本文選題：淺埋　切入點：大跨度　出處：《煙臺大學》2017年碩士論文　論文類型：學位論文

【摘要】：隨著我國社會經濟的不斷發(fā)展及物流運輸體系的不斷完善,高速公路的規(guī)模逐年擴大。伴隨公路設施的設計理論及施工技術水平的巨大進步,大跨度公路隧道的技術門檻降低,建設量不斷增加。對處于淺埋軟弱圍巖條件下的大跨度隧道來說,大跨且扁平的斷面形狀具有完全不同于傳統(tǒng)圓形斷面的受力特點,因而更易發(fā)生以坍塌為主的地質災害。合理的隧道開挖支護方法是處置塌方災害的首要手段,而雙側壁導坑法被證明是應用于淺埋大跨度隧道開挖支護的最理想方法。斷面跨度處于15~18m范圍內的大跨度隧道在按照雙側壁導坑法施工時,一次性開挖并支護面積較大的導坑斷面具有一定困難,故采用上下臺階法進行開挖,且經驗上不在該條件下的側壁導坑施工中添加臨時橫支撐,這一構件的缺失會嚴重影響支護結構的穩(wěn)定,引發(fā)坍塌事故。因此,研究添加臨時橫支撐的必要性及不同設置條件下臨時橫支撐的支護效果具有重要意義。以榮烏高速公路營爾嶺隧道為工程背景,通過現(xiàn)場勘察和跟進隧道施工,了解隧道淺埋段工程地質特征、工程地質評價、隧道施工方法及流程。依據(jù)地層結構法,結合有限元分析原理,使用Midas GTS NX巖土通用有限元分析軟件對營爾嶺隧道淺埋軟弱圍巖段連續(xù)集中發(fā)生的坍塌事故進行了數(shù)值模擬,并對側壁導坑開挖時導坑上臺階高度的選擇及不同結構形式臨時仰拱的支護效果進行了對比分析,得出以下結論:(1)側壁導坑分上下臺階開挖時,原設計支護結構分段施作,且未添加臨時支撐使支護結構封閉成環(huán),這是引起坍塌事故在較短距離內連續(xù)發(fā)生的主要原因。添加臨時仰拱可以抑制支護結構向洞內的滑動變形,控制沉降,改善圍巖受力條件,控制塑性區(qū)擴展,有效防止坍塌事故集中發(fā)生。(2)針對隧道左、右線來說,導坑上臺階合理高度的選擇與臨時仰拱結構形式的選擇是具有靈活性的,4m高的右洞右導坑上臺階及4.5m高的左洞左導坑上臺階采用素混凝土形式的臨時仰拱即可滿足安全需求,5m高的左洞左導坑上臺階及右洞右導坑上臺階則需要分別選擇剛度較大的20b工字鋼或鋼筋混凝土形式的臨時仰拱來滿足安全需求。
[Abstract]:With the continuous development of China's economy and logistics transportation system more perfect, the highway scale has expanded each year. With the great progress of the level of design theory and construction technology of highway facilities, technical threshold of highway tunnel with large span is reduced, the construction quantity is increasing. In the shallow and large span tunnel in soft rock under the condition. Large span and flat section shape is completely different from the traditional circular cross-section stress characteristic, so it is more prone to geological disasters to collapse mainly. Reasonable tunnel excavation method is the primary means of disposal of landslide disasters, and the double side drift method is proved to be applied in large-span shallow tunnel is ideal method of supporting the excavation of a large span tunnel span section. The range of 15~18m in accordance with the method of double side construction, excavation and supporting one-time large heading off. Some difficulties, so step method used for excavation, and the experience is not in the side heading construction under the condition of adding temporary cross support, lack of this component will seriously affect the stability of supporting structure, lead to collapse. Therefore, adding the need for temporary cross support and different setting conditions under the support of the temporary cross supporting effect has important significance. In Ying'er Rong Wu highway tunnel as the engineering background, through on-site investigation and follow up the tunnel construction, understand the geological characteristics of shallow buried section of tunnel engineering, engineering geological evaluation, construction method and process of the tunnel. Based on the stratum structure method, combined with the principle of finite element analysis, the use of Midas GTS NX geotechnical finite element analysis software of Ying'er tunnel in shallow buried soft rock section of continuous collapse was simulated, and the side heading excavation step heading height Comparing and selection of different structural forms of temporary inverted arch supporting effect, draw the following conclusions: (1) the side heading on the excavation, the original design of supporting structure for supporting section, and did not add temporary support to the supporting structure into a closed loop, which is the main cause of continuous collapse in a short distance. Add temporary inverted arch support can restrain the deformation, the sliding support structure to control the settlement, improve the surrounding rock stress condition, control the expansion of plastic zone, effectively prevent the collapse accident occurred. (2) aiming at the left tunnel, the right line, heading on the reasonable height of step structure selection and temporary invert selection is flexible, the right hole heading 4m high level and high 4.5m level with the left hole left heading temporary inverted concrete arch form can satisfy the security requirements, left heading left hole 5m high level and Right right on the stage to heading hole respectively choose temporary inverted high stiffness 20b steel or reinforced concrete arch form to meet the safety requirements.

