本文選題：隧道式錨碇　切入點：縮尺模型試驗　出處：《重慶大學》2016年碩士論文　論文類型：學位論文

【摘要】：隧道式錨碇作為目前跨江懸索大橋的重要錨碇結(jié)構(gòu)之一,其作用是將主纜錨碇于橋頭岸邊的巖石或土層中,其穩(wěn)定性直接影響著懸索橋后期運營和安全使用。橋岸庫水位上升,不僅影響庫岸邊坡的穩(wěn)定性,也對邊坡中隧道式錨碇承載力及變形產(chǎn)生影響。評估橋岸庫水位上升對隧道式錨碇安全性影響,確保其正常運營,具有重要的社會和經(jīng)濟意義。本課題依托幾江長江大橋隧道式錨碇工程,隧道式錨碇構(gòu)建于軟巖巖體之中。水對軟巖具有顯著軟化作用,為了合理評價隧道式錨碇在正常使用和長期運營過程中的安全性和穩(wěn)定性,本文以幾江長江大橋隧道式錨碇為研究對象,采用模型試驗、理論計算和數(shù)值模擬相結(jié)合的方法,研究水對隧道錨抗拔承載力及穩(wěn)定性的影響。主要研究內(nèi)容如下:1采用極限平衡理論分別推導了兩類典型隧道式錨碇破壞模式(模式一為錨碇沿著錨碇體表面拔出破壞和模式二為錨碇帶動周圍一定范圍巖體破壞)對應的承載力理論計算公式。模式一,計算幾江長江大橋隧道錨錨碇體理論極限承載力為7.58×105kN,抗滑穩(wěn)定安全系數(shù)7.01;模式二,計算天然狀態(tài)模型錨理論極限拉拔承載力為2333kN與試驗最大承載力2400kN相近。2開展兩組1:30隧道錨模型試驗(泡水狀態(tài)和天然狀態(tài)),研究模型錨泡水前、后錨碇及圍巖體在拉拔荷載下的變形狀態(tài)、極限承載能力及破壞模式,研究結(jié)果表明:泡水狀態(tài)模型錨地表測點位移和鉆孔中的測點位移總體大于天然狀態(tài)模型錨,水對模型錨變形軟化效應明顯。天然狀態(tài)模型錨極限拉拔承載力2400kN,泡水狀態(tài)極限拉拔承載力1872kN,模型錨被水浸泡后,拉拔承載能力下降幅度為22%。兩組模型錨破壞模式相似,均為倒楔形破壞。3在兩組1:30模型試驗錨成果基礎(chǔ)上,采用ABAQUS模擬兩組模型錨加載受力全過程,并結(jié)合均勻設(shè)計方法對模型錨錨區(qū)圍巖基本力學參數(shù)進行反演,獲得接近現(xiàn)場兩組模型錨試驗的圍巖力學參數(shù)。根據(jù)反演的參數(shù),利用ABAQUS對天然狀態(tài)和泡水狀態(tài)模型錨進行正向數(shù)值計算,并將兩組模型錨數(shù)值計算結(jié)果與現(xiàn)場試驗錨結(jié)果進行對比,數(shù)值計算和試驗結(jié)果比較接近,說明此種數(shù)值分析方法是可行的。4利用ABAQUS軟件研究錨區(qū)邊坡水位變化對隧道錨承載力影響,研究結(jié)果表明:從正常水位到最高洪水水位,由于水對錨碇區(qū)巖體的軟化作用,隧道錨承載力逐漸降低。在正常水位、小南海成庫后水位和最高洪水水位三種工況下,隧道錨承載力別為10P(P為單錨碇設(shè)計荷載,P=108MN)、9.24P和8.17P。在1P作用下,從正常水位到最高洪水位,隧道錨錨碇后端圍巖、錨碇拱頂上部等部位出現(xiàn)小范圍塑性區(qū),但沒有形成塑性區(qū)貫通,說明隧道錨圍巖整體處于彈性工作狀態(tài)。水位上升增大隧道錨位移和應力,但不影響隧道錨整體穩(wěn)定性。
[Abstract]:Tunnel Anchorage is one of the important Anchorage structures of suspension bridge across the river at present. Its function is to anchor the main cable in the rock or soil layer at the head of the bridge. Its stability directly affects the late operation and safe use of the suspension bridge, and the water level of the bridge bank rises. It not only affects the stability of bank slope, but also affects the bearing capacity and deformation of tunnel Anchorage in slope. It is of great social and economic significance. This subject relies on the tunnel Anchorage project of Jijiang and Yangtze River Bridge, which is constructed in soft rock mass. Water plays a significant role in softening soft rock. In order to evaluate reasonably the safety and stability of tunnel Anchorage in normal use and long-term operation, this paper takes the tunnel Anchorage of Jijiang and Yangtze River Bridge as the research object, and adopts the method of model test, theoretical calculation and numerical simulation. The main contents of this study are as follows: 1. By using the limit equilibrium theory, two typical failure modes of tunnel anchorages are derived (mode one is the anchor drawing along the surface of the anchorages), and the main contents are as follows: (1) the ultimate equilibrium theory is used to deduce two typical failure modes of tunnel anchorages. The theoretical formula for calculating the bearing capacity corresponding to the failure and mode two is the Anchorage driving a certain range of rock mass failure around the Anchorage. The theoretical ultimate bearing capacity of the tunnel Anchorage body of Jijiang and Yangtze River Bridge is calculated to be 7.58 脳 10 ~ 5kN, and the safety factor of anti-slide stability is 7.01. The theoretical ultimate drawing capacity of natural state model anchor is 2333kN, which is close to the maximum test capacity of 2400kN. 2 groups of 1:30 tunnel anchor model tests (bubble state and natural state) are carried out. The deformation state, ultimate load-carrying capacity and failure mode of the rear Anchorage and surrounding rock under pull-out load are studied. The results show that the displacement of the measured points in the Anchorage and the borehole is larger than that in the natural state model. The effect of water on deformation softening of model anchor is obvious. The ultimate drawing capacity of natural state model anchor is 2400kN, and the ultimate drawing capacity of model anchor is 1872 KN in bubble state. After the model anchor is soaked in water, the drawing-bearing capacity of model anchor decreases by 22. The failure modes of the two groups of model anchors are similar. Based on the results of two groups of 1:30 model test anchors, the whole loading process of two groups of model anchors is simulated by ABAQUS, and the basic mechanical parameters of surrounding rock in the anchor zone of the model are inversed with uniform design method. The mechanical parameters of surrounding rock near two groups of model anchors are obtained. According to the inversion parameters, the model anchors in natural state and bubble state are calculated by ABAQUS. The numerical results of the two groups of model anchors are compared with those of the field test anchors. The numerical results and the experimental results are close to each other. It is feasible to use ABAQUS software to study the influence of slope water level change on tunnel anchor bearing capacity. The results show that from normal water level to maximum flood water level, water softens the rock mass in Anchorage area. The anchoring capacity of the tunnel decreases gradually. Under the three working conditions of normal water level, post-reservoir water level and maximum flood water level in the small South China Sea, the anchoring capacity of the tunnel is different from 10 Pu P to 9. 24 P and 8. 17 P. Under the action of 1 P, the anchoring capacity of the tunnel is from normal water level to the highest flood level. The surrounding rock at the back end of the tunnel Anchorage has a small plastic zone in the upper part of the arch roof of the Anchorage, but no plastic zone is formed, which indicates that the surrounding rock of the tunnel anchor is in an elastic working state, and the rise of water level increases the displacement and stress of the anchor in the tunnel. But it does not affect the overall stability of tunnel anchor.
【學位授予單位】：重慶大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：U448.25

