Infrastructure and buildings

The works include: refurbishing the existing car parks, creating a new car park with electric vehicle charging stations, replacing the windows and doors, installing a new HVAC (Heating, Ventilation and Air Conditioning) system, including a study to reinforce the floors, replacing the lighting with LEDs and the false ceilings, and replacing the main low voltage electrical distribution panel.
The project management mission includes: the preliminary design phase and the project phase, including the definition of the works, studies and design, the project study phase, the study and execution plans phase, the tender documents phase (consultation file), the construction management phase and the project handover assistance phase. 

The project involves restructuring an office building that was built in 1993. The restructured building will consist mainly of offices (20,000 m²), residential accommodation (939 m²), shops on the ground floor (275 m²), sports facilities and underground parking.
From a structural point of view, in terms of major works, the building will be raised from a three-storey building (GF+2) to a seven-storey building (GF+6).
The project includes a geotechnical investigation (G5) coupled with a geotechnical design study in the preliminary project phase (G2 AVP) in accordance with the NF P 94-500 standard. The lengths of the existing piles were determined using two different methods: parallel seismic (PS) and impedance.

A preliminary study to carry out geotechnical and structural investigations prior to the partial demolition of the Décathlon building in Nanterre-la-Boule (department 92).
The project is part of the construction of the future Nanterre-la-Boule (NLB) station, which is located on the route of the future metro line 15.

• 9 excavations to identify the foundations of the building.
• 15 horizontal core drillings in the concrete walls and the flint stone wall.

Following the discovery of structural defects in a ground floor slab (cracks penetrating the entire surface, opening up to several millimetres) and in the infrastructure walls, an office building with five floors and a basement, which urgently needed to be reinforced, was evacuated. The assessment revealed that the infrastructure walls were undersized, the reinforcement in the area of the column heads was faulty and the foundation soil had been damaged by water from a faulty perimeter drainage system.
The project includes strengthening the foundations with micropiles, reinforcing the columns with carbon, and strengthening the basement walls and slabs with additional reinforcement and shotcrete. Modifications to the perimeter drainage network are also planned.

Diagnostics and recommendations for repair work, with an estimate of the overall budget in the preliminary design phase.

• G2PRO geotechnical design study.
• Project management for the repair work in the preliminary project phase, project study phase, tender documents phase and the contract award phase.
• Project management for repairs during the VISA phase.
• G4 geotechnical supervision of the works.

Geotechnical studies: G1 general construction principles phase, G2 preliminary design phase and G2 project study phase Infiltration study.

• Static and dynamic penetrometer surveys.
• Destructive drilling to a depth of 40m with pressuremeter tests (for use of the stadium by the club).
• Core drilling to a depth of 20m.
• Laboratory tests.
• Foundation surveys using destructive drilling. 

As part of the G2PRO (project study phase) mission for the extension of the Regional Cancer Centre of the Poitiers University Hospital, a karst check was carried out at each of the pile structure supports.

• 137 x 25 m destructive boreholes.
• 4 x pressuremeter tests at a depth of 25 m.

A structural analysis of buildings A, C, D and H as part of a project to renovate the Manufacture des Tabacs,
The project involved carrying out inspections, surveys, measurements and tests in order to provide an opinion on the state of deterioration of the elements studied, the origin of the structural defects observed, any negative effects on the load-bearing capacity and recommendations for repairs.
The types of structures subject to the investigations include: masonry walls and chimneys, vaulted floors (brick or stone masonry), wooden floors, reinforced concrete floors, steel-framed floors, timber framework and columns and cast iron columns.

Civil engineering assessment of water and wastewater structures to determine their state of repair.

• Visual inspection of visible structural defects.
• Structural analysis of the entire structure.
• Recommendations and preliminary cost estimates for possible repairs.
• Detailed visual inspection of interior and exterior damage and structural defects.
• A plan showing the location of all defects and a photographic report.

A major geotechnical investigation campaign, carried out in several operations to a tight schedule, with 4 to 5 drilling units working simultaneously. In a dense urban environment, in car parks, roadways and pavements, sometimes requiring the work to be carried out at night.

• Core drilling, pressure testing, cone penetration testing and standard penetration testing, at depths from 10m to 40m.
• Dynamic penetrometer surveys and excavations using excavators.
• The installation of piezometers and monitoring with automatic water level sensors over a period of one year.
• Laboratory tests on soils: granulometric analysis by sieving and sedimentation, methylene blue value, Atterberg limits, water and organic matter content, odeometer tests, shear tests, and Proctor and California Bearing Ratio tests. Physico-chemical analyses: inert waste storage package and 12 heavy metals, as well as water and soil aggressiveness tests.
• Drafting of summary reports on geotechnical investigations categorised by structure (P+R car park, roads, footbridges, supports, test beds, etc.).
   

Geotechnical investigation mission involving drilling and testing in alluvial zones:

• 6 pressuremeter surveys (40 m deep).
• 6 core samples (40 m deep).
• 5 mechanical digging surveys.
• Laboratory tests.
   

Civil engineering works for the main works contract for the Benoit Malon/Pierre Ronde section of the A57 motorway.
The demolition of existing structures and the reconstruction of double-supported structures, new structures, reinforced concrete walls and acoustic screens.

As part of the independent inspection and technical assistance provided to the project manager, the mission covers the following areas:

• Technical inspection of concrete and its constituents
• Technical inspection of deep foundations and diaphragm walls
• Technical inspection of injections and monitoring of injection grouts
• Technical inspection and acceptance of zero tolerance structures and metal framework.