seismic tomography - seismic refraction

seismic

seismic

pasi instruments solve the challenges of subsoil inspections

Seismic surveys make use of the propagation of seismic waves in the ground to obtain information about the characteristics of the subsoil in a non-destructive manner. This geophysical methodology, initially aimed almost exclusively at oil exploration, now finds a wide scope in the field of civil engineering and geotechnics: geologists and geophysicists can obtain areal information not only on the stratigraphy of the subsoil, but also on the properties of materials that will be affected by excavations, buildings and infrastructures, as well as locally characterising the territory in terms of seismic and hydrogeological risks.

Find your application

DEPTH AND GEOMETRY OF BEDROCK
QUALITY OF ROCK, VOLUME OF EXCAVATION MATERIAL, SURVEYS IN LANDFILL
ELASTIC PARAMETERS OF SOIL THROUGH VP AND VS MEASUREMENTS
SEISMIC REFRACTION
SEISMIC TOMOGRAPHY
FOUNDATION STUDIES
SURVEYS IN FAULT AND SHEAR ZONES

SEISMIC REFRACTION

This geophysical method is based on the measurement of the arrival times of the seismic waves refracted by the interfaces between soil stratifications, characterised by different propagation speeds. The new frontier of seismic tomography will open great perspective not only for modelling the main geometrical features, but also for giving accurate details about the underground geological characteristics. The energy source is represented by an impact on the surface. The energy radiates from the "shot point", travelling both directly in the uppermost layer (direct arrivals) and travelling deep down and laterally along layers at a higher velocity (refracted arrivals), and then returning to the surface, where it is measured through the spreading of geophones (10Hz frequency). Energising in different positions on the surface it will be possible to deduce information about the geometry of the deep refractor layer, in many cases coinciding with the bedrock.

WHAT YOU NEED

seismic tomography
instrument

P.A.S.I. GEA24 complete with GEA-PC acquisition software + your laptop / tablet / PC

GEA24 is a compact-sized 24-channel seismograph with a 24 bit data acquisition board and USB interface for external PC (not included in the standard supply). Suitable for all applications, GEA-24 is a reliable, affordable solution for all professional uses.

Also available in configuration 2xGEA24 = 48 channels

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accessories

24 vertical 10Hz (Vp) or 4.5Hz geophones (can also be used for the MASW) 
24 horizontal 10Hz (Vs) or 4.5Hz geophones (can also be used for the MASW)    +
2 standard 5 or 10 m seismic spacing cables    +
Trigger extension cable
Radiotrigger    +
Starter geophone or piezoelectric starter 
Sledge hammer 
Isotta seismic energizer    +
Striking plate 
Horizontal wave striking plate
GPS option
Multitrigger box (for 48 ch. system)

software (choise of one)    +

INTERSISM
ZONDST2D – SEISMIC TOMOGRAPHY 
REFLEXW
RAYFRACT – SEISMIC TOMOGRAPHY

do you need more than 24 channels? DISCOVER THE 2xGEA24 SOLUTIONS

FIND OUT MORE    REQUEST A QUOTATION

accessories

48 vertical 10Hz (Vp) or 4.5Hz geophones (can also be used for the MASW)
48 horizontal 10Hz (Vs) or 4.5Hz geophones (can also be used for the MASW)    +
4x 12-channel seismic cables with 5/10m spacing plus 2x seismic lead-in cables
- or - 
2x 24-channel seismic cables with 5/10m spacing    +
Trigger extension cable
Radiotrigger    +
Starter geophone or piezoelectric starter
Isotta seismic energizer    +
Sledge hammer 
Striking plate 
Horizontal wave striking plate
GPS option
Multitrigger box (to synchronize 2xGEA24 units connected to the same laptop/tablet PC) 

software (choise of one)    +

INTERSISM
ZONDST2D – SEISMIC TOMOGRAPHY 
REFLEXW 
RAYFRACT – SEISMIC TOMOGRAPHY