A comparative study for structural bedrock delineation by using conventional geophysical methods


Published: Jan 1, 2001
Keywords:
Geotechnical research Seismic refraction method Vertical electrical sounding Bedrock Anisotropy Karstification
Τ. Δ. ΠΑΠΑΔΟΠΟΥΛΟΣ
I. A. ΑΛΕΞΟΠΟΥΛΟΣ
Π. Ι. ΚΑΜΠΟΥΡΗΣ
Abstract

In this paper is examined the potential and effectiveness of two conventional geophysical methods in geotechnical research. The seismic refraction method that has been successfully used in the past for subsurface bedrock delineation in foundation projects, failed to indicate clear distinction between flysch and limestone bedrock material in the area under investigation. This failure is due to the macro-anisotropy structure of the limestone that resulted from joints, tectonic processes or/and karstic phenomena and later fillings of the voids with argillaceous material. The geoelectrical method of vertical sounding, on the other hand, although provided a clear distinction for the bedrock characterization, failed to distinguish the overburden cover from the underlain flysch formation. Finally, in this paper it is shown that for a successful application of geophysical work in  geotechnical research, it is required effective design, utilization of modern analysis methods and handling more than geophysical methods.

Article Details
  • Section
  • Geophysics
Downloads
Download data is not yet available.
References
BRUNO, P.P.G. and GODIO, Α. 1997. Environmental risk assessment of a shallow aquifer in "Piana Campana" (Italy): a field comparison
between seismic refraction and reflection methods. European Journal of Environmental and Engineering Geophysics 2, 61-76.
HAGEDOORN, J.G. 1959. The plus-minus method of interpreting seismic refraction sections. Geophys. Prosp., 7, 158-182.
LOUIS, J., PAPADOPOULOS, TD., DRAKATOS, G. & PANTZARTZIS, P. 1995. Conventional and modern seismic investigations for rock quality determination at a dam site - a case study. Geophys. Prosp., Vol. 43, 779-792.
OLSON, M., PRASHAR, Y. and INEL, S. 1997. Seismic refraction and downhole velocity surveys for investigation of the Tinemaha dam Inyo County, California. Proc. of the Symp. on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP), March 23-26, Reno Nevada, Vol. I, 345-354.
PALMER, D. 1981. An introduction to the generalized reciprocal method of seismic refraction interpretation. Geophysics, 46, 1508-1518.
ΠΑΠΑΔΟΠΟΥΛΟΣ, Τ.Δ., ΛΟΥΗΣ, Ι. και ΠΑΝΤΖΑΡΤΖΗΣ, Π. 1992. Γεωφυσικός καθορισμός σύνθετης επιφάνειας ολίσθησης σε Γρανιτογνευσιακή μάζα. Annales Géologiques Des pays Helléniques, Τόμος 35, 401-412.
PAPADOPOULOS, TD. and ALEXOPOULOS, J. 1996. Combined geophysical investigations for site soil characterization of Grevena-Kozani meizoseismal area. Inter. Meeting on Results of the May 13, 1995 earthquake, 24-27 May (an. oâë. 4).
PAPADOPOULOS, TD., STAVRAKAKIS, G.N., ALEXOPOULOS, J., KAMBOURIS, P. and VOULGARIS, N. 1997. Combined geophysical methods for subsurface characterization in the framework of microzoning studies. Proc. of the IAEG Intern. Symp. on Engineering Geology and the Environment, Athens, Greece, 23-27 June, 1419-1424.
PHILLIPS, D., GRIMM, R. and HOESTRA B. 1997. Mapping bedrock topography with seismic refraction at an oil and gas field: A comparison of engineering and petroleum exploration methods at a site in the Wind River Basin of Wyoming. Proc. of the Symp. on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP), March 23-26, Reno Nevada, Vol. I, 373-375.
ROGERS, N.T., SANBERG, S.K., MILLER, P. and POWELL, G. 1997. Mapping a near surface variable geologic regime using an integrated geophysical approach. Proc. of the Symp. on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP), March 23-26, Reno Nevada, Vol. I, 463-472.
SJOGREN, B. 1984. Shallow refraction seismics. Chapman and Hall. London New York, 268.
SJOGREN, B. 2000. A brief study of applications of the generalized reciprocal method and of some limitations of the method. Geophys. Prosp., 48, 1-21.
Most read articles by the same author(s)