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LDA pile2023-09-14T14:11:09+02:00

Project Description

Soletanche Bachy presents its full range of piles: bored piles.

LDA (Large Diameter Auger) piles, more commonly known as bored piles, are used mainly as part of the foundation works for major structures or retaining structures.

What is a LDA bored pile ?

A pile is defined as a structural element positioned in the soil to transfer loads and limit distortion. There are no limits on its slenderness ratio. Piles may be uniformly straight, threaded, flared and under-ream, or prefabricated.

Piles may be used in isolation or in groups. They can also form a mixed, continuous, secant or tangent piled curtain retaining wall or a composite curtain wall like a Berlin-type wall or similar. Piles are also used as plunge column (or stanchions) for structural incorporation into a building with basement levels.

Columns of this type are installed before any earthworks begin and can take part of the load imposed by the superstructure when it is constructed in parallel with the basement levels. They may be battered where specified in the installation standards.

The main types of pile include:

Bored piles and barrettes differ in terms of their right cross-sectional shape:

Large-diameter bored (LDA, Kelly) piles are the most traditional and common form of piling worldwide. They are capable of supporting very high loads and coping with complex soil conditions. They are used chiefly in the foundations of major structures, but may also be used to provide support within secant pile walls.

  • Piles are circular in cross-section.
  • Square, rectangular, T-profile, L-profile or any other similar configuration are referred to as barrettes. The barrette methodology and its advantages are detailed in the description of the diaphragm wall technique.

What are the advantages of this technique ?

Cost-efficient piles with a higher load-bearing capacity ratio

A range of interchangeable tools is available to cope with different types of terrain

Piles can be constructed on land or from floating platforms

Environmental benefits

  • Low-carbon concrete, thanks to our EXEGY by Soletanche Bachy supply solution.
  • Electrical equipment, with the use of Hydrofraise® and its electric power pack or connected to a battery pack.
  • Designs optimized by our engineering departments, enabling us to offer variants that reduce the quantity of materials used (steel-free diaphragm walls).

LDA pile implementation

The LDA technique requires the use of powerful hydraulic piling rigs which can use interchangeable attachments such as augers, buckets or core barrels.

Features

  • Bored pile diameters commonly range from 600 mm to 3.6 metres, but are constantly increasing, and can in some cases be up to 5 metres.
  • Depths of 100 metres are also becoming relatively commonplace on land suitable for this type of technique.

Procédé de réalisation d'une paroi moulée à l'Hydrofraise
Procédé de réalisation d'une paroi moulée à l'Hydrofraise

Soletanche Bachy’s advantages

The ability to analyse drilling rigs as the basis for optimising design parameters and confirming soil characteristics

The ability to analyse drilling rigs as the basis for optimising design parameters and confirming soil characteristics

The ability to design and manufacture special tools

The ability to design and manufacture special tools

Dedicated construction work quality control software

Dedicated construction work quality control software

A laboratory dedicated to the development of drilling muds and concrete formulations

A laboratory dedicated to the development of drilling muds and concrete formulations

A modern and versatile fleet of more than 180 LDA piling rigs, 50 crane ropes, 280 crawler cranes and cable excavators

A modern and versatile fleet of more than 180 LDA piling rigs, 50 crane ropes, 280 crawler cranes and cable excavators

Execution controls and monitoring

Supervision and data processing software developed in-house

Soletanche Bachy has developed highly sophisticated, high-performance machines with onboard electronics to guarantee reliable construction of piles and barrettes to cope with all aggregate diameters and/or concreting conditions.

– The inspection measures for barrette construction are detailed in the description of the diaphragm wall technique.

– The drilling rigs of the Soletanche Bachy fleet are all fitted with verticality measurement and parameter acquisition systems directly linked to the Z-Lyze® system developed by Soletanche Bachy.

Zetta-Lyze® provides real-time collection and processing of data generated by the acquisition systems embedded in its fleeting machinery.

Did you know?

Soletanche Bachy uses a range of complementary techniques to improve the performance of standard LDA piles.

Under-ream, or “bell”, piles are perfectly suited to providing exceedingly high-bearing capacities in stable cohesive strata. Under-reaming of piles to produce enlarged bases has traditionally been used to enhance end-bearing capacity and provide economical support for structural mega-columns.

The Group manufactures its own top-hinged tools that are operated mechanically during excavation. They can produce piles with shafts up to 2.4m and enlarged bases up to 7.2m (3 times the shaft diameter).

The ultimate capacity and settlement characteristics of an LDA pile can be enhanced by grouting the base or shaft after it has been constructed.

Steel tubes connected to Tubes-À-Manchettes (TAMs) can be incorporated into the reinforcement cages prior to concreting. Cement grout is injected at high pressure through the TAMs and forced into the ground to consolidate the soil’s characteristics. By flushing out each circuit, the operation can be repeated until the grouting acceptance criteria (pressure and volume) are met. Under certain conditions, it is also possible to inject grout from the top of the pile.

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