Gustav Grimstad

Discussion of ‘Soil creep effects on ground lateral deformation and pore water pressure under embankments’

Settlement analysis of field cases is normally studied based on parameters interpreted from laboratory samples influenced by varying degrees of sample disturbance. Such disturbance is more pronounced in natural soft clays and could significantly affect the engineering properties of the soil, e.g. the over consolidation ratio (OCR) and compressibility index (Cc). Hence, it is vital to understand the role of sample quality in relation to soil characterisation for long-term settlement analyses. In this work, this is numerically illustrated by use of a simple creep model along with realistic parameter selection. This work takes its starting point on critical discussion of the work presented by Fatahi et al. (2013) and uses the opportunity to further clarify some important aspects of settlement/creep analyses in light of sample quality and parameter interpretation valid for the corresponding constitutive model.

An elastic-viscoplastic model for saturated frozen soils

This is an Accepted Manuscript of an article published by Taylor & Francis in European Journal of Environmental and Civil Engineering on 30 Dec 2016, available online: http://www.tandfonline.com/doi/full/10.1080/19648189.2016.1271361 . Locked until 30 Dec 2017 due to copyright restrictions

Constitutive Model for Long-Term Behavior of Saturated Frozen Soil

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 of soil grains and ice. The model is able to represent the behavior of frozen soils in different temperatures and ice contents with a single set of parameters. It is also able to simulate the transition between frozen and unfrozen states. The so-called overstress methodis applied for simulating the elastic-viscoplastic deformation of the material due to variation of solid phase stress, while an elastic-plastic formulation is applied for the suction induced deformation. In unfrozen state, the model becomes a conventional elasticviscoplasticcritical state model. The model is implemented in PLAXIS and results are compared with the available testdata and reasonable agreement is achieved.

Creep of geomaterials – some finding from the EU project CREEP

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...

Generalized Constitutive Model for Stabilized Quick Clay

An experimentally-based two yield surface constitutive model for cemented quick clay has been developed at NTNU, Norway, to reproduce the mechanical behavior of the stabilized quick clay in the triaxial p’-q stress space. The model takes into account the actual mechanical properties of the stabilized material, such as “attraction”, friction angle and destructuration. A further attempt has been made to extend the formulation into the full stress space, based on the Hardening Soil Model, the SClay Model, the Koiter Rule and two Mapping Rules. A generalized 3D-constitutive model for stabilized quick clay has been formulated. This paper discusses the formulation process and presents the resulting generalized model. Keywords: Constitutive model, Quick clay, Destructuration, Hardening rule, Yield surface