The Norwegian Geotechnical Institute (NGI) has presented new long term tests, designed to improve calculation of creep and deformation to benefit numerical modelling.
The new technique was presented at a conference in Sweden last week which marked the end of a four year international research project, financed by EU, aimed to exchange knowledge between academia and industry.
According to NGI, geomaterials such as clay, silt, sand, and peat are all subject to creep and deformations over time and this must be taken into consideration when planning, designing and constructing infrastructure.
“These creep deformations take place extremely slowly and over a lengthy time span. This makes it extremely difficult both to run representative laboratory tests and field studies,” said NGI head of numerical modelling Hans Petter Jostad.
“We have been running special long-term tests at NGI’s Schmertmann Research Laboratory to look into time dependent deformation properties of clays. The purpose is to develop methods to quantify and extrapolate deformations measured in the laboratory during a few days to deformations developing over time periods as long as 50 to 100 years.
“We need to develop the right parameters and procedures, enabling us to estimate deformations for very long time spans. We are now developing a new computation tool for assessment of 3D creep deformations over extended time spans.”
Jostad said that the NGI and its project partners have developed a new modelling tool that it hopes will be available for commercial use in 2016 but added that further research is needed to improve the method.
“The researchers are not only looking into improvements in computation models,” he added. ”They also take interest in measures that can be undertaken to reduce creep and settlements all together, since a minimum level of creep and deformations is always first priority for developers and builders.”
Creep of Geomaterials is a four year research project financed through Marie Curie Industry-Academia Pathways and Partnership (IAPP), which is part of EU’s 7th Framework Programme. The project partners include NTNU and NGI, Norway; Chalmers University of Technology, Sweden; Deltares research institute, the Nederland; Shanghai Jiao Tong University, Cold and Arid Regions Environmental and Engineering Research Institute, China; and the University of Strathclyde, UK.