【參考文獻】

相關(guān)期刊論文 前10條

1 廖明進;王全才;袁從華;湯華;張水華;;基于楔形效應的隧道錨抗拔承載能力研究[J];巖土力學;2016年01期

2 龐正江;孫豪杰;賴其波;楊宜;范雷;;1∶10隧道錨縮尺模型的變形及應力特性[J];巖石力學與工程學報;2015年S2期

3 湯華;熊曉榮;吳振君;袁從華;鄧琴;;隧道錨抗拔作用機理的室內(nèi)模型試驗[J];上海交通大學學報;2015年07期

4 余家富;曹春明;;懸索橋隧道錨抗拉承載力公式探討[J];交通科技;2015年02期

5 于新華;王麗新;付環(huán)宇;梅松華;;南溪長江大橋隧道錨原位模型試驗及參數(shù)反演分析[J];科學技術(shù)與工程;2015年04期

6 喻振林;郭曉;張雄;;小南海水庫浸沒對建筑物的影響探討[J];人民長江;2014年03期

7 蔡迎春;萬超;鄭元勛;;中國自錨式懸索橋發(fā)展綜述[J];中外公路;2013年04期

8 江南;馮君;;鐵路懸索橋大噸位隧道錨承載性能分析[J];鐵道學報;2013年08期

9 代汝林;李忠芳;王姣;;基于ABAQUS的初始地應力平衡方法研究[J];重慶工商大學學報(自然科學版);2012年09期

10 周程;景鋒;邊智華;彭建國;;薄層狀灰?guī)r區(qū)大型隧道錨碇承載力特性的巖石力學綜合研究[J];中外公路;2011年06期

相關(guān)會議論文 前1條

1 胡建敏;朱杰兵;龐正江;熊贊民;;小南海水電站軟巖膨脹特性的試驗研究[A];中國巖石力學與工程實例第一屆學術(shù)會議論文集[C];2007年

相關(guān)博士學位論文 前5條

1 江南;鐵路懸索橋隧道式錨碇承載機理及計算方法研究[D];西南交通大學;2014年

2 羅少鋒;抗拔樁的承載力與變形研究[D];西安建筑科技大學;2014年

3 焦長洲;地震作用下隧道式復合錨碇動力響應分析[D];西南交通大學;2008年

4 朱玉;隧道錨設(shè)計體系中的關(guān)鍵問題研究與實踐[D];華中科技大學;2005年

5 汪海濱;懸索橋隧道式復合錨碇系統(tǒng)作用機理研究[D];西南交通大學;2006年

，

本文編號：1587396