and no test data were available. However, the described methodology differs from the procedures at Institution 1 and 2. Important differences between the testing procedures are both discussed and exemplified by comparing the test results obtained from duplicate samples at two of the institutions.publishedVersio
Early Miocene carbonate ramp development in a warm ocean, North West Shelf, Australia
Get PDFAlthough carbonate ramps are widely described from the geological record,there is still a debate on the relative influence of water temperature, trophicconditions and type of carbonate factories on their development. Theca2400 km long Australian North West Shelf is among the largest Cenozoic car-bonate provinces worldwide, and records a transition from an early Mioceneramp to a middle Miocene rimmed platform. This change is observable onpublicly available seismic data, giving the opportunity to investigate envi-ronmental influences on platform evolution. This study combines macro-scopic and petrographic descriptions of early Miocene strata cropping out inthe Cape Range Anticline (North West Cape, southern end of the North WestShelf) and of time-equivalent well cuttings from the adjacent, offshoreExmouth Sub-basin. Particular emphasis is placed on the identification oflarger benthic foraminifera at a broad generic level, because differing taxahave a limited range of habitable conditions that serve as environmentalproxies. The results show that early Miocene strata are dominantly com-posed of larger benthic foraminifera with minor coralline algae in the proxi-mal platform, grading to micropackstones in the more distal platform. Aramp margin is inferred from the lithological data on the basis of the lack offramework builders and the presence of open oceanic indicators. Facies shal-low upward through individual outcrops, with a proximal to distal trendtowards the north-west. These trends along outcrops are consistent with theseismic interpretations. Identification of taxa with warm, oligotrophic wateraffinity suggests that the ramp was formed in an oligotrophic and warmocean, despite the absence of coral reefs. Changes of carbonate facies withdepth do not seem to be associated with changes in ramp morphology, andthe latter may have been controlled by physical oceanic parameters, such asoffshore currents and waves.Early Miocene carbonate ramp development in a warm ocean, North West Shelf, AustraliapublishedVersio
Stability of the Gunneklev Fjord sediments
Get PDFThe seabed of the Gunneklev Fjord, with exceptionally soft contaminated sediment, is to be capped. The sediment, containing, among others, mercury and dioxins mixed with natural mud, has an undrained shear strength less than 1 kPa and thickness up to 2.5 m. To reduce the potential for leaching of mercury and dioxin from these sediments, Hydro Energy AS developed a remediation plan for Gunneklev Fjord which includes capping of the contaminated sediment with either sand or a mixture of sand and active charcoal. This paper presents an assessment of the risk associated with the cap placement over the contaminated sediment. The potential for the cap causing sliding of the sediment, which could re-expose even more severely contaminated layers and spread the contaminated material, was analysed deterministically and probabilistically. The sediment's undrained shear strength and thickness and the cap thickness were modelled as random variables. The deterministic analyses gave a safety factor over 3. The probabilistic analyses indicated, however, that the probability of sliding can be high for areas where the seabed inclination is steeper than 1:50, and if the average undrained shear strength is less than 0.4 kPa. The analyses highlight the importance of careful cap placement on the sloping seabed of the fjord, and the need to control the cap thickness. The analyses were used to support decision-making on the design of the cap and the placement method.publishedVersio
