【摘要】 隧道洞口段的震害在隧道地震灾害中占据了主要部分,这是由于隧道进出口是隧道唯一暴露的部分,所处的地质条件差,多为严重风化的堆积体,且覆盖层较薄所导致。隧道洞口震害又以洞口仰坡滑塌最为常见。计算中采用的地震波为加利福尼亚Cape地震波,结合汶川地震中受损的烧火坪隧道和龙洞子隧道建立端墙式和削竹式两种隧道洞口形式的计算模型。通过三维离散单元法对隧道洞口段进行地震动力响应模拟,直观显示隧道洞口段的破坏形态。从破坏形态得出相同材料属性和地震波情况下,端墙式洞门的较削竹式洞门的破坏更为严重。通过与隧道洞口段震害资料比较,验证三维离散单元计算程序数值模拟的可靠性。所得结论对隧道工程抗减震的研究具有重要的指导意义。更多还原

【Abstract】 Due to the tunnel portal is the only part uncovered,locating in weakness of geotechnical circumstance which mainly is deposit from completely weathered rock thinly mantled.The seismic damage placed on entrance takes up major share of the tunnel earthquake hazard,which is regularly seen in collapse of slope.The California Cape earthquake wave was used as seismic wave in the calculation which used side wall tunnel portal and bamboo-truncating tunnel portal as the computation modes,combining the actual Shaohuoping tunnel and Longdongzi tunnel.Through analyzing response of seismic simulation at the entrance of a tunnel by 3DEC discrete element method,this paper intuition strictly demonstrated the pattern of destruction and concluded.It was found the damage of side wall tunnel portal was more serious than the damage of bamboo-truncating tunnel portal in the same material properties and seismic waves.That 3DEC,as a numerical simulation,is effective according to comparing the picture of seismic damage at entrance with the simulation results.All these factors have important implications for aseismic and shock-absorbing technologies of tunnel engineering.更多还原