Effect of the Number and Orientation of Fractures on the P-Wave Velocity Diminution: Application on the Building Stones of the Rabat Area (Morocco)

Abstract

This study is focused on two types of Moroccan rocks, among the most widely used as building stones: the calcarenite of Salé (CS) and the marble of oued Akrech (MA). The two rocks, lithologically different, show a clear contrast of their P-wave velocities (Vp): 3.90 vs 5.10 km/s at dry state and 4.29 vs 5.64 km/s at saturation. The “Artificial fractures” created in the two rock types reveal that their Vp undergo diminutions which the rates vary depending of the number and the plane orientation of the fractures. In the CS, Vp shows an increasing of cumulative diminution (Dc) according to the number of fractures, but with a variable rate of unitary diminution (Du) from one fracture to the other. This defines a linear regression with a low coefficient of determination (Dc = 10.18NbFr + 10.96; r2 = 0.87). The mode of the Vp evolution would be related to the roughness of fractures surface, which itself depends upon the petrographic nature of the calcarenite (friable structure, high porosity and heterogenous composition). The MA manifested an increasing Dc with a fairly constant rate of Du from a fracture to another, giving a regression line with a high coefficient of determination (Dc = 12.17NbFr10.69; r2 = 0.99). This steady diminution of Vp would be related to the granoblastic texture and the monomineral composition of the marble, which engender smoother fracture surfaces. The rates of Vp diminution also depend on the orientation plane of the fractures relative to the direction of wave propagation. The fractures parallel (θ = 0°) amplify slightly the Vp, playing a significant role of “waveguide”. The fractures oriented at 45° lead to a diminution lower than those of fractures oriented at 25° and 90°. The same trend of diminution, but at variable rates, appears on the samples of the two types of stones at dry and saturated state. This can be explained by the compressive nature of P-waves, which obey the physic laws of the transmission of the constraints in the solid mediums.

Share and Cite:

H. Azhari and I. Hassani, "Effect of the Number and Orientation of Fractures on the P-Wave Velocity Diminution: Application on the Building Stones of the Rabat Area (Morocco)," Geomaterials, Vol. 3 No. 3, 2013, pp. 71-81. doi: 10.4236/gm.2013.33010.