【學位授予單位】：煙臺大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：U458.3

【參考文獻】

相關期刊論文 前10條

1 李云剛;;軟巖大斷面淺埋暗挖隧道施工工法比選數(shù)值分析[J];水利與建筑工程學報;2017年01期

2 黃倫海;錢七虎;;公路隧道大斷面改擴建施工開挖方案研究[J];現(xiàn)代隧道技術;2016年05期

3 魯?shù)梦?丁冬冬;;基于荷載結構法的某隧道襯砌結構受力特性分析[J];四川水泥;2016年09期

4 皇民;肖昭然;郭成龍;苑俊杰;;雙側壁導坑與CD法對超大斷面隧道開挖影響分析[J];交通科技與經濟;2016年04期

5 劉佳星;;膨脹土中隧道的地層—結構法數(shù)值模擬研究[J];山西建筑;2016年16期

6 劉俊;劉新榮;賴勇;何春梅;王子娟;;不同覆跨比下淺埋軟弱隧道的破壞模式[J];中南大學學報(自然科學版);2016年05期

7 昝文博;賴金星;邱軍領;張玉偉;;四車道大跨度淺埋黃土隧道開挖方案數(shù)值分析[J];解放軍理工大學學報(自然科學版);2017年01期

8 石樂;;我國高速公路建設現(xiàn)狀分析[J];合作經濟與科技;2016年08期

9 臺啟民;張頂立;房倩;齊俊;李奧;黃俊;;軟弱破碎圍巖隧道超前支護確定方法[J];巖石力學與工程學報;2016年01期

10 趙香萍;;大斷面軟弱圍巖隧道合理開挖方法研究[J];鐵道建筑技術;2015年07期

相關會議論文 前1條

1 王述紅;劉斌;朱浮聲;沙成滿;;韓家?guī)X大跨度淺埋隧道工程地質特征及其施工方法確定[A];第八次全國巖石力學與工程學術大會論文集[C];2004年

相關碩士學位論文 前6條

1 陳蒙;偏壓雙連拱隧道合理開挖與支護方式研究[D];煙臺大學;2016年

2 李玨池;淺埋軟巖隧道失穩(wěn)機理及塌方處理研究[D];重慶交通大學;2014年

3 張顯達;麻崖子特長公路隧道結構安全性評價[D];長安大學;2014年

4 齊龍飛;初期支護設計方法優(yōu)化及二次襯砌施作時機研究[D];石家莊鐵道大學;2014年

5 李海洋;高速公路軟弱圍巖隧道大變形數(shù)值模擬與應用研究[D];中國地質大學;2007年

6 王嵐;高等級公路隧道施工及監(jiān)控技術研究[D];湖南大學;2003年

，

本文編號：1571115