Sampling affects all soils, including frozen soils and hydrate-bearing sediments. The authors monitor the stiffness evolution of frozen sands subjected to various temperature and stress conditions using an oedometer cell instrumented with P-wave transducers. Experimental results show the stress-dependent stiffness of freshly remolded sands, the dominant stiffening effect of ice, creep after unloading, and the associated exponential decrease in stiffness with time. The characteristic time for stiffness loss during creep is of the order of tens of minutes; therefore it is inevitable that frozen soils experience sampling disturbances attributable to unloading. Slow unloading minimizes stiffness loss; conversely, fast unloading causes a pronounced reduction in stiffness probably attributable to the brittle failure of ice or ice-mineral bonding.
|Journal of Geotechnical and Geoenvironmental Engineering
|Published - Apr 21 2017
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This research was funded by the U.S. DOE project on methane hydrates. Additional support was provided by the KAUST endowment. The authors are grateful to the anonymous reviewers and the editor for their insightful comments.