Down-hole seismic testing is performed in survey drilled holes, using three-dimensional well geophones and suitable energization systems.
The down-hole method requires the energy source at surface and the sensors within the hole.
The test uses specific geophones assembled to be lowered and fixed in gradually increasing depth against the wall of a conditioned hole; by energizing the soil surface (artificially by explosive, impact mechanism, etc.) and by measuring the arrival times of the first pulse to geophones, it is possible to determine the speed of the lithotypes encountered in drilling and their elastic modulus. Through appropriate processing, one can determinate:
- Stratigraphy reconstruction;
- Soil mechanical properties valuation;
- Stability analysis on slopes
- Assessing the efficacy of consolidation by injections
- Analysis in tunnel
- Studies on masonry structures
- Foundations analysis