Technical gazette, Vol. 21 No. 1, 2014.
Original scientific paper
Seismic quality index (SQi) of rock mass
Mario Gazdek
orcid.org/0000-0001-9204-5350
; Geotehnički fakultet, Hallerova aleja 7, 42000 Varaždin, Croatia
Mario Bačić
orcid.org/0000-0001-7183-6663
; Sveučilište u Zagrebu, Građevinski fakultet, Zavod za geotehniku, Kačićeva 26, 10000 Zagreb, Croatia
Meho Saša Kovačević
; Sveučilište u Zagrebu, Građevinski fakultet, Zavod za geotehniku, Kačićeva 26, 10000 Zagreb, Croatia
Abstract
The existing rock mass classifications are, to a smaller or larger extent, deficient in regards to the specifics of particular locations. No classification, however, uses the velocity of seismic waves as initial parameters in the classification procedure. This paper introduces the term seismic quality index (SQi) as a comparative indicator of the discontinuity state of rock mass which confirms the potential of velocity of longitudinal waves as a classifier, especially for carbonate rock mass in weathering zones. The field of numerical values for SQi is generated from the relationship slowness – seismic impedance – porosity, in a particular cell of the velocity matrix. Changes in the field of seismic quality index SQi cause changes in velocity values in an observed cell and neighbouring cells. The procedure to determine the seismic quality index will be shown on the example of an actual tomographic seismic profile for which discontinuities were previously defined using a standard geological-geophysical evaluation procedure. Use of SQi on the basis of fields of values, will allow to define more precisely zoning and determine the significance of discontinuities in terms of existing classification of carbonate rock mass in karst regions.
Keywords
Refraction Tomography; Rock Mass Discontinuities; Seismic Quality index
Hrčak ID:
116578
URI
Publication date:
21.2.2014.
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