【作者】 赵刚；

【导师】 赵玉光；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2005， 硕士

【摘要】 我国在高等级公路的建设中,在特殊地质及地形条件受限的地区,为了高速公路线型及展线的需要,同时为了获得良好的技术经济效果,常常选择连拱结构的隧道方案。目前我国已建成相当数量的连拱隧道,但在连拱隧道建设及运营中往往存在一些问题,如施工方法单一、施工力学不甚明确,缺乏较为系统的可借鉴的设计施工理论。 论文以广惠高速公路小金口双连拱隧道工程为背景,以几何相似比C_L=25容重相似比C_γ=1为基础相似比,以围岩类别进行分组,实现在弹性范围内各控制性物理力学参数的全相似性,对围岩特征、物性、原始地应力场、支护结构刚度和支护时机、开挖步骤进行了严格的相似模拟,完成了Ⅱ、Ⅲ类围岩中,中导坑.双侧壁三导坑法、双洞双侧壁导坑法、中导坑-正洞台阶法和中导坑-正洞全断面法施工方法下不同支护参数共18组的施工全过程相似模型试验,得出了Ⅱ、Ⅲ类围岩中各种施工方法的洞室周边径向位移、锚杆轴力、围岩与支护间压力以及二次衬砌的内力。并采用有限元法对小金口双连拱隧道洞身段施工全过程的二维数值模拟分析,完成了Ⅱ、Ⅲ类围岩中,四种开挖方法共5组连拱隧道的施工全过程弹塑性数值模拟分析。最后总结全文,提出了Ⅱ、Ⅲ类围岩中小金口双连拱隧道的合理施工方法及其相应支护结构的受力特点。更多还原

【Abstract】 When constructing senior highways in China, the project of double-arch tunnel is often adopted in special geologic and limited topography districts in order to meet the need of road type and outspreading road, to get better technological and economical purpose. At present considerable amount twin-bore tunnels have been constructed in our country. But there are many problems in the construction and mobilization of the double-arch tunnels such as construction method is single, construction mechanics not defmitude and the theory of design and construction that we can make for reference is scarce.Based on the Xiaojinkou double-arch tunnel engineering of the Guanghui highway, taking geometric similarity ratio Cl=25 and bulk density similarity ratio Cγ=1 as basic similarity ratio and grouping according to class of surrounding rock, so as to achieve complete similarity of various controlled physical and mechanical parameters in the elastic range and strictly simulate the characteristic of surrounding rock, physical property, original earth stress field, stiffness of support structures and support time, excavation process . 18 groups of similar modeling tests of whole construction process are completed for class II and III surrounding rock with such four construction methods as middle-pilot-and -lateral-pilots, double-section-and-lateral-pilots, middle-pilot-and-half-section and middle-pilot-and-full-section. To study the results of every boring method, the results of the tunnel convergence, the inner force of anchor pipe, the stress between the surrounding rock and support and inner force of liner are gained in the difference construction method in class II and III surrounding rock. And adopting FEM to carry out 2D numerical simulation analysis on whole construction of Xiaojinkou double-arch tunnel body section, completing 5 groups of elastic-plastic numerical simulation analysis on whole construction process in class II and III surrounding rock with the four construction methods mentioned above. At last, the thesis draw the conclusion of reasonable construction technology of Xiaojinkou double-arch tunnel in class II and III surrounding rock and the mechanic property of the support.更多还原