本文選題：小凈距隧道　切入點：V級圍巖　出處：《西南交通大學(xué)》2015年碩士論文

【摘要】：伴隨社會經(jīng)濟水平的不斷提升,交通等基礎(chǔ)設(shè)施領(lǐng)域的建設(shè)也必將蓬勃開展。交通領(lǐng)域的建設(shè),特別是在山區(qū)丘陵地帶,必然會修建大量的隧道工程。在當(dāng)下隧道工程建設(shè)中主要的建造形式有分離式隧道、連拱隧道和小凈距隧道。在地形地貌、地質(zhì)條件復(fù)雜地區(qū)修建隧道工程,由于各方面條件的限制,大都不得以壓縮兩洞間距離,選擇連拱或小凈距形式修建隧道。小凈距施工安全性較高,造價相對低廉,長期可靠性有保障并且其施工技術(shù)要求不高,這些優(yōu)點使得小凈距隧道受到越來越多的重視,也成為了山區(qū)特殊地質(zhì)及地形條件下隧道工程的主要形式之一,這也促使工程界對小凈距隧道施工特點方面開展了眾多的研究。本文以摩圍山隧道為依托工程,具體針對該隧道Ⅴ級圍巖段地質(zhì)條件較復(fù)雜、淺埋和小凈距的特點,從研究隧道開挖后圍巖的應(yīng)力分布特點、變形特征和隧道掌子面施工間距等出發(fā),研究在V級圍巖條件下小凈距隧道的施工過程中的監(jiān)控重點及圍巖穩(wěn)定性。通過模擬分析發(fā)現(xiàn)：采用CRD法開挖小凈距隧道,在開挖完成上半部分后圍巖在拱腰和拱腳處形成應(yīng)力集中區(qū),在下半部分的開挖過程中應(yīng)力集中區(qū)向拱腳移動且最大值進一步增加。小凈距隧道兩洞在開挖過程中相互影響,尤其是兩洞之間夾巖處受影響最為強烈形成相連的應(yīng)力集中區(qū)域,而對于應(yīng)變而言由于后行洞的施工使得隧道圍巖豎向位移也進一步增加,由于隧道淺埋施工時應(yīng)密切注意避免冒頂。對不同的隧道開挖間距,通過對比分析發(fā)現(xiàn)小凈距隧道的施工間距不能過小,因為過小圍巖的位移和應(yīng)力值都會受到影響,每個施工步的應(yīng)力及位移變化都大幅增加,這對圍巖的穩(wěn)定性非常不利,如果開挖造成的擾動超過圍巖的最大承受能力時,隧道圍巖破壞甚至失穩(wěn)就非常可能發(fā)生；而隨著隧道施工間距的增大,又不能很好的把握施工工期。所以選取合理的小凈距隧道兩洞間的施工間距是極其有必要的,應(yīng)當(dāng)綜合考慮不同掌子面施工間距下的分析成果和項目工期來確定工程的合理施工間距。本文的研究成果,對今后類似的工程實踐具有一定的參考意義。
[Abstract]:With the continuous improvement of social and economic level, the construction of infrastructure such as transportation is bound to flourish.Traffic construction, especially in hilly areas, is bound to build a large number of tunnel projects.In the current tunnel construction, the main construction forms are split tunnel, multi-arch tunnel and small clearance tunnel.Because of the limitation of various conditions, it is not possible to construct the tunnel in the form of double arch or small net distance by reducing the distance between the two holes in the construction of tunnel engineering in the area of topography and geomorphology and complex geological conditions.The small net distance tunnel is paid more and more attention because of its high safety, low cost, long term reliability and low technical requirement.It has also become one of the main forms of tunnel engineering under special geological and topographic conditions in mountainous areas, which has prompted the engineering community to carry out numerous studies on the construction characteristics of small spacing tunnels.In this paper, based on the project of Mowei Mountain Tunnel, aiming at the complex geological conditions, shallow burying and small distance of surrounding rock, the stress distribution of surrounding rock after excavation of the tunnel is studied.Based on the deformation characteristics and construction spacing of tunnel face, this paper studies the monitoring emphasis and the stability of surrounding rock in the construction process of small clear distance tunnel under the condition of V class surrounding rock.Through simulation analysis, it is found that CRD method is used to excavate the small net distance tunnel, and the surrounding rock forms a stress concentration zone at the arched waist and arch foot after the excavation of the upper half of the tunnel.During the excavation of the lower part, the stress concentration area moves to the arch foot and the maximum value increases further.The interaction between the two holes in the small spacing tunnel during the excavation process, especially the stress concentration area where the rock intercalation between the two holes is most strongly affected, is formed.For strain, the vertical displacement of surrounding rock is further increased due to the construction of the rear tunnel, and the roof fall should be avoided when the tunnel is shallowly buried.For the different tunnel excavation spacing, it is found that the construction spacing of the tunnel should not be too small, because the displacement and stress value of the small surrounding rock will be affected, and the stress and displacement changes of each construction step will increase greatly.This is very unfavorable to the stability of surrounding rock. If the disturbance caused by excavation exceeds the maximum bearing capacity of surrounding rock, the failure and even instability of tunnel surrounding rock are likely to occur, and with the increase of tunnel construction spacing,Also can not very good grasp the construction period.Therefore, it is extremely necessary to select reasonable construction spacing between two holes in a small net distance tunnel. The reasonable construction spacing should be determined by considering the analysis results under different face construction spacing and the project duration.The research results of this paper have certain reference significance to similar engineering practice in the future.
【學(xué)位授予單位】：西南交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：U451.2

【參考文獻】

相關(guān)期刊論文 前5條

1 萬明富;隧道圍巖凈距討論與小凈距隧道研究[J];公路;2000年07期

2 吳明生,楊轉(zhuǎn)運;小凈距隧道中央巖柱的力學(xué)特性分析[J];內(nèi)蒙古公路與運輸;2005年02期

3 王景春,殷杰;相鄰隧道中心距的研究[J];石家莊鐵道學(xué)院學(xué)報;1995年02期

4 王艷波;;基于FLAC的隧道三臺階七步開挖力學(xué)行為研究[J];山西交通科技;2012年05期

5 肖明清;小間距淺埋隧道圍巖壓力的探討[J];現(xiàn)代隧道技術(shù);2004年03期

相關(guān)碩士學(xué)位論文 前2條

1 謝卓雄;小凈距隧道近接施工圍巖穩(wěn)定性及結(jié)構(gòu)力學(xué)行為特征研究[D];西南交通大學(xué);2005年

2 王金明;地鐵隧道施工引起的地表沉降及變形研究[D];中南大學(xué);2009年

，

本文編號：1703011