Understanding the mechanism of progressive debonding of bolts is of great significance for underground safety.In this paper,both laboratory experiment and numerical simulation of the pull-out tests were per-formed.The experimental pull-out test specimens were prepared using cement mortar material,and a relationship between the pull-out strength of the bolt and the uniaxial compressive strength (UCS) of cement mortar material specimen was established.The locations of crack developed in the pull-out pro-cess were identified using the acoustic emission (AE) technique.The pull-out test was reproduced using 2D Particle Flow Code (PFC2D) with calibrated parameters.The experimental results show that the axial displacement of the cement mortar material at the peak load during the test was approximately 5 mm for cement-based grout of all strength.In contrast,the peak load of the bolt increased with the UCS of the confining medium.Under peak load,cracks propagated to less than one half of the anchorage length,indi-cating a lag between crack propagation and axial bolt load transmission.The simulation results show that the dilatation between the bolt and the rock induced cracks and extended the force field along the anchorage direction;and,it was identified as the major contributing factor for the pull-out failure of rock bolt.

Hao Shi;Lei Song;Houquan Zhang;Wenlong Chen;Huasheng Lin;Danqi Li;Guozhu Wang;Huayun Zhao

State Key Laboratory for Geomechanics & Deep Underground Engineering,School of Mechanics & Civil Engineering,China University of Mining and Technology,Xuzhou 221116,China;School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan 232001,China;School of Water,Energy and Environment,Cranfield University,Cranfield MK430AL,UK;Glencore Coal Assets Australia,Mount Thorley,NSW 2330,Australia;WA School of Mines:Minerals,Energy and Chemical Engineering,Curtin University,Kalgoorlie WA6430,Australia

矿业科学技术学报（英文版）

[1]Hao Shi;Lei Song;Houquan Zhang;Wenlong Chen;Huasheng Lin;Danqi Li;Guozhu Wang;Huayun Zhao-.Experimental and numerical studies on progressive debonding of grouted rock bolts)[J].矿业科学技术学报（英文版）,2022(01):63-74

Experimental,numerical,studies,progressive,debonding,grouted,rock,bolts,Understanding,mechanism,great,significance,underground,safety,In,this,paper,both,laboratory,simulation,pull,tests,were,formed,experimental,specimens,prepared,using,mortar,material,relationship,between,strength,uniaxial,compressive,UCS,was,established,locations,developed,cess,identified,acoustic,emission,AE,technique,reproduced,Particle,Flow,Code,PFC2D,calibrated,parameters,results,show,that,displacement,peak,load,during,approximately,all,contrast,increased,confining,medium,cracks,propagated,less,than,one,half,anchorage,length,indi,cating,lag,propagation,transmission,dilatation,induced,extended,force,field,along,direction,major,contributing,failure

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