• A Laboratory Study of Salt Diffusion and its Effect on Electrical Resistivity and Sensitivity in Quick Clay 

      Øveraas, Astrid Thorvik (Master thesis, 2016)
      Resistivity measurements as a geophysical method have become increasingly popular as a supplement to geotechnical field investigations over the last years. The main use for this method is to uncover the possibility of quick ...
    • A macro model for shallow foundations on granular soils describing non-linear foundation behavior 

      Tistel, Joar; Grimstad, Gustav; Eiksund, Gudmund Reidar (Journal article; Peer reviewed, 2017)
      This paper describes a macro model for a shallow foundation. The macro model represents the non-linear soil structure interaction (SSI) exemplified by a suspension bridge anchor-block. The model can be adjusted and used ...
    • A macro-element for integrated time domain analyses representing bucket foundations for offshore wind turbines 

      Skau, Kristoffer Skjolden; Grimstad, Gustav; Page, Ana M.; Eiksund, Gudmund Reidar; Jostad, Hans Petter (Journal article; Peer reviewed, 2018)
      The paper presents a macro-element model for bucket foundations to be used in integrated time domain analyses of offshore wind turbines. The macro-element has been formulated in the multi-surface plasticity framework, and ...
    • A macro-element model for multidirectional cyclic lateral loading of monopiles in clay 

      Page, Ana M.; Grimstad, Gustav; Eiksund, Gudmund Reidar; Jostad, Hans Petter (Journal article; Peer reviewed, 2018)
      This paper investigates numerically the impact of multidirectional cyclic loads on the response of a monopile in clay supporting an offshore wind turbine (OWT). The results indicate that multidirectional loading modifies ...
    • A macro-element pile foundation model for integrated analyses of monopilebased offshore wind turbines 

      Page, Ana M.; Grimstad, Gustav; Eiksund, Gudmund Reidar; Jostad, Hans Petter (Journal article; Peer reviewed, 2018)
      The design of OWTs relies on integrated load analyses tools that simulate the response of the entire OWT (including the rotor-nacelle assembly, support structure and foundation) under combined aerodynamic and hydrodynamic ...
    • A numerical investigation of strain-softening in soft clay for a modelled shear vane 

      Henneseid, Olav (Master thesis, 2018)
      The strain-softening phenomenon has been extensively studied the last decades in context of numerical modelling and progressive failure mechanism. In this study, a vane is modelled in soft clay with a negative dilatancy. ...
    • An anisotropic shear strength model for cyclic accumulated plastic strain of overconsolidated clay 

      Cai, Fang; Eiksund, Gudmund Reidar; Grimstad, Gustav; Jostad, Hans Petter (Journal article; Peer reviewed, 2014)
      Many geotechnical problems involve calculation of the permanent deformation of overconsolidated clay under undrained cyclic loading. There are many existing methods in the literature which have been made for predicting ...
    • An Effective Stress Based Model for Undrained Slope Stability Analyses in Anisotropic Clay 

      Aamodt, Magnus Træland (Master thesis, 2019)
      Direkte skjærtester (DSS) utført på naturlig myk leire indikerer at skjærstyrken vil øke dersom leiren konsolideres under en skjærspenning (Andersen, 2009). Formålet med denne studien er å avgjøre om anisotrop skjærstyrke ...
    • An elastic-viscoplastic model for saturated frozen soils 

      Ghoreishian Amiri, Seyed Ali; Grimstad, Gustav; Kadivar, Mehdi (Journal article; Peer reviewed, 2017)
      From the material science point of view, saturated frozen soil is a natural particulate composite, composed of solid grains, ice and unfrozen water. The mechanical behaviour of such a material is strongly affected by the ...
    • An experimental study of thermal properties and the influence on the ground thermal regime in permafrost soil 

      Eiken, Idun (Master thesis, 2019)
      Jord er et porøst materiale som består av mineralkorn og porer som er fylt med luft og vann. Frossen jord har høy trykkstyrke og høy bæreevne. Infrastruktur som er etablert i områder med permafrost er avhengig av styrken ...
    • An Experimental Study of Thermal Properties of Permafrost Soils 

