Resources for geotechnical investigations

Throughout France, FONDASOL’s engineers supervise closely the work of the 95 sounding teams and the laboratories, then analyse and interpret the mass of geotechnical data collected.

Thanks to the investigation resources available to them, FONDASOL engineers are in a position to handle the most complex investigation programmes. When necessary, they design instruments themselves to be best suited to their missions.

Types of investigations:

Sounding and in situ testing

• Sampling and reconnaissance: coring, destructive, auger, mechanical digger, digging-type sampler
• Mechanical testing: pressuremeter (standard and up to 13 MPa), rock dilatometer, static and dynamic penetrometer, piezocone, phicometer, SPT, scissometer.
• Water testing: Nasberg, Lefranc, USBR, Lugeon, double ring, very low permeability, pumping tests
• Diagraphy: recording drilling parameters, gamma diagraphy, deviation
• Instrumentation: piezometry, inclinometry, soil settlement gauging, fissurometry, extensometry, strain gauges
• Highway testing: gammadensitometer, plate testing, sand height, PDG 1000, Benkelman beam deflection measurements
• Tensile testing on nails, tie-backs, and micropiles

Laboratory testing

• Soil identification: water content, granulometry, sedimentometry, Atterberg limits, shrinkage limits, VBS, CaCO3 content, LA and MDE tests, fragmentability and degradability, CERCHAR hardness, abrasiveness
• Soil behaviour: PROCTOR, IPI IMMEDIATE LOAD-BEARING, and CBR tests, suitability for treatment
• Soil mechanics: oedometer, simple and triaxial compression, straight-line shear, swelling/shrinkage
• Rock mechanics: simple compression, Brazilian test, joint shearing, propagation speed on sample, Franklin test, measuring Poisson coefficient.
• Concretes: Abrams cone, fitness testing, simple compression, tensile strength
• Cement grout: fitness testing, Marsh viscosity, Baroid balance density, compression
• Bituminous materials: granulometry, binder extraction, ring & ball temperature, penetrability, density

Geophysical

• Seismic: parallel seismic, land and water reflection and refraction seismic, surface waves (MASW), seismic tomography, cross-hole, seismic coring
• Electrical: electrical panels, electrical and towed soundings
• LF electromagnetic: EM 31, EM 34
• HF electromagnetic: radar inspection