本文選題：巖堆體隧道　切入點(diǎn)：理論分析　出處：《昆明理工大學(xué)》2015年碩士論文

【摘要】：云南山區(qū)巖堆體分布廣泛,在隧道建設(shè)中常遇到巖堆體這種不良地質(zhì),給隧道施工帶來(lái)了諸多困難,如引起隧道坍方、襯砌開(kāi)裂、地表變形及滑坡等,影響施工進(jìn)度和安全。隨著西部山區(qū)公路建設(shè)的快速發(fā)展,穿越巖堆體隧道日益增多,亟待解決和巖堆相關(guān)的工程地質(zhì)問(wèn)題,以實(shí)現(xiàn)巖堆體隧道的快速、安全施工。本文依托麻昭高速公路沿線巖堆體隧道工程,在總結(jié)巖堆體工程特性的基礎(chǔ)上,采用理論分析、數(shù)值計(jì)算和現(xiàn)場(chǎng)實(shí)測(cè)相結(jié)合的方法,對(duì)巖堆體隧道洞口段的開(kāi)挖進(jìn)尺、三臺(tái)階七步工法中的臺(tái)階長(zhǎng)度、鎖腳錨桿長(zhǎng)度與斜插角度等施工參數(shù)進(jìn)行了研究分析,給出了巖堆體隧道洞口淺埋段的較優(yōu)施工參數(shù)。主要研究?jī)?nèi)容及成果如下：(1)結(jié)合麻柳灣-昭通高速公路沿線的巖堆體情況,分析了巖堆體特征、形成條件及工程特性,總結(jié)了國(guó)內(nèi)典型巖堆體隧道的施工參數(shù)和施工控制措施。(2)基于彈性地基梁理論、太沙基理論及筒倉(cāng)理論,提出了巖堆體隧道洞口淺埋段優(yōu)化開(kāi)挖進(jìn)尺的計(jì)算模型,進(jìn)行了不同情況下隧道洞口段的施工進(jìn)尺的優(yōu)化分析。結(jié)果表明在采用管棚支護(hù)下,合理開(kāi)挖進(jìn)尺為1.0m左右。(3)采用Midas-NX有限元軟件,建立了巖堆體隧道洞口淺埋段的多工況三維數(shù)值計(jì)算模型,完成了巖堆體隧道洞口淺埋段三臺(tái)階七步法施工過(guò)程的三維仿真計(jì)算,系統(tǒng)分析了不同施工參數(shù)下隧道圍巖及支護(hù)結(jié)構(gòu)的受力變形規(guī)律,并與現(xiàn)場(chǎng)測(cè)試結(jié)果進(jìn)行了比較。結(jié)果表明：1)隨著臺(tái)階長(zhǎng)度的增加,隧道圍巖豎向位移以及水平收斂值均隨之變大,而鋼拱架承受的軸力和彎矩值均逐漸減小,噴射混凝土層承受的拉應(yīng)力也隨之減小。綜合圍巖變形和支護(hù)結(jié)構(gòu)受力情況,巖堆體隧道洞口淺埋段臺(tái)階長(zhǎng)度宜取4m左右。2)隨著鎖腳錨桿插入角度的增大,不同部位的水平位移變化規(guī)律相當(dāng),上臺(tái)階水平位移呈逐漸減小趨勢(shì),中、下臺(tái)階水平位移呈先減小后增大趨勢(shì)。鎖腳錨桿的斜插角度均宜取20°-30°。3)隨著鎖腳錨桿長(zhǎng)度的增加,拱腳和邊墻以及墻腳處的水平位移隨之減小,當(dāng)錨桿長(zhǎng)度超過(guò)4.5m后,水平位移減小幅度趨于平緩。鎖腳錨桿長(zhǎng)度宜取4.5m-6m。
[Abstract]:The rock heaps are widely distributed in the mountainous areas of Yunnan Province. The bad geology of rock heaps is often encountered in the tunnel construction, which brings many difficulties to the tunnel construction, such as causing tunnel collapse, lining cracking, surface deformation and landslide, which affect the construction progress and safety.With the rapid development of highway construction in the western mountainous area, there are more and more tunnels passing through the rock pile. The engineering geological problems related to the rock pile are urgently needed to be solved in order to realize the rapid and safe construction of the tunnel.On the basis of summing up the characteristics of rockfill tunnel along Ma-Zhao Expressway, this paper adopts the method of combining theoretical analysis, numerical calculation and field measurement to excavate the tunnel entrance of rockpile tunnel.The construction parameters, such as the length of step, the length of anchor bolt and the angle of inclined insertion, in the three-step and seven-step construction method are studied and analyzed, and the optimum construction parameters of shallow burying section at the entrance of rock pile tunnel are given.The main research contents and results are as follows: (1) combined with the rock mass along the Maaliu-Zhaotong Expressway, the characteristics, forming conditions and engineering characteristics of the rock pile are analyzed.Based on the theory of elastic foundation beam, Taishaji theory and silo theory, the calculation model of optimum excavation advance of shallow buried section of rock pile tunnel is put forward, which is based on the theory of elastic foundation beam, the theory of Taishaji and the theory of silo.The optimum analysis of the construction advance of the tunnel entrance section under different conditions is carried out.The results show that under the support of pipe-shed, the reasonable excavation scale is about 1.0 m. The Midas-NX finite element software is used to establish the multi-condition three-dimensional numerical model of shallow buried section of the tunnel entrance of the rockpile tunnel.The three-dimensional simulation calculation of the construction process of the three-step and seven-step method for shallow burying section of rock pile tunnel is completed. The law of stress and deformation of surrounding rock and supporting structure of tunnel under different construction parameters are analyzed systematically, and the results are compared with the field test results.The results show that with the increase of step length, the vertical displacement and horizontal convergence of surrounding rock become larger, while the axial force and bending moment of steel arch gradually decrease, and the tensile stress of shotcrete layer decreases.Considering the deformation of surrounding rock and the stress of supporting structure, the length of step in shallow buried section of rock pile tunnel should be about 4m. 2) with the increase of the angle of bolt insertion, the horizontal displacement of different parts is the same.The horizontal displacement of the upper step decreases gradually, and the horizontal displacement of the lower step decreases first and then increases.With the increase of the length of locking bolt, the horizontal displacement of arch foot, side wall and the foot of wall decreases. When the length of anchor rod exceeds 4.5 m, the horizontal displacement decreases slightly.The length of locking bolt should be 4.5m-6m.
【學(xué)位授予單位】：昆明理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：U455.4

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 滿帥;孔超;王海彥;;隧道洞口淺埋段管棚超前支護(hù)開(kāi)挖進(jìn)尺優(yōu)化[J];鐵道標(biāo)準(zhǔn)設(shè)計(jì);2013年10期

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本文編號(hào)：1712989