Micropile
An agile technique that adapts to the complexity of the project and its environment.
Foundations, reinforcements, underpinning – discover the wide range of applications of micropile technology used by Soletanche Bachy.
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Micropiles are bored piles with a diameter of less than 300mm.
Micropiles are generally used for repairs to existing foundations and for reinforcing foundations of existing structures. Micropile driving and/or boring machines are light and compact, allowing work to be carried out within the existing structure.
Micropiles can also be used to carry out new construction work and retaining structures such as micro-Berlin-type wall.
Micropiles can bear both compressive and tensile loads and also be used on steep gradients (> 20° from the vertical).
The micropile is supported by a steel bar, a steel tube or an H beam, which is:
- either sealed to the ground using a cement grout, mortar or using micro-concrete for bored micropiles.
- or in direct contact with the ground for displacement micropiles.
What are the advantages of this technique?
Applicable to foundation works, from transmission of tensile loads to angled boreholes, repairs, reinforcements or even retaining works,
Adapts to site constraints: limited height, work from a platform, near existing structures and structures in use, etc.
Adapts to constraints linked to the nature of the ground: stability, drillability, hardness, granulometry, etc.
Implementation
Bored micropiles
Methods of execution of bored micropiles are based on the use of compact drilling machines which allow continuous drilling in direct and/or reverse circulation with a drilling fluid such as air, water, bentonite mud, polymers or cement grout. In order to optimize production, it is common for the reinforcement to comprise a hollow bar or a tube, “self-bored” using a lost tool, allowing drilling fluid and sealing grout to flow through its centre.
Displacement micropiles
In the case of displacement micropiles, the load-bearing component made of steel, iron or precast concrete may be installed by vibro-driving or driving.
When underpinning the foundations of a building, the loads may be totally or partially transferred by jacking to control the effects of differential movements over time. The vertical deformations of micropiles are greater than those of piles of equivalent bearing capacity.
Soletanche Bachy has developed continuous and rigorous real-time monitoring of the foundation construction process to allow immediate action in the case of changes to the foundation construction conditions.
These decision-making tools assist operators in real time to correct any errors which could lead to a lower quality foundation.
Execution controls and monitoring
Did you know?
Ever more innovative and involved in the geotechnical community, Soletanche Bachy continues to develop proprietary tools and techniques and to participate in French and European standardisation.
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Soletanche Bachy
Soletanche Bachy is a world leader in foundations and soil technologies, operating in 60 countries via a network of 80 subsidiaries and branches. The Group delivers the full range of geotechnical processes and provides innovative, effective solutions as either a lead or specialist contractor for turnkey projects with a geotechnical focus or specialist works.
a subsidiary of
Soletanche Freyssinet
Soletanche Freyssinet