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1] K. Sassa and T. Watanabe, “Velocity and Amplitude of P-waves Transmitted through Fractured Zones Composed of Multiple Thin Low-Velocity Layers,” International Journal Rock Mechanics and Mining Sciences & Geomechanics Abstracts, Vol. 32, No. 4, 1995, pp. 313-324. doi:10.1016/0148-9062(95)00008-5
[2] R. P. Young, T. T. Hill, I. R. Bryan and R. Middleton, “Seismic Spectroscopy in Fracture Characterization,” Quarterly Journal of Engineering Geology, Vol. 18, No. 4, 1985, pp. 459-479. doi:10.1144/GSL.QJEG.1985.018.04.16
[3] P. Gaviglio, “Longitudinal Waves Propagation in a Limestone: The Relationship between Velocity and Density,” Rock Mechanics. Rock Engineering, Vol. 22, No. 4, 1989, pp. 299-306. doi:10.1007/BF01262285
[4] M. S. King, N. A. Chaudhryand and A. Shakeel, “Experimental Ultrasonic Velocities and Permeability for Sandstones with Aligned Cracks,” International Journal Rock Mechanics and Mining Sciences, Vol. 32, No. 2, 1995, pp. 155-163. doi:10.1016/0148-9062(94)00033-Y
[5] T. Chrzan, “The Determination of Rock’s Mechanical Properties with the Use of Ultrasounds,” Proceedings of the 6th International Symposium on Mine Planning and Equipment Selection, Rotterdam, 1997, pp. 315-318.
[6] S. Kahraman, “The Effects of Fracture Roughness on P-Wave Velocity,” Engineering Geology, Vol. 63, No. 3-4, 2002, pp. 347-350. doi:10.1016/S0013-7952(01)00089-8
[7] L. M. Del Rio, F. Lopez, F. J. Esteban, J. J. Tejado, M. Mota, I. Gonzàlez, J. L. San Emeterio and A. Ramos, “Ultrasonic Characterization of Granites obtained from Industrial Quarries of Extremadura (Spain),” Ultrasonics,Vol. 44, Suppl., 2006, pp. e1057-e1061. doi:10.1016/j.ultras.2006.05.098
[8] A. Kilic and A. Teymen, “Determination of Mechanical Properties of Rocks Using Simple Methods,” Bulletin of Engineering Geology and the Environment, Vol. 67, No. 2, 2008, pp. 237-244. doi:10.1007/s10064-008-0128-3
[9] P. K. Sharmaand and T. N. Singh, “A Correlation between P-Wave Velocity, Impact Strength Index, Slake Durability Index and Uniaxial Compressive Strength,” Bulletin of Engineering Geology and the Environment, Vol. 67, No. 1, 2008, pp. 17-22. doi:10.1007/s10064-007-0109-y
[10] I. El Amrani El Hassani and H. El Azhari, “Evaluation des Propriétés Physico-mécaniques des Pierres de Cons- truction du Maroc à partir des Vitesses des Ondes P et de la Résistance au Choc,” Bulletin de l’Institut Scientifique, Rabat, Vol. 31, 2009, pp. 41-54.
[11] M. Khandelwal and P. G. Ranjith, “Correlating Index Properties of Rocks with P-Wave Measurements,” Journal of Applied Geophysics, Vol. 71, No. 1, 2010, pp. 1-5. doi:10.1016/j.jappgeo.2010.01.007
[12] K. Kaneko, I. Inoue, K. Sassa and I. Ito, “Monitoring the Stability of Rock Structures by Means of Acoustic Wave Attenuation,” 4th ISRM Congress, Montreux, September 2-8 1979, pp. 287-292.
[13] M. Schoenberg, “Elastic Wave Behavior across Linear Slip Interfaces,” Journal of the Acoustical Society of America, Vol. 68, No. 5, 1980, pp. 1516-1521. doi:10.1121/1.385077
[14] M. Fehler, “Interaction of Seismic Waves with a Viscous Liquid Layer,” Bulletin of Seismological Society of America, Vol. 72, No. 1, 1982, pp. 55-72.
[15] F. K. Boadu and T. L. Long, “Effects of Fractures on Seismic-Wave Velocity and Attenuation,” Bulletin of Seismological Society of America, Vol. 127, No. 1, 1996, pp. 86-110.
[16] S. Kahraman, “A Correlation between P-Wave Velocity, Number of Joints and Schmidt Hammer Rebound Number,” International Journal Rock Mechanics and Mining Sciences, Vol. 38, No. 5, 2001, pp. 729-733. doi:10.1016/S1365-1609(01)00034-X
[17] R. Altindag and A. Guney, “Evaluation of the Relation- ships between P-Wave Velocity (Vp) and Joint Density (J),” 19th International Mining Congress of Turkey, Izmir, 9-12 June 2005, pp. 101-106.
[18] A. Millies-Lacroix, “Carte géotechnique de la Région de Rabat,” Notes et Mémoires, Vol. 238, 1974.
[19] L.Asebriy, C. Bucci, I. El AmraniElHassani, R. Franchi, F. Guerrera, M. Martin, C. Patamia, G. Raffaelli, P. Robles-Martin and D. J. Tejera, “Etude Intégrée de la Dégradation des Monuments Historiques Romains et Islamiques de la Ville de Rabat (Maroc): Proposition de Solutions Durables de Prévention et de Restauration,” Science and Technology for Cultural Heritage, Vol. 16, No. 1-2, 2007, pp. 45-65.
[20] L. Asebriy, T. E. Cherkaoui, C. Bucci, I. El Amrani El Hassani, R. Franchi, F. Guerrera, M. Martin, C. Patami, G. Raffaelli, P. Robles-Martin, D. J. Tejera and F. Alcala, “Deterioration Processes on Archeological Sites of Chellah and Oudayas (World Cultural Heritage, Rabat, Morocco): Restoration Test and Recommendations,” Italian Journal of Geosciences, Vol. 128, No. 1, 2009, pp. 157-171.
[21] H. El Azhari and I. El Amrani El Hassani, “Diagnostic and Monitoring of Building Stones Using P-Wave Velocity: Application to Historic Monuments of Rabat (Morocco),” 4th International Congress on Science and Technology for the Safeguard of Cultural Heritage in the Mediterranean Basin, Cairo, 6-8 December 2009, pp. 487-494.
[22] ASTMA, “Standard Test Method for Laboratory Determination of Pulse Velocities and Ultrasonic Elastic Constants of Rock: D2845-00,” Book of ASTM, 2000.
[23] Y. Guéguen and V. Palciauskas, “Introduction à la Physique des Roches, Herman, Editeurs des Sciences et des Arts,” 1992, 299 p.
[24] R. Perrier, “La Sonorité des Roches, Etude de la Résonance Longitudinale,” Mines et Carrières, Vol. 78, 1996, pp. 67-73.
[25] R. Perrier, “Les Roches Ornementales,” Edition Pro Roc, France, 2004.
[26] L. M. O. Sousa, D. L. M. Suarez, L. Clalleja, D. V. G. Ruiz and R. A. Rodriguez, “Influence of Microfractures and Porosity on the Physico-Mechanical Properties and Weathering of Ornamental Granites,” Engineering Geology, Vol. 77, No. 1-2, 2005, pp.153-168. doi:10.1016/j.enggeo.2004.10.001
[27] A. R. Gregory, “Fluid Saturation Effects on Dynamic Elastic Properties of Sedimentary Rocks,” Geophysics, Vol. 41, No. 5, 1976, pp. 721-895. doi:10.1190/1.1440671
[28] S. Kahraman, “The Correlations between the Saturated and Dry P-Wave Velocity of Rocks,” Ultrasonics, Vol. 46, No. 4, 2007, pp. 341-348. doi:10.1016/j.ultras.2007.05.003
[29] F. K. Boadu, “Fractured Rock Mass Characterization Parameters and Seismic Properties: Analytical Studies,” Journal of Applied Geophysics, Vol. 36, No. 1, 1997, pp. 1-19.
[30] F. K. Boadu, “Predicting the Transport Properties of Fractured Rocks from Seismic Information: Numerical Experiments,” Journal of Applied Geophysics, Vol. 44, No. 2-3, 2000, pp.103-113.

Copyright © 2024 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.