Large diameter bored pile under support fluid

Installation process in accordance with the requirements of standard  NBN EN1536:1999

1.Implantation, set up, installation and centering of the top casing on the centre of the pile – pre-drilling

2.Drilling of first casing segment, subsequently filled with support fluid (bentonite mud or polymer).

3.The boring continues through filling with thixotropic fluid upon reaching the required depth.

A positive head of support fluid above the groundwater table of at least 2 m is required in order to maintain the required counter pressure.

4.Clean-up of the borehole front at the design depth, removal and recycling of the support fluid (bentonite mud is returned to the surface for sedimentation and desanding). Lowering of the reinforcement.

5. Concrete displaces the support fluid. Concreting is usually carried out by the tremie method.

6. As the concrete reaches the top of the hole, the tremie pipe is retrieved and the short temporary casing is being withdrawn.

7. Complete extraction of the temporary casing and control of the final concrete level

• Executed as single pile, contiguous (tangent) or - less often - secant pile wall

• Suitable for high point loads, important horizontal loads and bending moments

• Bearing or embedment in firm strata or hard rock possible

• Obstacle drilling (when other techniques cannot be implemented)

• Important installation depths (up to > 50 m)

• Create piles with a cut-off level beneath the working platform level possible  ("contrebas")

• Infrastructure works, important industrial projects, large buildings.

• Vibration-free

• Pile with soil extraction: removal of spoil from the job site is required

• Provision should be made to handle the thixotropic fluid

• A stable, dry and flat work platform is required.