      Bratlie, Una Helene Haug (Master thesis, 2018)
      Soil is a multiphase porous media, and its complexity increases when the soil freezes. The high compressive strength of frozen soil has been utilized by geotechnical engineers in construction of frozen earth structures. ...
    • An experimental study of unfrozen water content in fine grained permafrost soils 

      Nybo, Marte Sundby (Master thesis, 2017)
      The strength of a soil increases when the ground freezes, but some of the water will remain unfrozen. Unfrozen water content is an important thermal property of a soil as flowing water may supply heat, reduce the strength, ...
    • Application of a generalized continuous Mohr–Coulomb criterion 

      Grimstad, Gustav; Rønningen, Jon Abusland; Nordal, Steinar (Chapter, 2018)
      This paper presents an application of a generalized failure criterion for soils. The presented formulation was originally adopted by the authors to round the corners of the Mohr–Coulomb (MC) yield surface in principals ...
    • Comparison of Geoacoustic Models for Unfrozen Water Content Estimation 

      Lyu, Chuangxin; Ghoreishian Amiri, Seyed Ali; Grimstad, Gustav; Høyland, Knut Vilhelm; Ingeman-Nielsen, Thomas (Peer reviewed; Journal article, 2020)
      This paper reviews eight geoacoustic models applied to frozen soils: crystal growth models (grain cementing, grain coating, matrix supporting, and pore filling), the weighted equation (WE) model, Zimmerman and King's model ...
    • Constitutive Model for Long-Term Behavior of Saturated Frozen Soil 

      Ghoreishian Amiri, Seyed Ali; Grimstad, Gustav (Chapter, 2017)
      In this paper a two stress-state variables model with solid phase stress and cryogenic suction is introduced for simulating the long-term behavior of frozen soils. The solid phase stress is introduced as the combined stress ...
    • Creep of geomaterials – some finding from the EU project CREEP 

      Grimstad, Gustav; Karstunen, Minna; Jostad, Hans Petter; Sivasithamparam, Nallathamby; Mehli, Magne; Zwanenburg, Cor; Evert, den Haan; Ghoreishian Amiri, Seyed Ali; Boumezerane, Djamalddine; Kadivar, Mehdi; Haji Ashrafi, Mohammad Ali; Rønningen, Jon A. (Journal article; Peer reviewed, 2017)
      This paper gives a summary of some of the main findings of the EU founded project “Creep of geomaterials”, CREEP. CREEP was an Industry-Academia Partnerships and Pathways (IAPP) project funded from the 7th Framework Programme ...
    • Cyclic Behaviour of Water Saturated Dense Sand 

      Dahl, Birgitte Misund; Løyland, Marit Skaug (Master thesis, 2017)
      Several monotonic and cyclic triaxial tests have been performed at NGI in association with the ongoing strategic project, SP9. The test material is dense saturated sand from the Siri offshore field in the North Sea, and ...
    • Deformation Analysis of Soft Soils - Case Study of South Ring Road of Gdansk 

      Perszon, Pawel (Master thesis, 2018)
      Nowadays, a significant part of geotechnical analyses refers to settlement problem, due to its impact on designed constructions. The problem is more noticeable when displacements are large, what usually takes places when ...
    • Deformation properties of hard rock TBM-spoil 

      Syversen, Isolde Louise Grønlund (Master thesis, 2021)
      Bruken av tunnelborremaskiner (TBM) i Norge startet på tidlig 1970-tallet, hovedsakelig knyttet til vannkraftverk. I ettertid har det blitt gravd ut over 250 tunneler i Norge med TBM, store deler knyttet til satsningen på ...
    • Development and Evaluation of an Effective Stress Based Model for Soft Clays 

      Bjerre, Jesper (Master thesis, 2015)
      The term, natural soft clay, is commonly used to describe a normal or slightly overconsolidated clay. This soil type may be encountered in e.g. Scandinavia, Eastern Canada and South East Asia. The mechanical response of ...