209. thermal improvement of offshore foundation response in soft clays

Department: Structural Engineering
Faculty Advisor(s): John S. McCartney

Primary Student
Name: Ismaail Ghaaowd
Email: ighaaowd@ucsd.edu
Phone: 720-236-0231
Grad Year: 2018

Different from coarse-grained soils, there are not a wide range of effective soil improvement techniques available to enhance the behavior of soft clays besides preconsolidation with surcharge loading, electro-osmosis, or installation of vertical drains. These improvement techniques have been shown to work well for clay deposits on land, but may be difficult for offshore scenarios. This study focuses on a novel approach to improve soft clays through in-situ heating to enhance the pullout capacity of offshore piles (suction caissons or torpedo piles) used to support floating structures. Research is needed to understand: - the strategy for heat injection to cause a desired change in temperature in the soil around the foundation while avoiding excessive changes in temperature - the zone of influence of thermal consolidation (i.e., the zone of a reasonable reduction in void ratio) - the time allotted before mechanical loads are applied - the influence of thermal improvement on the pullout capacities of offshore piles for different loading directions Although the time required for heating and thermal consolidation can be estimated using thermo-elastic analyses with heat flow due to conduction, the complexity involved in the coupled process indicates that these analyses need to be validated using experiments. This research approach involves a combination of heat transfer analysis, pore water pressure prediction, radial consolidation analysis, and centrifuge modeling of thermal effects on the pullout capacity of offshore piles.

Industry Application Area(s)
Civil/Structural Engineering

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