Abstract:
Understanding the influence of tremie embedment on concrete flow mechanisms during deep foundation construction
Thomas Mitchell1, Chris Barker2, Chenfeng Li1
1 Swansea University, Faculty of Science and Engineering, Swansea, UK
2 Ove Arup and Partners Ltd, London, UK
Numerical modelling using Computational Fluid Dynamics (CFD) has been proven effective in simulating the rheological behaviour of fresh tremie concrete. This paper reports on a parametric study investigating the extent to which tremie embedment influences concrete flow mechanisms within bored piles. These observed flow mechanisms are discussed in the context of generating defects within the constructed element. The parametric study uses the open-source CFD software OpenFOAM to model fresh concrete as a non-Newtonian Bingham fluid. A pressure differential approach is used in the numerical model to drive concrete flow, capturing the gravity-driven pour process of the tremie method. Increased tremie embedment reduces concrete velocity at the tremie exit, increases the total pour time, and influences the consumption rate of the previous concrete charge into the cover zone. The general concrete flow mechanism observed within the pile is not influenced by tremie embedment; instead, it is determined by the level of reinforcement in the element.
Keywords: tremie concrete, computational fluid dynamics, bored piles, concrete flow mechanisms, tremie embedment