本文關鍵詞： 隧道 管棚預支護 力學機理 監(jiān)測試驗 掌子面穩(wěn)定性　出處：《重慶大學》2015年碩士論文　論文類型：學位論文

【摘要】：管棚預支護是一種經(jīng)濟實用的隧道輔助工法,在淺埋暗挖隧道的開挖中發(fā)揮了重大作用。管棚預支護技術擁有加固圍巖、提高隧道圍巖等級及抗?jié)B性能、提高隧道掌子面穩(wěn)定性和控制地表沉降等較多優(yōu)點。本文以滬昆客專貴州段背陰坡隧道工程為依托,以隧道開挖過程中管棚內力和變形以及隧道掌子面穩(wěn)定性為研究對象,通過理論分析、現(xiàn)場試驗和數(shù)值模擬等方法,對管棚預支護力學模型、管棚預支護效果及其影響因素進行了較為系統(tǒng)和深入的研究,并對管棚預支護的設計進行了優(yōu)化。主要研究內容和成果如下:①以管棚預支護與圍巖之間的相互作用關系為基礎,建立了基于雙參數(shù)Pasternak彈性地基梁理論的管棚預支護力學模型,提出了基于有限差分法的管棚內力的求解方法。通過對管棚作用荷載的分析,推導出管棚的擾度方程及應力、應變計算公式;建立了基于地基反力方程的隧道掌子面穩(wěn)定性分析方法,并應用該方法推導了管棚預支護下隧道掌子面極限支護力的計算公式。②通過對滬昆專線貴州段背陰坡隧道的現(xiàn)場監(jiān)測試驗,獲得了隧道拱頂沉降、周邊收斂、地表下沉及管棚預支護的應力應變變化規(guī)律。通過數(shù)據(jù)分析,得到了管棚預支護體系在隧道開挖過程中的受力特性和作用機理。③應用有限元軟件MIDAS/GTS NX,建立了背陰坡隧道在管棚預支護情況下的有限元分析模型,對比了有、無管棚預支護隧道掌子面及圍巖塑性區(qū)范圍、管棚內力變化及隧道凈空變形規(guī)律,并將計算結果與監(jiān)測試驗數(shù)據(jù)進行對比,證實了在淺埋偏壓隧道開挖中,管棚預支護能夠很好地抑制地表沉降和拱頂下沉,提高掌子面及圍巖穩(wěn)定性,滿足工程要求。④系統(tǒng)分析了鋼管直徑、環(huán)向凈距、開挖進尺、管棚長度四種管棚預支護效果的影響因素,并通過有限元軟件建立同一參數(shù)不同情況下的數(shù)值模型,計算各工況下掌子面及圍巖塑性分布區(qū),管棚內力,隧道凈空變形等對掌子面穩(wěn)定性有關的計算結果,得到各參數(shù)對管棚預支護效果的影響程度。最后對各參數(shù)進行優(yōu)化,使管棚工法在今后的地下工程中具有更高的經(jīng)濟性和實效性。
[Abstract]:The pipe-shed pre-support is an economical and practical auxiliary engineering method for tunnels, which plays an important role in the excavation of shallow buried tunnels. The technology of pipe-shed pre-support has the advantages of strengthening surrounding rock, improving the grade of tunnel surrounding rock and improving the impermeability of tunnel surrounding rock. To improve the stability of tunnel face and control the surface subsidence, this paper takes the Yuyin slope tunnel project in Guizhou section of Hukunke special college as the basis, takes the inner force and deformation of pipe shed and the stability of tunnel face as the research object during the tunnel excavation. Through theoretical analysis, field test and numerical simulation, the mechanical model of pipe shed pre-support, the effect of pipe shed pre-support and its influencing factors are studied systematically and deeply. The main research contents and results are as follows: 1. Based on the interaction between pipe shed pre-support and surrounding rock, the mechanical model of pipe shed pre-support based on two-parameter Pasternak elastic foundation beam theory is established. A finite difference method is proposed to solve the internal force of the pipe shed. Through the analysis of the action load of the pipe shed, the perturbation equation and the formula of stress and strain are derived. The stability analysis method of tunnel face based on foundation reaction equation is established. By using this method, the calculation formula .2 of the limit support force of tunnel face under pipe shed pre-support is derived. 2. Through the field monitoring test of the backside slope tunnel in Guizhou section of the Shanghai-Kunming special line, the settlement of the tunnel arch roof is obtained, and the circumference converges. The variation of stress and strain of surface subsidence and pipe shed pre-support. In this paper, the mechanical characteristics and action mechanism of pipe shed pre-supporting system during tunnel excavation are obtained. 3. By using finite element software MIDAS/GTS NX, the finite element analysis model of backcover slope tunnel under the condition of pipe shed pre-support is established, and the results are compared. The range of plastic zone of tunnel face and surrounding rock, the variation of inner force in pipe shed and the law of tunnel clearance deformation without pipe shed are compared with the monitoring test data, and it is proved that in the excavation of shallow burying bias pressure tunnel, The pipe shed pre-support can restrain the ground subsidence and arch roof subsidence, improve the stability of the face and surrounding rock, and meet the engineering requirements of .4 systematic analysis of the diameter of steel pipe, circumferential net distance, excavation advance, The influence factors of pipe shed length on the effect of pipe shed pre-support are analyzed, and the numerical model of the same parameter and different conditions is established by finite element software, and the plastic distribution area of the face and surrounding rock of the pipe shed is calculated under each working condition, and the inner force of the pipe shed is calculated. The calculation results related to the stability of the face of the tunnel, such as tunnel clearance deformation, are obtained, and the influence of each parameter on the pre-support effect of the pipe shed is obtained. Finally, the parameters are optimized. The pipe-shed method is more economical and effective in the future underground engineering.
【學位授予單位】：重慶大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：U455.7

【引證文獻】

相關會議論文 前1條

1 劉新榮;鐘祖良;孫輝;陳曉江;;地下空間利用及其發(fā)展方向的探討[A];全國城市地下空間學術交流會論文集[C];2004年

，

本文編號：1501409