Abstract
dc:description.abstractCast-in-place foundations are typically constructed using the Tremie Method of concrete emplacement. A pipe and hopper system is used to fill an excavation from the base up with a specialised, highly workable concrete called Tremie Concrete. In this thesis, numerical modelling and experimental analysis are employed to define what conditions encourage the occurrence of defects in cast-in-place foundations. Two numerical methods were chosen to simulate concrete: Computational Fluid Dynamics (CFD) and the Material Point Method (MPM). A new thixotropic model integrating the Papanastasiou-Bingham model with thixotropy equations was developed, enabling the simulation of thixotropic behaviour of Tremie Concrete in the Material Point Method framework. The novel model revealed a decline in concrete workability during simulations of the Slump-flow and L-box tests after a period of rest which the physical version of the test fails to capture. A classification system of flow behaviours which relies on a scale of flow restriction was developed based on CFD simulations of concrete flow in a novel apparatus designed to represent conditions closer to those found in cast-in-place foundations. Additional simulations of the same apparatus in MPM found the effect of thixotropy and the addition of a support fluid represent further restrictions to flow that can lead to defective foundations. In summary, defects within deep foundations associated with the flow behaviour of concrete during the Tremie Method can be predicted based on the level of restriction to flow the concrete will experience.
Degree
thesis:*- Name dc:type.qualificationname
- Doctor of Philosophy (PhD)
- Level dc:type.qualificationlevel
- Doctoral
- Grantor dc:publisher.institution
- University of Cambridge
- Year dc:date.issued
- 2021
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Wilkes, Christopher
- Advisor dc:contributor.advisor
-
- Biscontin, Giovanna
Subjects
dc:subject × 5Rights
dc:rightsIdentifiers
dc:identifier.*- Author Identifier
-
0000-0002-6829-1997
0000-0002-4662-5650 - OAI identifier oai:identifier
- oai:www.repository.cam.ac.uk:1810/329395