Re.Mi.seismic investigations
This method, whose name stands for Refraction Microtremor, uses the same array as M.A.S.W., or seismic refraction, namely low frequency geophones, but instead of recording the seismic perturbation induced by energisation, it records micotremors over a time periods ranging from 20 to 30 seconds.
fields of application:
Definition of Vs, eq
Definition of Soil Classification
Modelling and study of Local Seismic Response
Seismic Microzoning
Study of landslides
SPAC seismicinvestigations
This method requires acquisitions obtained from circular arrays and is rarely used as it requires large spaces (the diameter of a circular array cannot be less than 50m).
fields of application:
Definition of Vs, eq
Definition of Soil Classification
Modelling and study of Local Seismic Response
Seismic Microzoning
ESAC seismicinvestigations
Unlike the SPAC method, geophones can be positioned in any 2D arrangement.
fields of application:
Definition of Vs, eq
Definition of Soil Classification
Modelling and study of Local Seismic Response
Seismic Microzoning
HVSR seismicinvestigations
HVRS passive seismic investigations enable the identification of the natural frequencies of resonance of lands. It is used above all in Seismic Zoning studies and for designing anti-seismic buildings. The versatility of this surveying method is also exploited to obtain the resonance frequencies of a building, which is then compared to that of the land. The technique involves obtaining recordings of environmental noise using a digital tromometer, connected to a seismograph.
fields of application:
Seismic Microzoning
Identification of the site’s natural frequency