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The Development of a Multiscale Modeling Framework for Investigating Marine Soft Clays

Periodic Reporting for period 1 - DOMINO (The Development of a Multiscale Modeling Framework for Investigating Marine Soft Clays)

Reporting period: 2018-09-01 to 2020-08-31

The planning and construction on or in soft marine clays has been proven to remain a challenge for geotechnical engineering. These types of clays are often instable, difficult to characterize and reinforce (i.e. ground improvement), and very common in coastal areas all over the world. The presence of marine soft clays is often the reason for landslides, with hazardous consequences. The complexity of these natural material has hindered the understanding of how macroscopic properties (>meters) such as instability, translates to microscopic (The aim of this project was to develop a multiscale framework for investigating marine soft clays. The objectives were to develop an anisotropic aggregation model for clay, to develop a simple model material with well-defined chemical and mechanical properties, and to compare these simplified models with naturally occurring soft marine clays.
The proposed research aimed to use concepts from aggregation theory in combination with simulations of macroscopic material properties such as stiffness, strength and permeability. Experimental methods have consisted of state-of-the-art material characterization techniques such as: hydromechanical testing using advanced Bishop Wesley cells at Chalmers Geotechnical Laboratory, Nuclear Magnetic Resonance Relaxometry at Gothenburg University’s NMR centre, Time-Resolved Small/Wide angle X-ray Scattering at Chalmers Materials Analysis Lab. The project applied a bottom-up approach, where a combination of simple model materials (kaolinite) are used in addition to natural more complex natural sensitive clay in intact and reconstituted state. The results of these experiment, which are under processing at Chalmers will aid the development of multiscale soil constitutive models.  
The work performed in the project has been to develop a model that can be used to describe the formation of clay aggregates through (anisotropic) aggregation.
The anisotropic model has some interesting scalability properties not, to the knowledge of the researcher, previously published.
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