Nongrouted Ratio Evaluation of Rock Bolts by Reflection of Guided Ultrasonic Waves
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 139, Issue 2
Abstract
The objective of this study is to develop and apply reflection methods for guided ultrasonic waves used in evaluating the grout condition of rock bolts installed in a rock mass. Three types of rock bolts with different grouting ratios are prepared. First, piezoelectric disk elements are used as the source of guided ultrasonic waves to investigate grouted nonembedded rock bolts. Second, reflection methods with piezo disk elements and hammer impacts are used with rock bolts embedded in concrete columns. Third, a hammer impact with a center punch is applied for investigating rock bolts embedded in a rock mass in the field. The measured guided waves were analyzed using wavelet transforms. The peak magnitudes of the wavelet transform are used for group velocity calculations. Although piezo disk elements are sufficient as sources for nonembedded rock bolts and rock bolts installed in concrete columns, they do not provide sufficient energy in the field. However, a hammer impact with a center punch can generate guided ultrasonic waves with enough energy to evaluate the nongrouted ratio in rock bolts embedded in a rock mass. The group velocities of the guided ultrasonic waves increase with increasing nongrouted ratio. This study demonstrates that the suggested hammer impact method is effective for evaluating the nongrouted ratio of rock bolts in the field.
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Acknowledgments
This work was supported by National Research Foundation of Korea Grant No. 2011-0018110, funded by the Korean government (MEST), and a Korea University grant.
References
Beard, M. D. (2002). “Guided wave inspection of embedded cylindrical structures.” Ph.D. thesis, Univ. of London, London.
Beard, M. D., and Lowe, M. J. S. (2003). “Non-destructive testing of rock bolts using guided ultrasonic waves.” Int. J. Rock Mech. Min. Sci., 40(4), 527–536.
Daubechies, I. (1988). “Orthonormal bases of compactly supported wavelet.” Commun. Pure Appl. Math., 41(7), 909–996.
Deng, Y., Wang, C., Chai, L., and Zhang, Z. (2005). “Determination of Gabor wavelet shaping factor for accurate phase retrieval with wavelet-transform.” Appl. Phys. B, 81(8), 1107–1111.
Goupillaud, P., Grossman, A., and Morlet, J. (1984). “Cycle-octave and related transforms in seismic signal analysis.” Geoexploration, 23(1), 85–102.
Grossmann, A., and Morlet, J. (1984). “Decomposition of hardy functions into square integrable wavelets of constant shape.” SIAM J. Math. Anal., 15(4), 723–736.
Han, S. I., Lee, I. M., Lee, Y. J., and Lee, J. S. (2009). “Evaluation of rock bolt integrity using guided ultrasonic waves.” Geotech. Test. J., 32(1), 31–38.
Inoue, H., Kishimoto, K., and Shibuya, T. (1996). “Experimental wavelet analysis for flexural waves in beams.” Exp. Mech., 36(3), 212–217.
Jang, S. J., Gwak, S. J., and Kim, D. J. (2006). “A study on the problem and improvement plan of rock bolt pull test for railroad tunnel construction.” J. Korean Soc. Railway, 9(1), 89–94.
Jeong, H. J., and Jang, Y. S. (2000). “Fracture source location in thin plates using the wavelet transform of dispersive waves.” IEEE Trans. Ultrason. Ferroelectr. Freq. Control, 47(3), 612–619.
Kim, H. B., Lee, Y. J., Han, S. I., Kim, T. W., Lee, J. S., and Lee, I. M. (2005). “Development of non-destructive evaluation system and techniques for rock bolt.” Proc., Korean Society for Rock Mechanics Conf., Korean Society for Rock Mechanics, Seoul, Korea, 115–126.
Kishimoto, K., Inoue, H., Hamada, M., and Shibuya, T. (1995). “Time-frequency analysis of dispersive waves by means of wavelet transform.” J. Appl. Mech., 62(4), 841–846.
Lee, I. M., Han, S. I., Kim, H. J., Yu, J. D., Min, B. K., and Lee, J. S. (2012). “Evaluation of rock bolt integrity using Fourier and wavelet transforms.” Tunn. Undergr. Sp. Tech., 28(11), 304–314.
Lee, J. S., Min, B. K., Yu, J. D., Lee, I. M., Han, S. I., and Lee, Y. J. (2008). “Applicability of non-destructive evaluation technique for rock bolt integrity using time-frequency analysis.” World Tunnel Congress, International Tunnelling and Underground Space Association, Lausanne, Switzerland, 726–734.
Na, W. B., Kundu, T., and Ehsani, M. R. (2002). “Ultrasonic guided waves for steel bar concrete interface testing.” Mater. Eval., 60(3), 437–444.
Rioul, O., and Vetterli, M. (1991). Wavelet and signal processing, IEEE Spectrum Magazine, New York.
Santamarina, J. C., Klein, K. A., and Fam, M. A. (2001). Soils and waves—Particulate materials behavior, characterization and process monitoring, Wiley, New York.
Thurner, H. F. (1988). “Boltometer-instrument for non-destructive testing of grouted rock bolts.” Proc., 2nd Int. Symposium on Field Measurements in Geomechanics, Balkema, Rotterdam, Netherlands, 135–143.
Wang, L. (2004). “Elastic wave propagation in composites and least-square damage location technique.” M.Sc. thesis, North Carolina State Univ., Raleigh, NC.
Zhang, C. S., Zou, D. H., and Madenga, V. (2006). “Numerical simulation of wave propagation in grouted rock bolts and the effects of mesh density and wave frequency.” Int. J. Rock Mech. Min. Sci., 43(4), 634–639.
Information & Authors
Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 139 • Issue 2 • February 2013
Pages: 298 - 307
Copyright
© 2013 American Society of Civil Engineers.
History
Received: Jun 2, 2009
Accepted: May 11, 2012
Published online: May 14, 2012
Published in print: Feb 1, 2013
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