GEOSCAN, résultats de la recherche


TitreThe Microvibe, a new multi-component portable seismic vibrator
AuteurBrewer, K; Cartwright, T; Pugin, A
SourceSymposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP) 2013 syposium, abstracts; 2013 p. 1,
Séries alt.Secteur des sciences de la Terre, Contribution externe 20120378
ÉditeurEnvironmental and Engineering Geophysical Society
RéunionSAGEEP 2013; Denver, CO; US; mars 17-21, 2013
Mediaen ligne; numérique
Sujetssismicité; modèles sismiques; méthodes sismiques; levés sismiques, sol; géophysique
ProgrammeAquifer Assessment & support to mapping, Géoscience des eaux souterraines
Diffusé2013 05 28
Résumé(disponible en anglais seulement)
From our own observations and those reported in the literature, relatively large seismic vibrators mounted on trucks are limited in their ability to generate energy above 225 Hz. To improve high frequency energy transfer into the ground, we have developed a 400 Watt, two-component 70 kg vibrator that we have named the "Microvibe." Mounted with 6 off-the-shelf tactile transducers in both the vertical (V) and horizontal transverse (H2) directions, this vibrator can provide various types of linear and non-linear sweeps from 20 Hz up to 800 Hz with a 3900 N theoretical peak force for each component. This is approximately 15% of the energy provided by an IVI buggy-mounted Minvib I. In order to help compensate for the reduced energy levels, we increase the time length of the sweep. Our experiments have shown that shear wave energy is minimal above 300 Hz. In comparison, it is common to obtain P-wave reflections at 800 Hz over every type of soil that has been tested so far. The concept of operating with two components mounted on a single device is innovative, providing new insights into near surface shear wave anisotropy and birefringence. We compare data obtained with both the Minivib I and our Microvibe sources. Besides improved resolution, a significant advantage of using the Microvibe portable source is the considerable reduction of the acquisition costs for near surface, high resolution seismic reflection data.