【作者】 王维嘉；

【导师】 王明年；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2012， 硕士

【摘要】 通过对5.12汶川大地震震害调查,发现震区隧道洞口段破坏情况较普通段严重,认为隧道洞口段为震害设防的重要区段。本文对公路隧道洞口段震害机理进行研究,针对隧道洞口段地震响应的特点,机理分三个方面分析,即洞口段纵向、横向和围岩破坏机理。并在机理研究的基础上提出了洞口段的抗减震措施。其中洞口段纵向震害机理具体研究了洞口段正应力、切应力和位移沿纵向分布的规律,分析了洞口浅埋和洞口软硬岩交界对地震时隧道衬砌的影响；洞口段横向机理研究了隧道横断面上正应力、切应力和位移的分布规律,并与以往经验和规范计算方法进行了对比,提出了改进和修正的建议。还研究了地震时洞口段围岩的破坏机理,分析了从隧道洞口往洞内延伸和穿越软硬岩交界面时围岩内部最大切应力的分布规律,从围岩的角度分析了地震对隧道的影响。然后,研究了具有针对性的隧道洞口段抗减震措施,即：研究了针对洞口段拱部不同部位软弱围岩局部注浆的抗震效果,认为对软弱围岩注浆能够减小地震时软弱围岩附近衬砌的局部应力集中；研究施做不同间距减震缝下洞口段减震效果,分析出减震缝间距与减震效果间关系,提出最优减震效果间距；研究了施做不同厚度减震层下隧道洞口段减震效果,提出最优减震层厚度。更多还原

【Abstract】 According to the5.12Wenchuan earthquake damage investigation, and found that the destruction of the tunnel portal in the earthquake zone than ordinary section, so that the tunnel portal is an important section of anti-damping earthquake damage.This parper studied the earthquake damage mechanism of the road tunnel portal. In view of the characteristics of seismic response of tunnel portal, the mechanism is divided into three aspects of analysis, the portal segment longitudinal, transverse and wall rock failure mechanism. And on the basis of the mechanism of the portal with anti-damping measures.The longitudinal seismic damage mechanism of the tunnel portal section researchs the normal stress, shear stress and displacement along the longitudinal distribution, analysis of shallow buried portal and the soft and hard rock junction on earthquake effect on tunnel lining; the transverse seismic damage mechanism of the tunnel portal cross section researchs the normal stress, shear stress and displacement distribution rule, and compared with past experiences and the standard calculation method, put forward improvement and amendment suggestions. Also studied the failure mechanism of surrounding rock during the earthquake, and researched the law of the distribution of the maximum shear stress of the surrounding rock of the extension and through the junction of hard and soft rock from the tunnel portal to the insideThen, studied targeted anti-damping measures of tunnel portal section:a study of the anti-seismic effect that local grouting to portal arch in different position of weak rock, think of grouting soft and weak surrounding rock can reduce the local stress concentration of the lining close to the soft and weak surrouding rock during the earthquake; research the damping effect when adopt different pitch damping joints, analysis of the relationship between them, put forward the optimum damping effect on the pitch; research the damping effect when adopt different damping layer thickness, put forward the optimum damping layer thickness.更多还原