【摘要】：摘要：在我國,許多隧道是軟弱圍巖地段的大斷面淺埋隧道,這類隧道在施工過程中經(jīng)常發(fā)生隧道塌方、冒頂?shù)仁鹿?給隧道建設(shè)帶來很大困擾。預(yù)加固大斷面隧道施工工法能較好的解決隧道圍巖軟弱、掌子面容易失穩(wěn)等問題。隨著斷面的增大,掌子面的穩(wěn)定成為了開挖穩(wěn)定的控制性因素之一。 論文以FLAC3D為數(shù)值模擬手段,主要進(jìn)行了以下幾個(gè)方面的工作： 1.總結(jié)國外大跨隧道超前預(yù)加固的研究經(jīng)驗(yàn),簡要闡述了巖土控制變形分析(ADECO-RS)方法(新意法)的基本理念。 2.通過數(shù)值模擬計(jì)算了II-VI級圍巖條件下大斷面隧道的開挖情況,研究了相應(yīng)各種情況下掌子面的變形、塑性區(qū)分布、破壞特征以及拱頂位移及地層變形情況。并模擬了隧道斷面尺寸、隧道埋深對掌子面穩(wěn)定性的影響。采用棚式支護(hù)、玻璃纖維錨桿的方法和劈裂注漿對掌子面進(jìn)行加固。 3.在軟巖大斷面隧道開挖過程中,如果沒有初期支護(hù)以及對超前核心圍巖進(jìn)行加固,只采用大管棚預(yù)加固時(shí),其梁拱效應(yīng)不明顯,超前核心圍巖的變形仍然較大,掌子面不能保持穩(wěn)定。超前玻璃錨桿及注漿均能顯著提高核心土自身的強(qiáng)度和剛度,大大減小塑性區(qū)的深度。 4.提出適合的超前預(yù)加固方式。運(yùn)用FLAC3D有限差分軟件,模擬經(jīng)超前預(yù)加固后對掌子面變形、隧道收斂、塑性區(qū)分布、地表沉降的影響。在軟弱圍巖等不良地質(zhì)條件下,通過對掌子面前方核心土進(jìn)行預(yù)加固以及掌子面外的預(yù)注漿支護(hù),可以明顯的提高核心土的強(qiáng)度并改善其受力情況,顯著的減少掌子面的變形和縮小塑性區(qū)范圍,減小了隧道的預(yù)收斂,提高了施工過程中工作面的穩(wěn)定性。
[Abstract]:Absrtact: in our country, many tunnels are large section shallow buried tunnels in weak surrounding rock area, such as tunnel collapse and roof fall often occur in the construction process of this kind of tunnel, which brings great trouble to tunnel construction. Pre-reinforcement of large section tunnel construction method can better solve the tunnel surrounding rock weakness, face instability and other problems. With the increase of the section, the stability of the face becomes one of the controlling factors of the stability of excavation. In this paper, FLAC3D is used as a numerical simulation method, the main work is as follows: 1. This paper summarizes the research experience of advanced pre-reinforcement of long-span tunnels abroad, and briefly expounds the basic idea of geotechnical deformation control analysis (ADECO-RS) method (Xinyi method). 2. The excavation of large-section tunnel under the condition of II-VI grade surrounding rock is numerically simulated, and the deformation, plastic zone distribution, failure characteristics, arch displacement and formation deformation of the face are studied. The influence of tunnel section size and tunnel depth on the stability of the face is simulated. The face of the face is strengthened by the method of sheathing support, glass fiber bolt and split grouting. 3. In the excavation process of large section tunnel in soft rock, if there is no initial support and reinforcement of the leading core rock, the beam and arch effect is not obvious and the deformation of the leading core rock is still large when only the large pipe shed is used to pre-reinforce the tunnel. The face of the palm is not stable. The strength and stiffness of the core soil can be significantly improved by advanced glass bolt and grouting, and the depth of plastic zone can be greatly reduced. 4. A suitable way of pre-reinforcement is put forward. In this paper, FLAC3D finite difference software is used to simulate the influence of the pre-reinforcement on the surface deformation, tunnel convergence, plastic zone distribution and surface settlement. Under the bad geological conditions such as soft surrounding rock, by pre-strengthening the core soil in front of the face and pre-grouting support outside the face of the face, the strength of the core soil can be obviously improved and the stress situation of the core soil can be improved. The deformation of the face is reduced and the range of the plastic zone is reduced, the pre-convergence of the tunnel is reduced, and the stability of the working face in the construction process is improved.
【學(xué)位授予單位】：北京交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：U455.49

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 蔣樹屏,黃倫海,胡學(xué)兵;超大斷面公路隧道的設(shè)計(jì)與研究[J];地下空間與工程學(xué)報(bào);2005年01期

2 雷震宇,郭慶海,周順華;大跨度淺埋暗挖隧道拆撐的數(shù)值模擬[J];地下空間與工程學(xué)報(bào);2005年02期

3 董新平;胡新朋;周順華;;軟弱地層管棚作用特性判別和分析[J];地下空間與工程學(xué)報(bào);2006年04期

4 吳恒濱;張學(xué)富;周元輔;劉佳祥;;小凈距大斷面隧道合理凈距研究[J];重慶交通大學(xué)學(xué)報(bào)(自然科學(xué)版);2010年01期

5 吳軍民;管棚注漿法在淺埋破碎地層隧道開挖中的加固機(jī)理及效用研究[J];國外建材科技;2004年02期

6 楊米加,張農(nóng);破裂巖體注漿加固后本構(gòu)模型的研究[J];金屬礦山;1998年05期

7 陳浩;姜景山;姚海波;;崇文門車站過既有線管棚施工及變形分析[J];隧道建設(shè);2006年01期

8 翟進(jìn)營;楊會軍;王莉莉;;新意法隧道設(shè)計(jì)施工概述[J];隧道建設(shè);2008年01期

9 馬永峰;張志豪;曹力橋;吳健;;淺埋大斷面大跨度連拱隧道施工變形現(xiàn)場監(jiān)測試驗(yàn)研究[J];隧道建設(shè);2010年04期

10 李亮;;超大斷面海底隧道硬巖控制爆破設(shè)計(jì)[J];山西建筑;2009年36期

，

本文編號：2319433