Understanding the influence of tremie embedment on concrete flow mechanisms during deep foundation construction-Paper

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The study uses OpenFOAM computational fluid dynamics to investigate how tremie-pipe embedment affects fresh-concrete flow during bored-pile construction. Concrete is modelled as a non-Newtonian Bingham fluid, and a gravity-driven pressure-differential setup is used to simulate pouring. Four embedment depths—0, 1, 2 and 3 m—are compared in a reinforced pile model.<br /><br />Tremie embedment does not change the overall flow mechanism: concrete spreads from the tremie, moves mainly vertically within the reinforcement cage, and then flows into the cover zone. This pattern is governed by the reinforcement configuration. In all cases, the new concrete penetrates about 0.55 m into the previous charge before being redirected.<br /><br />Embedment does, however, affect how quickly the new charge reaches the cover zone and how long pouring takes. Lower embedment means less previously placed concrete must be displaced, so the incoming charge enters the cover zone sooner and flows faster. Simulated pour times range from 240 to 500 seconds, with maximum outlet velocities from 0.425 to 0.707 m/s. The faster flow at lower embedment is not caused by a greater pressure differential; it results from the smaller volume of concrete that must be displaced.<br /><br />Although reducing embedment can shorten pouring time, it raises the risk that inaccurate concrete-level measurements could leave the tremie insufficiently submerged, allowing concrete to mix with support fluid and potentially compromising quality. The authors therefore recommend maintaining the industry-recommended minimum embedment of 3 m.

Keywords

OpenFOAM

computational fluid dynamics

tremie-pipe embedment

fresh-concrete flow

bored-pile construction

Bingham fluid

reinforced pile model

pressure differential

pouring time

concrete quality