【摘要】：隨著經(jīng)濟建設(shè)的發(fā)展,國家基礎(chǔ)建設(shè)的持續(xù)投入,高速公路建設(shè)已進入新的發(fā)展時期,并結(jié)合國家一帶一路戰(zhàn)略,以西南地區(qū)為樞紐的交通網(wǎng)將逐步構(gòu)成,西南山區(qū)高等級公路修建過程中,隧道以其能保證運營安全、避免破壞生態(tài)環(huán)境和關(guān)鍵位置縮短行車里程等優(yōu)點得到廣泛應(yīng)用。軟弱圍巖隧道大變形問題是威脅隧道安全的重要問題之一,而解決圍巖大變形問題,除了做好支護措施外,確定合理的預(yù)留變形量,讓圍巖釋放適當(dāng)?shù)淖冃魏蛻?yīng)力,以保證二次襯砌的安全儲備,也是一種方法。相對于復(fù)雜的處治圍巖大變形的方式,讓圍巖產(chǎn)生合理的變形量,且在隧道開挖過程中做好預(yù)留變形顯得更為經(jīng)濟合理。本文以大理海東某隧道為工程研究對象,研究了不同埋置深度和不同圍巖級別條件下隧道圍巖變形的時空規(guī)律及其預(yù)留變形量范圍,在以后規(guī)劃實施的施工條件相差不多的工程當(dāng)中希望可以起到一定的幫助和參考作用。(1)通過對軟弱圍巖的定義、分類、地質(zhì)力學(xué)特征進行查閱,結(jié)合魯賓涅特公式和本構(gòu)關(guān)系對軟巖隧道開挖圍巖變形的機理進行了解析,得到隧道開挖圍巖變形的一般規(guī)律。結(jié)合軟巖隧道變形規(guī)律對軟弱圍巖隧道開挖預(yù)留變形量的確定方法和影響因素進行探究。結(jié)合已修建完成的隧道工程分析發(fā)現(xiàn),現(xiàn)有方法針對軟巖大變形隧道進行預(yù)留變形量確定時都存在一定的問題和不足,在此條件下提出本文的方法和思路。(2)通過對該隧道工程基本狀況的了解,在對其圍巖地質(zhì)條件和隧道支護方式詳細掌握的前提下,采用MIDAS/GTS構(gòu)建隧道模型,考慮到圍巖變形存在的特點,對V類圍巖進行模擬研究時采用蠕變模型。Ⅳ類圍巖進行模擬研究時采用彈塑模性型,在不同埋深工況條件下,通過模擬研究分析隧道圍巖開挖造成巖體變形移動的時空規(guī)律,得到隧道圍巖變形模擬數(shù)據(jù),在此基礎(chǔ)上確定隧道預(yù)留變形量的范圍值。(3)根據(jù)現(xiàn)場監(jiān)測數(shù)據(jù),通過對V級圍巖段大量數(shù)據(jù)統(tǒng)計分析,采用數(shù)理統(tǒng)計學(xué)知識確定隧道預(yù)留變形量取值,結(jié)合數(shù)值模擬結(jié)果綜合確定V級圍巖段隧道預(yù)留變形量為30～35cm, Ⅳ級圍巖段預(yù)留變形量為15～20cm,并在V級和Ⅳ級圍巖段隧道開挖過程中進行驗證性應(yīng)用,通過現(xiàn)場監(jiān)測分析發(fā)現(xiàn)預(yù)留量留設(shè)效果較好,隧道圍巖發(fā)生侵限現(xiàn)象大大減少。通過驗證表明數(shù)值模擬結(jié)果具有一定的參考價值。
[Abstract]:With the development of economic construction and the continuous investment of national infrastructure construction, highway construction has entered a new development period, and combined with the national Belt and Road strategy, the traffic network with southwest region as the hub will be gradually constituted. In the process of highway construction in southwest mountainous area, the tunnel has been widely used for its advantages of ensuring the safety of operation, avoiding the destruction of ecological environment and shortening the driving mileage at key locations. The problem of large deformation of soft surrounding rock tunnel is one of the important problems that threaten the safety of tunnel. In order to solve the problem of large deformation of surrounding rock, in addition to supporting measures, the reasonable reserved deformation amount is determined, and the appropriate deformation and stress can be released by surrounding rock. To ensure the safety of secondary lining reserve, is also a method. Compared with the complex treatment of large deformation of surrounding rock, it is more economical and reasonable to make the surrounding rock produce reasonable deformation and make a good reservation of deformation in the course of tunnel excavation. Taking a tunnel in Dali Haidong as an engineering research object, this paper studies the space-time law of surrounding rock deformation and the range of its reserved deformation under different buried depth and different surrounding rock grade. In the future projects with similar construction conditions planned and implemented, we hope to play a certain role in helping and referencing. (1) by referring to the definition, classification, and geomechanical characteristics of weak surrounding rocks, Based on the Rubenet formula and constitutive relation, the deformation mechanism of surrounding rock in soft rock tunnel excavation is analyzed, and the general law of surrounding rock deformation in soft rock tunnel excavation is obtained. Combined with the deformation law of soft rock tunnel, this paper probes into the method of determining the reserved deformation of soft surrounding rock tunnel excavation and the influencing factors. Based on the analysis of the tunnel project that has been built, it is found that the existing methods have some problems and shortcomings in determining the reserved deformation amount of the large deformation tunnel in soft rock. Under this condition, the method and thought of this paper are put forward. (2) based on the understanding of the basic condition of the tunnel project and the detailed understanding of the surrounding rock geological condition and the tunnel supporting mode, the tunnel model is constructed by MIDAS/GTS. Considering the characteristics of surrounding rock deformation, creep model is used in the simulation of V type surrounding rock, and in 鈪，

本文編號：2197198