On the Characteristics of the Dynamic Waveform and the Change of Stress Wave Propagation Velocity in Soil Anchors
DOI:
https://doi.org/10.5614/j.eng.technol.sci.2015.47.6.3Abstract
This research used nondestructive testing technology to evaluate the anchorage quality of soil anchors. We first created a soil model in the laboratory and then performed a nondestructive experiment on the soil anchor using the stress wave reflection method. Our study displays variable characteristics of the acceleration response curve of a soil anchor under transient excitation. The fixed end reflection signal was very strong, while the reflected signal from the embedded end was weak. This is mainly caused by attenuation of both the fixed reflection signal and the stress wave. The stress wave velocity characteristics in the soil anchor were between the values of anchorage medium materials and free anchors. The velocity is not only related to the characteristics of the bolt body and anchorage medium, but also to the adhesive strength between the bolt and anchorage medium.Downloads
References
Kang, H.P., Wang, J.H. & Lin, J., Case Studies of Rock Bolting in Coal Mine Roadways, Chinese Journal of Rock Mechanics and Engineering, 29(4), pp. 649-664, 2010.
Wang, B.Q. & Meng, Y.M., Analysis by Model Test on Anchors in Clay, Journal of Earth Sciences and Environment, 31(2), pp. 195-199, 2009.
Duan, J., Yan, Z.X. & Guo, R.J., Analysis of Anchorage Characteristics and Parameter Influence of Soil Imperfect Anchor, Journal of Central South University (Science and Technology), 43(8), pp. 3209-3215, 2012.
Hao, J.B., Meng, Y.M. & Wang, B.Q., Working Property of Soil Anchors under Loads on Ground Surface, Chinese Journal of Geotechnical Engineering, 31(2), pp. 247-249, 2009.
Jeng, F.S. & Huang, T.H., The Holding Mechanism of Under-Reamed Rock Bolts in Soft Rock, International Journal of Rock Mechanics & Mining Sciences, 36, pp. 761-775, 1999.
Kilic, A., Yasar, E. & Atis, C.D., Effect of Bar Shape on the Pull-Out Capacity of Fully Grouted Rockbolts, Tunnelling and Underground Space Technology, 18, pp. 1-6, 2003.
Kilic, A., Yasar, E. & Atis, C.D., Effect of Bar Shape on the Pull-Out Capacity of Fully Grouted Rockbolts, Tunnelling and Underground Space Technology, 17, pp. 335-362, 2000.
Wang, B.Q. & Meng, Y.M., Analysis by Model Test on Anchors in Clay, Journal of Earth Sciences and Environment, 21(1), pp. 126-129, 2002.
Zou, D.H. Cui, Y. & Madenga, V., Effects of Frequency and Grouted Length on the Behavior of Guided Ultrasonic Waves in Rock Bolts, International Journal of Rock Mechanics & Mining Sciences, 40, pp. 813-819, 2007.
Zhang, C.S., Zou, D.H. & Madenga, V., Numerical Simulation of Wave Propagation in Grouted Rock Bolts and the Effects of Mesh Density and Wave Frequency, International Journal of Rock Mechanics & Mining Sciences, 43(4), pp. 634-63, 2006.
Madenga, V., Zou, D.H. & Zhang, C.S., Effects of Curing Time and Frequency on Ultrasonic Wave Velocity in Grouted Rock Bolts, Journal of Applied Geophysics, 59, pp.79-87, 2006.
Chen, J.G. & Zhang, Y.X., Analysis on Characteristics of Dynamic Signal for Bolt Anchorage System, Chinese Journal of Geotechnical Engineering, 30(7), pp. 1051-1057, 2008.
Sun, B., Zeng, S. & Ding, D.X., Research on Transmit Rules of Stress Wave with Low Strain in Dynamic Test Pile and Anchorage Bolt, Rock and Soil Mechanics, 32(4), pp.1143-1148, 2011.
Beard, M.D. & Lowe, M.J.S., Non-Destructive Testing of Using Guided Ultrasonic Waves, International Journal of Rock Mechanics and Mining Sciences, 40, pp. 527-536, 2003.
Cui, Y. & Zou, D.H., Numerical Simulation of Attenuation and Group Velocity of Guided Ultrasonic Wave in Grouted Rock Bolts, Journal of Applied Geophysics, 59, pp. 3337-344, 2006.
Li, Y., Zhang, C.S. & Wang, C., Study on Several Key Issues in Nondestructive Detection of Bolt Bonding Integrality, Chinese Journal of Rock Mechanics Engineering, 27(1), pp. 108-116, 2008.