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Geotechnical missions

FONDASOL has the right skills to operate at all stages of the life of a structure. The different missions within which FONDASOL operates fall within the scope of the G1 to G5 standard geotechnical engineering missions as defined in the NFP 94-500 standard of November 2013.


G1 mission – Preliminary Geotechnical Studies

G1 ES mission – Site survey

Carried out upstream of a preliminary study, schematic design study, or pre-project summary, this makes it possible to define in advance the geological model for the site, together with the recommendations with a view to installing there an as-yet-undefined structure and to carry out an initial identification of a site’s geological risks via a documentary analysis.

G1 PGC mission – General Constructional Principles

Carried out at the preliminary study, outline study, or pre-project summary stage, this makes it possible to define the general constructional principles that may be envisaged for the project. It is based on defining, carrying out, and/or supervising a geotechnical investigation programme.


G2 mission – Geotechnical design study

G2 AVP mission – at the pre-project stage

Carried out at the pre-project stage, this studies the constructional principles and adaptation of the project to the ground that may be envisaged and provides a dimensioned sketch of a standard profile for each geotechnical structure. It is based on defining, carrying out, and/or supervising a geotechnical investigation programme. This allows an initial approach to defining quantities.

GS PRO mission – at the PROJect stage

Carried out at the project stage, this provides un updated synthesis of the site, the execution methods for the geotechnical structures and the associated threshold values, together with the design calculations for optimized sizing of all the geotechnical structures and for all the phases of construction. It makes it possible to address the quantities / times / costs involved in executing these structures. If necessary, additional investigations are carried out.

G2 DCE/ACT mission – at the tender / contract award stage

This consists in establishing the documents needed for going out to tender to contractors for the execution of the geotechnical structures and in assisting the customer in selecting the contractors and in analysing the bids from an engineering standpoint. 


G3 mission – Geotechnical study and monitoring during execution

The contractor is normally responsible for this, which makes it possible to minimize the residual geotechnical risks through the timely implementation of corrective measures to adapt or optimize.

At the Study stage

It involves studying the geotechnical structures in detail: assumptions, definition and sizing, execution methods and conditions. If necessary, additional investigations may be carried out.

At the Monitoring stage

This involves supervising the execution of the geotechnical structures, verifying the data, and participating in drawing up the Works Completion File and maintenance recommendations for the geotechnical structures.


G4 mission – Geotechnical execution supervision

This is normally the responsibility of the project owner or their representative, and makes it possible to verify that the geotechnical execution study and monitoring comply with the project objectives.

At the execution study Supervision stage

This consists in giving advice on the geotechnical execution study, potential adaptations of the geotechnical structures proposed by the contractor, and on the investigations programme and associated threshold values.

At the execution monitoring Supervision stage

This consists in giving advice, following one-off on-site operations, on the geotechnical context, on the observed behaviour of the structure and surrounding elements, and on adapting or optimizing the geotechnical structure.


G5 mission – Geotechnical diagnosis

During a project or during the life of a structure, these one-off missions involve studying one or more geotechnical elements in a diagnostic frame, but with no involvement in other geotechnical elements.

Following on from documentary analysis, this mission may include defining and carrying out a programme of specific investigations.

Investigations Engineering

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