本文選題：大斷面 + 連拱隧道�。� 參考：《重慶交通大學》2015年碩士論文

【摘要】：隨著我國國民經(jīng)濟的快速發(fā)展,大斷面連拱隧道作為一種新型的結構形式已被廣泛采用。但由于其結構失跨比小,跨度大,隧道結構施工過程受力狀態(tài)遠比一般連拱隧道復雜。中隔墻是連拱隧道結構受力的核心構件,拉、壓、彎、剪、扭均有,同時左右洞施工對中隔墻影響,增加了施工變形和穩(wěn)定的控制,中隔墻的力學行為直接關系到隧道整體結構的穩(wěn)定性。因此,深入分析研究中隔墻力學行為及變形特征和穩(wěn)定性影響因素,對大斷面連拱隧道的設計和施工具有指導意義。本文依托貴陽遵義中路隧道工程為背景,對目前國內外普遍采用的六種中隔墻形式,在支護參數(shù)、中墻寬度、高度、圍巖類別均相同的情況下,運用ANSYS12.0建立四個二維平面有限元模型,分析他們各自受力變形規(guī)律和結構安全系數(shù)。接著對連拱隧道中隔墻的施工過程建立三維空間有限元模型,對連拱隧道開挖時中隔墻的力學行為及變形特性、左右洞的相互影響進行了分析,同時在原有施工步驟上,中墻一側、頂部是否回填對中隔墻穩(wěn)定性進行分析。主要研究成果包括:1收集連拱隧道中隔墻斷面形式,分析各個斷面形式的優(yōu)缺點和適用條件,為連拱隧道中隔墻斷面選擇提供參考。2通過對六種中隔墻形式二維模擬,得出各中隔墻施工結束都處于偏壓狀態(tài),分層直中墻偏壓受力最大,且各中隔墻結構都是安全的,整體曲中墻安全系數(shù)最大,中空直中墻安全系數(shù)最小。3中隔墻在施工過程中一直處于偏壓狀態(tài),其豎向應力呈臺階式收斂,各施工工序對中墻凹處的豎向應力影響變化幅度最大,底部豎向應力影響變化幅度最小,各截面中墻中心測點變化平緩。4采用中導洞—臺階法開挖時,左洞開挖掌子面影響范圍18m,右洞開挖掌子影響范圍24m,提出了軟弱圍巖大斷面連拱隧道中兩洞開挖掌子面合理間距為2B(單洞開挖跨度為15m)。5采用中導洞—臺階法開挖時,左洞施工對中隔墻應力的影響范圍為18m,右洞施工對中隔墻的應力影響范圍為27m。6在原有施工步驟下,采取在中隔墻頂部回填右側回填、中隔墻頂部回填右側不回填和中隔墻頂部不回填右側不回填3種情況模擬分析中隔墻穩(wěn)定性影響因素,得出中隔墻頂部右側均回填有利于中墻穩(wěn)定。
[Abstract]:With the rapid development of China's national economy, large section multi-arch tunnel has been widely used as a new type of structure. However, due to its small span loss ratio and large span, the stress state of tunnel structure is much more complicated than that of common multi-arch tunnel. The middle partition wall is the core component of the structure of the multi-arch tunnel. There are tension, compression, bending, shear and torsion. At the same time, the construction of the left and right tunnels has an effect on the middle partition wall, which increases the construction deformation and stability control. The mechanical behavior of the middle partition wall is directly related to the stability of the whole tunnel structure. Therefore, it is of guiding significance for the design and construction of large-section multi-arch tunnel to deeply analyze the mechanical behavior, deformation characteristics and influence factors of stability of the partition wall. Based on the background of Guiyang Zunyi Middle Road Tunnel Project, this paper introduces six types of middle partition wall which are widely used at home and abroad, under the condition of the same supporting parameters, middle wall width, height and surrounding rock type. Four two-dimensional finite element models are established by using ANSYS12.0, and their stress and deformation laws and structural safety factors are analyzed. Then the three-dimensional finite element model is established for the construction process of the partition wall in the multi-arch tunnel. The mechanical behavior and deformation characteristics of the partition wall during the excavation of the multi-arch tunnel and the interaction between the left and right tunnels are analyzed. At the same time, the original construction steps are also discussed. The stability of the middle wall is analyzed by backfilling on the side of the middle wall and the top of the wall. The main research results include: 1 collect the cross-section form of partition wall in multi-arch tunnel, analyze the advantages and disadvantages and applicable conditions of each section form, and provide reference for the selection of partition wall section in multi-arch tunnel through the two-dimensional simulation of six kinds of middle partition wall form. It is concluded that the construction of each middle partition wall is in a state of bias, and the eccentric force of the layered straight middle wall is the largest, and the structure of each middle partition wall is safe, and the safety factor of the integral curved middle wall is the largest. The minimum safety factor of hollow straight middle wall is 3. 3. The middle partition wall has been in the state of bias during the construction process, and its vertical stress converges step by step, and the influence of each construction procedure on the vertical stress in the middle wall concave is the greatest. The effect of vertical stress on the bottom is the smallest, and the change of measuring point in the center of each section of the wall is gentle. 4. When excavating with the method of mid-guide cavern and step method, The influence range of left hole excavation face and right hole excavation palm face is 18m and 24m respectively. The reasonable distance between the excavation face of the two holes in the large-section multi-arch tunnel with weak surrounding rock is 2B (the single hole excavation span is 15m).5) when the mid-guide cave-step method is used to excavate the tunnel. The influence range of the left hole construction on the stress of the middle partition wall is 18 m, and the influence range of the right hole construction on the middle partition wall stress is 27m.6. Under the original construction steps, the right side backfill is adopted at the top of the middle partition wall. In the simulation analysis of the factors affecting the stability of the partition wall, it is concluded that the backfilling on the top side of the middle partition wall is beneficial to the stability of the middle wall in the simulation analysis of the three situations of no backfilling on the top of the middle partition wall and no backfilling on the right side of the top of the middle partition wall.
【學位授予單位】：重慶交通大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：U451;U455

【參考文獻】

相關期刊論文 前6條

1 吳夢軍,連晉興,黃倫海,邱長林;連拱隧道圍巖穩(wěn)定性模型試驗[J];地下空間;2004年04期

2 馬萬權,程崇國;關于連拱隧道建設技術問題的思考[J];公路;2003年10期

3 侯朝炯,勾攀峰;巷道錨桿支護圍巖強度強化機理研究[J];巖石力學與工程學報;2000年03期

4 夏才初,劉金磊;相思嶺連拱隧道中墻應力研究[J];巖石力學與工程學報;2000年S1期

5 周玉宏,趙燕明,程崇國;偏壓連拱隧道施工過程的優(yōu)化研究[J];巖石力學與工程學報;2002年05期

6 王勝輝,杜小平,袁勇,章勇武,杜國平,劉亮;不同開挖工序對連拱隧道中墻的影響[J];巖土力學;2004年07期

，

本文編號：2014419