Freeze-Thaw Enhancement of the Drainage and Consolidation of Fine-Grained Dredged Material in Confined Disposal Areas.
Final rept. May 75-Apr 76,
COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER N H
Pagination or Media Count:
Fine-grained dredged material obtained from disposal sites in the Great Lakes region was subjected to controlled freeze-thaw cycling in a special laboratory consolidometer. Volume changes and permeabilities were observed after full consolidation and freeze-thaw cycling for applied pressures in the range of 0.93 to 30.73 kPa. It was observed that as much as 20 percent or more volume reduction results when dredged material with liquid limits in the range of 60 to 90 percent is subjected to one cycle of freezing and thawing. The degree of overconsolidation by freezing and thawing appears to decrease with increasing amounts of coarse materials and with increasing plasticity. The vertical permeability of all materials examined was increased as much as two orders of magnitude, the greatest increase in permeability occurring for the fine-grained materials at the lowest stress levels. The application of the phenomenon of overconsolidation by freezing and thawing to disposal sites is discussed and site management procedures are suggested. The process appears to be particularly adaptable to regions of cold winters where material frost penetrations of more than 1 m can be obtained, but it can be applied to regions of more moderate winters such as in the Great Lakes region by sequentially depositing and freezing dredged material during the winter months. Author
- Soil Mechanics
- Civil Engineering