【作者】 姜曦；

【导师】 袁大军；

【作者基本信息】 北京交通大学 ， 岩土工程， 2012， 硕士

【摘要】 本文通过数值模拟等方法,以南京长江隧道为工程背景,建立了地层及隧道结构相互作用的三维模型,模型边界选择自由场边界,分别采用工程场地100a概率2%地震波及100a概率10%地震波作为输入地震波,通过三维时程分析研究了大直径水下盾构隧道在两种地震波激振下应力、速率及位移等动力力学响应,研究了结构变化处地震应力集中问题,分析了地震作用下隧道结构可能产生的问题,总结研究了主要抗震措施的抗震效果。主要得出了以下结论：1、盾构隧道具有良好的抗震性能,较强的地震动会使结构出现拉应力,有产生张拉裂缝的趋势；2、地震会使隧道横向产生较大位移,可能影响震后隧道的正常运营；3、粉细砂土层中修建的盾构隧道,在地震中会由于土层液化产生上浮现象；4、隧道结构变化处应力集中明显,地震中破坏风险极大；5、土层加固可有效隔离地震动,减缓结构应力集中,减震效果良好。研究结论可为类似工程的抗震设计提供参考。更多还原

【Abstract】 In the paper a numerical modeling method with a free-field boundary condition is established to simulate the interaction between the ground and the structure having the Nanjing Yangtze River Tunnel as context. In this model, seismic waves with possibility of2%and10%in100a are considered as the input seismic waves, under which dynamic responses like stress, velocity and displacement of the underwater great diameter shield tunnel are studied with3D transient analysis method. The problems of seismic stress concentration in the change of the structure and the adverse effect on the shield tunnel under seismic action have been studied. The function of the main aseismatic constructions has also been presented in the paper. The main conclusions are as follows:(1) The shield tunnel has a favorite anti seismic performance. Tension stress will appear in the structure under strong earthquake with the trend to crack;(2) Massive seismic-induced displacement of the structure may influence the serviceability of the tunnel;(3) For the shield tunnel in the fine sand ground, the structure will float upward while the earthquake fluidifies the sand ground beneath;(4) The seismic stress concentration in the structure change of the shield tunnel is quite obvious which results the high risk of structure failure;(5) The consolidation of the soil layer is efficient aseismatic construction to abate the seismic tress concentration in the structure for the insulation with the seismic action. The conclusions above may be helpful to the anti-seismic design of other projects alike.更多还原