Experimental and numerical evaluation on debonding of fully grouted rockbolt under pull-out loading
Shuisheng Yu1
Wancheng Zhu2
Leilei Niu2
1.Center for Rock Instability and Seismicity Research,Department of Mining Engineering,School of Resource and Civil Engineering,Northeastern University,Shenyang 110819,China;School of Architectural Engineering,Zhongyuan University of Technology,Zhengzhou 450007,China2.Center for Rock Instability and Seismicity Research,Department of Mining Engineering,School of Resource and Civil Engineering,Northeastern University,Shenyang 110819,China
摘要：The axial loading in rockbolts changes due to stress redistribution and rheology in the country rock mass.Such a change may lead to debonding at rockbolt to grout interface or rupture of the rockbolt.In this study,based on laboratory experi-ments,ultrasonic guided wave propagation in fully grouted rockbolt under different pull-out loads was investigated in order to examine the resultant debonding of rockbolt.The signals obtained from the ultrasonic monitoring during the pull-out test were processed using wavelet multi-scale analysis and frequency spectrum analysis,the signal amplitude and the amplitude ratio(Q)of low frequency to high frequency were defined to quantify the debonding of rockbolt.In addition to the labora-tory test,numerical simulation on the effect of the embedment lengths on ultrasonic guided wave propagation in rockbolt was conducted by using a damage-based model,and the debonding between rockbolt and cement mortar was numerically examined.It was confirmed that the ultrasonic guided wave propagation in rockbolt was very sensitive to the debonding because of pull-out load,therefore,the critical bond length could be calculated based on the propagation of guided wave in the grouted rockbolt.In time domain,the signal amplitude in rockbolt increased with pull-out load from 0 to 100 kN until the completely debonding,thus quantifying the debonding under the different pull-out loads.In the frequency domain,as the Q value increased,the debonding length of rockbolt decreased exponentially.The numerical results confirmed that the guided wave propagation in the fully grouted rockbolt was effective in detecting and quantifying the debonding of rockbolt under pull-out load.
机标关键词：evaluationloadingdebondingexperimentalfullygroutednumericalpull-out
论文发表日期：2022-02-28
在线出版日期：2025-08-15（本平台首次上网日期，不代表文献的发表时间）
页数：15( 84-98 )
英文信息