【摘要】 爆炸应力波作用下新浇混凝土衬砌的破坏模式及安全振动速度是水电、铁道工程隧洞建设中需要解决的重要问题。根据弹性P波及SV波在介质中的传播规律,讨论了P波及SV波在薄层混凝土衬砌中的传播及近似处理方法,依照莫尔-库仑准则、极限拉应力准则、极限拉应变准则,研究了爆炸应力波作用下新混凝土衬砌的破坏模式及安全振动速度。结果表明,入射应力波及衬砌中的折射波对衬砌的破坏作用最主要,折射波在衬砌内产生的反、折射波将降低衬砌中的应力,具有卸载效果;混凝土衬砌的安全振动速度随着龄期的增大而增大,P波入射时,安全振动速度随着入射角的增大而增大,入射角较大时,胶结面容易发生剪切破坏,较小时,容易发生拉伸破坏,SV波入射时,较小角度下容易发生剪切破坏,较大角度时容易发生拉伸破坏;围岩弹性模量越高,衬砌的安全振动速度越小。更多还原

【Abstract】 The failure model of young concrete lining and its safety vibration velocity under explosive loading are important problems in hydroelectric and railway engineering.According to the characteristics of the propagation of elastic P wave and SV wave,the P wave and SV wave transmitting in folium concrete lining and their approximately research method were analyzed.Based on Mohr-Coulomb strength criterion,limiting tensile stress and limiting tensile strain strength criterion,the failure model and safety vibration velocity of young concrete lining under explosive loading were studied.The results indicate that the incident stress wave and refractive wave in the lining is the most dangerous to the concrete lining.The reflecting wave produced at the lining interface will decrease the stress in the lining and has an uninstall effect.The safety vibration velocity of lining increases with the rise of the concrete age.Under the effect of P wave,the safety vibration velocity increases with the accretion of the angle of incidence,the shear failure is easy to take place at a big angle of incidence,and the tensile failure is easy to take place at a small angle of incidence.Under the effect of SV wave,the shear failure is easy to take place at a small angle,but tensile failure will appear in a big angle.The higher modulus of elasticity of the surrounding rock is,the lower safety vibration velocity of concrete lining is.更多还原