Diaphragm wall barrettes are rectangular cast in-situ concrete foundation elements that can be installed up to great depths (approx. 60 m). Dimensions are related to the dimensions of the diaphragm wall grabs, e.g.widths of 600, 800, 1000, 1200 and 1500 mm; lengths of 2800, 3000 and 3200; other dimensions are possible by joining multiple sections. Very well suited for transferring large concentrated foundation loads (30 MN is feasible) into the subsoil. The excavations are made using a rope operated heavy-duty grab. The stability of the bore hole is maintained by applying bentonite in the excavated hole. To guide the grab and stabilize the toppart of the barrette a guide frame is placed into the soil over the first couple of meters. After cleaning, the rebar cage can be positioned and concrete can be poured. This is domne using a tremie pipe in order to fille the wexcavation from the bottom. During the concrete pouring the tremie pipe is shortened and the bentonite is pumped away. Before curing of the concrete can occur the guiding frame is removed from the top of the pile.
These piles are used for transferring large concentrated loads at larger depths, such as for tall office buildings, silos, bridges and viaducts. They can also be used as a substitute for multiple piles underneath a column base.
Top-down construction is possible by combining bored piles with prefab concrete columns or steel sections.
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Name of project |
Client |
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Den Haag, Foundation Cultural Centre |
Construction consortium Cadanz |
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Bergambacht, Embankment reinforcement Bergambacht-Ammerstol-Schoonhoven |
Waterauthority Schieland - Krimpenerwaard |
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Rotterdam Maasvlakte, Barettes Coal Silos EMO |
Visser & Smit Bouw |
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Rotterdam Maasvlakte, Foundations Site Centrale |
Visser & Smit Bouw |
