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GUIDED WAVE DETERMINATION METHOD OF SERVICE LOAD IN PARTIALLY GROUTED BOLT |
| HE Wen，WANG Cheng，NING Jianguo，TANG Yonggang |
| (State Key Laboratory of Explosion Science and Technology，Beijing Institute of Technology，Beijing 100081，China) |
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Abstract Longitudinal guided wave is used to inspect the service load in the partially grouted bolt nondestructively. The stress distribution characteristics of free section and anchoring section in the partially grouted bolt under service load was first analyzed and tensile stress keeps constant in the free section of the bolt. Then group velocity of longitudinal guided wave propagating in the free section of the bolt under different tensile stresses was calculated. The results show that the group velocity decreases linearly with the increase of tensile stress within the elastic distortion range. Experiments were conducted to study the reflection of longitudinal guided wave from the upper interface of anchoring section of partially grouted bolt；and it shows that the upper interface reflection wave can be observed clearly when the frequencies of guided wave are 45–75 kHz. The reflection of longitudinal guided wave from the upper interface of partially grouted bolt and the time of guided wave propagating in the free section of the bolt can be used to determine the service load in the partially grouted bolt；and the theoretical and experimental results of service load-propagation time have the same trend.
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Received: 06 January 2009
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LI Botao1, 2, 3, TAN Yuxuan1, LIN Haifei4, 5*, WEI Jianping1, 2, 3, ZHANG Hongtu1, 2, 3, LI Shugang4, 5, WEI Zongyong4, 5, WANG Pei4, LUO Rongwei4, LIU Yanwei1, 2, 3. Mechanical properties and mesoscopic damage evolution of coal under liquid-nitrogen freezing at different initial temperatures[J]. , 2026, 45(6): 1757-1772. |
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