单拱四车道公路隧道施工方法及动力响应三维数值分析研究桥梁与隧道工程专业论文.docxVIP

摘要随着大跨隧道及地下工程的迅速发展，研究其合理的开挖方法及 摘要 随着大跨隧道及地下工程的迅速发展，研究其合理的开挖方法及 其在地震动力荷载作用下的反应问题，具有重大的社会经济效应。因 此，本文以龙头山隧道为工程背景，对单拱四车道公路隧道的施工方 法进行了分析，并对地震荷载作用下的衬砌结构动力响应进行系统深 入的研究。具体的研究工作如下： (1)详细介绍了粘性边界和粘弹性边界，给出了粘弹性边界在有 限元软件中的简便实现途径。 (2)对不同围岩条件隧道的施工方法进行数值计算，分析不同开 挖方法下的隧道力学行为和围岩的稳定性，得出V级围岩隧道采用双 侧壁导坑法和CD法占优，ⅡI级围岩隧道采用台阶法较为合理的结论。 并通过实测结果验证数值计算的可信性。 (3)基于粘弹性边界和土．地下结构相互作用有限元分析方法建立 动力分析模型，得出不同围岩条件、不同边界条件、不同地震波和不 同激励方向的位移、应力、支护内力响应时程曲线，分析地震对隧道 围岩和衬砌结构的影响及其破坏形式，得出：当地震激励方向在水平 面内时，拱顶是最不利位置；当激励方向在竖向时，边墙是最不利位 置；粘弹性动力人工边界的弹簧刚度对计算结果精度的影响很大；随 着围岩等级的降低，隧道衬砌结构的应力和位移响应有增大的趋势。 关键词单拱四车道公路隧道，施工方法，粘弹性边界，动力响应 ABSTRACTWth ABSTRACT Wth the rapid development of the large—span tunnels and underground structures，the researches of reasonable construction method and the seismic respouse analysis of such structures are of great social and economic effect．Therefore，in the engineering background of the longtoushan tunnel，this paper makes a thorough and analytical study of the different construction methods and the seismic dynamic response of the four-lane road tunnel．The concrete research iS as follows： Firstly,the viscous boundary and viscous·spring boundary are introduced in detail．and the simple achieved access in fillite element software of them iS also given． Secondly,the construction methods of different grade surrounding rock are simulated．In addition，the tunnel mechanical behavior and stability are studied．It is shown from analysis that the double side drift method and CD method are superior to the others for surrounding rock grade V，and bench method for surrounding rock HI is considered to be the reasonable one．At the same time，it is verified the credibility of the numerical calculation through field test． At last，based on the viscous·spring boundary and the finite element method for soil．structure interaction problems．a three．dimensional analysis model is presented．Furthermore，the author analysis the displacement，stress and supporting internal force dynamics response in the seismic force by different kinds