考虑板间相互作用的圆形隧洞板裂屈曲型岩爆力学分析  

Mechanical analysis of slab buckling rockburst in circular tunnel considering the interaction between rock plates

作　　者：魏新江 陈涛涛[2] 王霄 朱汉华[1] WEI Xin-jiang;CHEN Tao-tao;WANG Xiao;ZHU Han-hua(Department of Civil Engineering,Zhejiang University City College,Hangzhou,Zhejiang 310015,China;College of Civil Engineering and Architecture,Zhejiang University,Hangzhou,Zhejiang 310058,China)

机构地区：[1]浙大城市学院土木工程系,浙江杭州310015 [2]浙江大学建筑工程学院,浙江杭州310058

出　　处：《岩土力学》2020年第11期3680-3686,共7页Rock and Soil Mechanics

摘　　要：板裂屈曲型岩爆是高地应力区常见的岩爆破坏模式。针对已有力学模型忽略劈裂岩板间相互作用等不足,建立考虑岩板间水平应力的圆形隧洞薄板力学模型。采用最小势能原理计算荷载作用下岩板弯曲挠度,将其与发生张拉破坏的极限挠度进行比较,由此得出岩爆破坏深度。选取工程实例计算分析,将新模型计算结果与已有模型进行比较,验证了研究的合理性。研究结果表明:洞周处岩板所受荷载较大,板厚较小,岩板弯曲应变能与纵向荷载做功较为接近,较小的板间作用力即可使岩板发生屈曲破坏;随着岩板与洞壁距离增大,岩板厚度增大,应力减小,弯曲挠度较极限挠度减小较快,达到一定深度后,弯曲挠度小于极限挠度;随着埋深增大,应力增大,各块岩板弯曲挠度增大,破坏岩板数量增加,岩爆破坏深度增大。Slab buckling rockburst is a common rockburst failure mode in high geostress areas.In view of the shortcomings of the existing mechanical models,such as neglecting the interaction between the split rock plates,a thin plate mechanical model of circular tunnel considering the horizontal stress between rock plates is established.The bending deflection of rock plate under load is calculated using the principle of the minimum potential energy,and compared with the ultimate deflection of tensile failure,thus the depth of rockburst failure is yielded.The research rationality is validated through the comparison between the calculation results of the new model and existing models by analyzing an engineering case.The results show that the rock plates around the tunnel are subjected to larger loads and smaller plates thickness.Moreover,the bending strain energy of rock plates is close to the work done by the longitudinal loads,and the buckling failure of the plates can be triggered by small inter-plate forces.With the increase of the distance from the tunnel wall,the thickness of rock plates increases and the stress decreases.The bending deflection of rock plate decreases faster than the ultimate deflection.After reaching a certain depth,the bending deflection becomes less than the ultimate deflection.As the buried depth increases,both the stress and bending deflection of each rock plate experience increase.The number of damaged rock plates also increases as well as the depth of rockburst.

关 键 词：岩爆 板裂屈曲 最小势能原理 极限挠度 破坏深度 

分 类 号：TU451[建筑科学—岩土工程]