本文選題：小凈距 + 大斷面隧道��； 參考：《湖南大學(xué)》2014年碩士論文

【摘要】：為適應(yīng)日益增長的經(jīng)濟(jì)和交通發(fā)展需求，同時(shí)解決因分離式隧道最小凈距要求所限導(dǎo)致展線不靈活、占地面積大、高邊坡等眾多突出問題，三車道及三車道以上的公路大斷面小凈距隧道建設(shè)日益增多。然而，由于大斷面小間距隧道具有低扁平率隧道結(jié)構(gòu)型式的特點(diǎn)，雙洞施工相互影響大，設(shè)計(jì)和施工過程中存在大量關(guān)鍵問題亟需解決。鑒于此，本文開展了大斷面小凈距隧道力學(xué)行為研究，探討了雙向八車道小凈距隧道最小凈距的合理取值，研究了大斷面小凈距隧道中間巖柱加固型式，在此基礎(chǔ)上，以白山雙洞八車道小凈距隧道為背景，對白山隧道襯砌型式及中間巖柱加固型式進(jìn)行了合理的設(shè)計(jì)。 本文首先分析了大斷面小凈距隧道的基本特征，并以三車道大斷面小凈距隧道為例，通過數(shù)值分析，對比了隧道圍巖穩(wěn)定性、隧道襯砌內(nèi)力等方面對三車道小凈距隧道和兩車道小凈距隧道的影響，研究了三車道大斷面小凈距隧道和兩車道小凈距隧道的受力區(qū)別。 其次，基于現(xiàn)有研究成果，總結(jié)了深埋小凈距隧道圍巖垂直壓力和側(cè)向壓力的計(jì)算公式；給出了淺埋小凈距隧道在后行洞未開挖時(shí)先行洞的圍巖壓力計(jì)算公式以及淺埋小凈距隧道在后行洞開挖之后先行洞和后行洞的圍巖壓力計(jì)算公式；討論了深埋和淺埋兩種情況下隧道凈距、覆土厚度等對隧道垂直壓力和側(cè)壓力的影響規(guī)律。 再次，探討了小凈距隧道最小凈距的取值判斷準(zhǔn)則。運(yùn)用midas數(shù)值軟件對雙洞八車道小凈距隧道最小間距進(jìn)行了優(yōu)化，得到了Ⅴ級、Ⅳ級、Ⅲ級圍巖下雙洞八車道小凈距隧道最小凈距的合理取值。 最后，，根據(jù)工程實(shí)踐，研究了大斷面小凈距隧道中間巖柱加固方案，重點(diǎn)探討了注漿和對拉預(yù)應(yīng)力錨桿等兩種小凈距隧道中間巖柱加固形式，得到了不同圍巖條件下小凈距隧道中間巖柱的加固方案。在此基礎(chǔ)上，以白山雙洞八車道小凈距隧道為工程實(shí)例，對白山隧道襯砌及中間巖柱加固型式進(jìn)行了設(shè)計(jì)。
[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

本文編號：1847305