Browsing Norwegian Geotechnical Institute (NGI) Digital Archive by Author "Sivasithamparam, Nallathamby"
Now showing items 1-12 of 12
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3D FE tool for time dependent settlement predictions
Jostad, Hans Petter; Sivasithamparam, Nallathamby; Woldeselassie, B.H.; Lacasse, Suzanne (Chapter, 2016)A newly developed calculation tool for fully coupled general 3D finite element consolidation analyses is presented. The development has been part of an ongoing Research and Development project called GeoFuture and the tool ... -
A Constitutive Model for Soft Clays Incorporating Elastic and Plastic Cross-Anisotropy
Castro, Jorge; Sivasithamparam, Nallathamby (Peer reviewed; Journal article, 2017)Natural clays exhibit a significant degree of anisotropy in their fabric, which initially is derived from the shape of the clay platelets, deposition process and one-dimensional consolidation. Various authors have proposed ... -
A Framework for Versatile Shape of Yield Surfaces for Structured Aniso-tropic Soft Soils
Sivasithamparam, Nallathamby; Castro, Jorge (Chapter, 2016)A framework based on logarithmic contractancy is proposed to produce versatile shapes of yield surfaces for structured anisotropic clays. The recently proposed constitutive model (E-SCLAY1S) is an extension of existing ... -
An anisotropic elastoplastic model for soft clays based on logarithmic contractancy
Sivasithamparam, Nallathamby; Castro, Jorge (Journal article, 2015)A new constitutive model for soft structured clays is developed based on an existing model called S-CLAY1S, which is a Cam clay type model that accounts for anisotropy and destructuration. The new model (E-SCLAY1S) uses ... -
Back-Calculation of Element Tests with a Rate Dependent Soft Soil Model
Yannie, Jorge; Sivasithamparam, Nallathamby (Chapter, 2016)It is well known that soft clays are geo-materials with properties such as fabric, bonding and rate-dependency. The response observed when modelling complex boundary value problems will depend on the ability of the soil ... -
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. (Peer reviewed; Journal article, 2017) -
Discussion: Undrained cylindrical cavity expansion in anisotropic critical state soils
Chen, Shengli; Liu, Kai; Castro, Jorge; Sivasithamparam, Nallathamby (Journal article; Peer reviewed, 2018) -
Evaluation of soil models for improved design of offshore wind turbine foundations in dense sand
Jostad, Hans Petter; Dahl, Birgitte Misund; Page, Ana M.; Sivasithamparam, Nallathamby; Sturm, Hendrik (Peer reviewed; Journal article, 2020)In order to perform optimised and safe design of foundations for offshore wind turbines (OWT), it is important to have calculation tools that describe the key features of water-saturated soil subjected to complex and ... -
Modelling creep behaviour of anisotropic soft soils
Sivasithamparam, Nallathamby; Karstunen, Minna; Bonnier, Paul (Journal article, 2015)This paper presents a three dimensional constitutive model that describes the creep behaviour of natural clays with anisotropic stress–strain response, focussing on robust model implementation. Creep is formulated using ... -
On the stress update algorithm of an advanced critical state elasto-plastic model and the effect of yield function equation
Rezania, Mohammad; Sivasithamparam, Nallathamby; Nezhad, Mohaddeseh Mousavi (Journal article, 2014)This paper investigates the computational performance of S-CLAY1S constitutive model by varying its yield function equation. S-CLAY1S is an advanced anisotropic elasto-plastic model that has been developed based on the ... -
Permissible range of model parameters for natural fine-grained materials
Gras, Jean-Philippe; Sivasithamparam, Nallathamby; Karstunen, Minna; Dijkstra, Jelke (Peer reviewed; Journal article, 2017)This paper presents a three-dimensional constitutive model for natural clay that includes creep, anisotropy and structure, as well as a theoretical means to estimate the range for anisotropy- and structure-related parameters, ... -
Stone column settlement performance in structured anisotropic clays: the influence of creep
Sexton, Brian; Mc Cabe, Bryan A.; Karstunen, Minna; Sivasithamparam, Nallathamby (Journal article, 2016)The recently developed elasto-viscoplastic Creep-SCLAY1S model has been used in conjunction with PLAXIS 2D to investigate the effectiveness of vibro-replacement in a creep-prone clay. The Creep-SCLAY1S model accounts for ...