Sidewall rockburst characteristics of highly stressed circular tunnel under impact load  

作　　者：Wuxing Wu Fengqiang Gong Zongxian Zhang 

机构地区：[1]School of Civil Engineering,Southeast University,Nanjing,211189,China [2]Oulu Mining School,University of Oulu,Oulu,90570,Finland

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2024年第12期4909-4924,共16页岩石力学与岩土工程学报（英文）

基　　金：supported by the National Natural Science Foundation of China(Grant No.42077244).

摘　　要：This study investigated the sidewall rockburst characteristics of highly stressed circular tunnel subjected to impact loads resulting from rock blasting or other mining-related dynamic disturbances,aiming at exploring the influence of vertical prestress and dynamic load on sidewall rockburst.Using a biaxial Hopkinson pressure bar(BHPB)system,we studied the sidewall rockburst of a circular tunnel by applying various prestresses(horizontal and vertical static stresses)to a sand prefabricated circular hole specimen,followed by impact loads.The real-time process and strain field of the sidewall rockburst around the specimen were tracked by the high-speed camera and digital image correlation(DIC).The tests reveal that the sidewall rockburst process can be summarized as:calm stage,slab buckling and spalling stage,rock slabs ejection stage,and V-shaped notch formation stage.Furthermore,the sidewall rockbursts exhibit typical dynamic tensile failure.The mechanism of sidewall rockburst under the coupled static-impact loads was summarized,i.e.the static prestress determines the initial stress and strain distribution,and the vertical prestress influences the affected range and strain values of the strain concentration zone;the impact load disrupts the original static stress equilibrium,inducing alterations in the stress and strain of the surrounding rock and triggering sidewall rockburst.

关 键 词：ROCKBURST SPALLING Vertical prestress Circular tunnel Impact load Biaxial Hopkinson pressure bar 

分 类 号：TD35[矿业工程—矿井建设]