Structural Engineering & Civil Engineering

3G CIVIL – TOGETHER WE THRIVE

3G CIVIL: Engineering Consultancy in Structural and Civil Engineering

3G CIVIL is a technical engineering consultancy specialized in structural works and civil engineering. We provide innovative, tailor-made solutions. Our mission is simple: to assess, advise, design, and deliver your projects with creativity, rigor, and passion. We support you at every stage, from feasibility studies and needs assessment to the production of detailed design drawings. Finally, we ensure that project handover is successfully completed. In this way, each phase becomes an opportunity to innovate and optimize.

Moreover, our added value lies in a team of experienced and passionate professionals who share a common vision of structural engineering, civil engineering, and project management. We also provide dedicated technical assistance to infrastructure asset managers, including detailed inspections and accurate diagnostics to preserve and enhance existing structures. In summary, 3G CIVIL guarantees high-quality results and an outstanding client experience by combining innovation and excellence in every project.

9+

Years of Experience

1000+

Projects

Areas of Expertise

Our Areas of Expertise

PMA & Construction Supervision

Technical Diagnostic Study

Execution Design Study

Our realisations

Drone Inspection of a Major Structure’s Supports

Switzerland – Viaduct on National Axis N01 (Bern – Neuchâtel)

Inspection of over 70 viaduct supports.
Mission carried out in partnership through drone-assisted visual inspection.
Objective: assess the structural condition of the supports and detect potential defects or issues.

Detailed Inspections and Monitoring Programs for Civil Structures

Monitoring, Diagnostics, and Structural Pathology – Meurthe-et-Moselle Department, City of Châlons-en-Champagne, Highways A8, A51, A52, A57

Carrying out detailed inspections of civil structures.
Diagnostics and classification according to the IQOA method.
Development of tailor-made monitoring programs, either periodic or intensified.

Technical Assistance & Dispute Management – Le Patio, Bondy (93)

Detailed technical inspection with detection of critical failures. Proposal and implementation of appropriate remedial measures.
Assistance in coordinating works in the context of post-handover damage and disputes.
Management of emergency interventions and support to the property manager in communications with stakeholders (owner, insurers, contractors).

PMA & Construction Supervision

Nuclear Decommissioning: Deconstruction works of asbestos-cement shafts / Repair of civil structures (Cergy) / Expert report on the construction of the Maurecourt footbridge

Calculation Notes and Modeling

Soil Freezing (Framing structure under RER C) / Hydraulic Design Note – Lycée Georges Brassens (Évry) / Verification Note for the Slab of Courbevoie Barracks Parking (La Défense) …

Design and Execution Study / Nuclear Decommissioning

Safety Note, Radiation Protection Management Note, Waste Management Note, Risk Analysis Note, Scenario Note, Existing Structures Justification Note, Design Note, …

Execution Study of Retaining Walls

Waste Disposal Site (Plessis-Bouchard) / Tram Station (Val de Fontenay) / Shopping Center (Mont-Saint-Martin) / Agro-Quarter Montjean (Rungis) / Retaining Walls on the Paris-Versailles Line (Puteaux) …

Strengthening Study

Reinforcement of masonry pillars supporting the Line 6 viaduct (Paris) / RSO and Ground Consolidation of a Building (Paris) / RSO of 4 Parking Structures (Paris) / Structural Retrofitting of the Léonard de Vinci Complex (Montigny-lès-Cormeilles) …

Execution Study

Foundations of the Nelson Mandela Ramp (Charenton-le-Pont) / Supports of the Miroirs Footbridge (Évry) / Supports of the Fouille Loury Footbridge (Saintry-sur-Seine) / Pile Caps and Massifs for Silos (Corbeil-Essonnes) / Jack-Up, Sliding, and Repair of a Footbridge (Massy) …

Other Projects – Construction and Rehabilitation:

Design and sizing of the 5,000 m² AWAC Hangar at Avord (metal structure, foundation blocks, roof, cladding).
Design and sizing of the steel structure elevation of the DGAC Building – Nantes St Brévin Airport.
Execution studies for the creation of a reinforced concrete staircase and openings (7 m on partitions + 2.50 m on the façade) – Rue Bonaparte / Place du Québec 75006 Paris.
Execution studies for the 2-floor elevation – 10 Rue d’Enghien 75010 Paris (framework, composite floors, foundations).
Major rehabilitation – 16 Rue Lalo 75016 Paris (underpinning works, creation of parking, car lift, external elevator).
Reinforcement of reinforced concrete beams and execution studies – École ND des Oiseaux 75016 Paris.
Design and sizing of a tiered roof (5 kN/m²) – Roman Amphitheater, Vosges.
Design and sizing of new reinforced concrete floors and restoration of wall panels – Manufacture de Dijonval, Sedan.
Removal of stability piers and creation of an intermediate floor – Conversion of an industrial hall into a car garage, Pantin.
Diagnostics and reinforcement of floors and foundations – General Inspection of Services, Rue Cambacérès 75008 Paris.
Openings in load-bearing walls with reinforcements (HEB beams, plates, anchors).
Underpinning works beneath façades and partitions, execution phasing.
Industrial slabs: verification of concentrated loads, foundations, and joints.
New reinforced concrete staircases and reinforcement of existing staircases.
Retaining walls (reinforced concrete, gabions) and earth pressure calculations.

Other Projects – Infrastructure and Civil Structures:

Design and sizing of pyrotechnic structures (munition depots, missile hangars, support blocks) on air bases.
Technical control of plans and calculation notes – Pyrotechnic and conventional buildings.
Missile packaging building – Resistance to internal/external explosions (Île Longue, Brest).
Missile storage building – Explosion resistance + 10 m gabion retaining wall (Guenvenez Peninsula, Brest).
Blast and shrapnel protection wall – Prefabricated reinforced concrete elements connected.
Hazard studies – Kerosene leaks on aircraft/refueling trucks, determination of danger zones.
Verification of a boiler room’s resistance to a natural gas explosion.
Verification of metro vaults under construction/crane loads.
Verification of masonry bridges under exceptional convoys (RER lines A and B).
Structural diagnostics of metal staircases – Elevated stations Line 6 metro (replacements).
Verification of Rueil viaduct decks stability, design of anti-derailment device, repair recommendations.
Verification of reinforced concrete, masonry, mixed, and prestressed structures – RER Line B under railway crane passage.
Verification of Galliéni station slab under concentrated loads.
Analysis of cracking in vertical trench walls – Rue Haxo 75020 (thermal gradient).
Technical control of plans and calculation notes – RER / Line 1 Porte Maillot station connection.
Inspection and verification of arch footbridge – Massy Palaiseau (reinforced concrete tie rods), decision to close to the public.