Measuring instruments | Pasisrl
 

SEISMIC

PASI instruments
solve the inspection challenges
of the subsoil

SEISMIC

PASI instruments
solve the inspection challenges
of the subsoil
Strumenti per indagini sismiche
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.

Which
methodology
do you want
 to apply?

Quale metodologia vuoi applicare?

 

DISCOVER EVERY POSSIBLE METHODOLOGY AND INVESTIGATION

REFRACTION
This geophysical method is based on the measurement of the arrival times of the seismic waves (P waves and S waves) refracted by the interfaces between soil stratifications, characterized by different propagation speeds.

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 TOMOGRAPHY
FOUNDATION STUDIES
SURVEYS IN FAULT AND SHEAR ZONES

REFLECTION
This geophysical survey is based on measuring the “round trip” travel times of the seismic waves transmitted from the surface and reflected towards the surface of geological horizons with different characteristics.

HIGH-RESOLUTION SURVEYS FOR MODELLING BURIED HORIZONS (FLUVIOGLACIAL AREAS)
SURVEYS ON LANDSLIDE BODIES
SURVEYS ON RIVER, LAKE, ESTUARY BEDS
MODELLING OF AQUIFERS IN SEDIMENTARY AREAS
AQUIFER RESEARCH IN FRACTURED ROCK

SURFACE WAVES
MASW is the acronym for Multichannel Analysis of Surface Waves. This indicates that the phenomenon that is analyzed in detail with this technique is the dispersion of surface waves, that is, the fact that different frequencies - characterized by different wavelengths - travel at different speeds.

VERTICAL PROFILE OF VS - DETERMINING VS30
SEISMIC CHARACTERIZATION OF SOILS
SEISMIC RESPONSE
LOCAL SEISMIC MICROZONATION

BOREHOLE SEISMICS
These prospections involve the use of a surface source and a borehole geophone (downhole surveys) or a source and a geophone arranged in two separate holes (crosshole surveys). Through the use of triaxial borehole geophones, both P and S waves are usually detected.

ASTM 7000-08 (DOWNHOLE SURVEYS)
ASTM D4428 (CROSSHOLE SURVEYS)
VS30 IN HOLES
VP AND VS PROFILES IN HOLES
DEFINITION OF PHYSICAL-MECHANICAL PROPERTIES OF TERRAINS

HVSR / NAKAMURA
Due to the new seismic legislation, the measurement of environmental seismic vibrations or seismic noise has gained considerable importance. The analysis of seismic noise measurements can be conducted using three methods: 1) Fourier spectra 2) Spectral ratios 3) H/V spectral ratios. The latter, which provides the most reliable results, is also known as HVSR (Horizontal to Vertical Spectral Ratio) method or Nakamura method.

LOCAL SEISMIC RESPONSE
ESTIMATE VS30 / VSEQ
SEISMIC CHARACTERIZATION OF SOILS
SEISMIC MICROZONATION

CONTINUOUS SEISMIC MONITORING
In order to observe the evolution of geophysical phenomena such as landslides, slope instability, volcanic activity or induced micro-seismicity over time, continuous seismic monitoring can be performed.

LANDSLIDES AND MONITORING OF UNSTABLE ROCK MASSES
MONITORING IN GLACIAL AND PERIGLACIAL ENVIRONMENTS
MONITORING OF INFRASTRUCTURES (ARTIFICIAL BASINS, RIVER BANKS, ETC.)