大断面小净距隧道施工力学行为研究

发布时间：2018-05-05 10:18

  本文选题：小净距 + 大断面隧道　； 参考：《湖南大学》2014年硕士论文

【摘要】：为适应日益增长的经济和交通发展需求，同时解决因分离式隧道最小净距要求所限导致展线不灵活、占地面积大、高边坡等众多突出问题，三车道及三车道以上的公路大断面小净距隧道建设日益增多。然而，由于大断面小间距隧道具有低扁平率隧道结构型式的特点，双洞施工相互影响大，设计和施工过程中存在大量关键问题亟需解决。鉴于此，本文开展了大断面小净距隧道力学行为研究，探讨了双向八车道小净距隧道最小净距的合理取值，研究了大断面小净距隧道中间岩柱加固型式，在此基础上，以白山双洞八车道小净距隧道为背景，对白山隧道衬砌型式及中间岩柱加固型式进行了合理的设计。 本文首先分析了大断面小净距隧道的基本特征，并以三车道大断面小净距隧道为例，通过数值分析，对比了隧道围岩稳定性、隧道衬砌内力等方面对三车道小净距隧道和两车道小净距隧道的影响，研究了三车道大断面小净距隧道和两车道小净距隧道的受力区别。 其次，基于现有研究成果，总结了深埋小净距隧道围岩垂直压力和侧向压力的计算公式；给出了浅埋小净距隧道在后行洞未开挖时先行洞的围岩压力计算公式以及浅埋小净距隧道在后行洞开挖之后先行洞和后行洞的围岩压力计算公式；讨论了深埋和浅埋两种情况下隧道净距、覆土厚度等对隧道垂直压力和侧压力的影响规律。 再次，探讨了小净距隧道最小净距的取值判断准则。运用midas数值软件对双洞八车道小净距隧道最小间距进行了优化，得到了Ⅴ级、Ⅳ级、Ⅲ级围岩下双洞八车道小净距隧道最小净距的合理取值。 最后，，根据工程实践，研究了大断面小净距隧道中间岩柱加固方案，重点探讨了注浆和对拉预应力锚杆等两种小净距隧道中间岩柱加固形式，得到了不同围岩条件下小净距隧道中间岩柱的加固方案。在此基础上，以白山双洞八车道小净距隧道为工程实例，对白山隧道衬砌及中间岩柱加固型式进行了设计。
[Abstract]:In order to adapt to the increasing demand of economy and traffic development, and to solve many outstanding problems, such as inflexibility, large area, high slope and so on, due to the minimum net distance requirement of separated tunnel, The construction of 3-lane and 3-lane highway tunnel with large section and small clear distance is increasing day by day. However, due to the large section and small spacing tunnel has the characteristics of low flat rate tunnel structure type, the construction of double holes has a great impact on each other, there are a lot of key problems in the design and construction process need to be solved. In view of this, the mechanical behavior of large section and small clear distance tunnel is studied in this paper, the reasonable value of minimum net distance of two-way eight lane tunnel with small net distance is discussed, and the reinforcement type of middle rock column of large section and small clear distance tunnel is studied. On the background of Baishan double tunnel with eight lanes and small clear distance tunnel, the lining type of Baishan tunnel and the reinforcement type of intermediate rock column are reasonably designed. In this paper, the basic characteristics of large section and small clear distance tunnel are analyzed, and the stability of surrounding rock of the tunnel is compared by numerical analysis, taking the three-lane tunnel with large section and small clear distance as an example. The influence of tunnel lining internal force on three lane small clear distance tunnel and two lane small clear distance tunnel is studied, and the force difference between three lane large section small clear distance tunnel and two lane small clear distance tunnel is studied. Secondly, based on the existing research results, the calculation formulas of vertical pressure and lateral pressure of surrounding rock of deep buried tunnel with small clear distance are summarized. The calculation formula of surrounding rock pressure of shallow tunnel with small clear distance before excavation is given, and the calculation formula of surrounding rock pressure of shallow tunnel with small net distance after excavation is given. The influences of tunnel spacing and overlying soil thickness on the vertical and lateral pressure of the tunnel are discussed in the case of deep and shallow burying. Thirdly, the criterion of judging the minimum net distance of the tunnel with small net distance is discussed. By using midas software, the minimum spacing of two-hole and eight-lane tunnel with small clear distance is optimized, and the reasonable value of minimum net distance of two-hole and eight-lane tunnel with small net distance under the surrounding rock of grade 鈪

本文编号：1847305