發(fā)布時間：2018-11-25 10:47

【摘要】：本文依托麻崖子隧道，主要研究III、IV、V級圍巖隧道結(jié)構(gòu)受力特性與安全性評價： 首先，通過現(xiàn)場的地質(zhì)預(yù)報與地質(zhì)素描，認識不同級別圍巖性質(zhì)，成功預(yù)報出Ⅴ級圍巖地段的斷層破碎帶和涌水地質(zhì)災(zāi)害；介紹規(guī)范中BQ圍巖分級，BQ分級法關(guān)鍵在于得出圍巖的單軸飽和抗壓強度RC與圍巖的完整性系數(shù)KV，借助現(xiàn)場試驗室測定巖石單軸抗壓強度，通過統(tǒng)計裸露掌子面突起部位得到節(jié)理數(shù)，介紹BQ分級方法，使我們能迅速準確地分辨圍巖的級別，及時調(diào)整開挖與支護參數(shù)。 其次，，通過對III、IV、V級圍巖地段各選擇5組斷面進行周邊收斂與拱頂下沉測試得出：其變形值隨圍巖級別的增大而增大，收斂時間與巖性、節(jié)理等因素有關(guān)；以極限位移值與位移速率為標準對圍巖變形做出評判，判定隧道的安全性；基于監(jiān)控量測數(shù)據(jù)運用位移反分析得出圍巖的力學(xué)參數(shù)，并結(jié)合設(shè)計規(guī)范給出的圍巖參數(shù)，從而確定有限元模擬時所用圍巖參數(shù)。 再次，通過在IV、V級圍巖地段埋設(shè)測試元件（包括壓力盒、鋼筋計、表面應(yīng)變計和混凝土應(yīng)變計等），對圍巖和隧道結(jié)構(gòu)受力進行量測試驗；基于對測試結(jié)果的對比與分析，找出隧道初支與二襯分擔的荷載比例，隧道襯砌內(nèi)力變化規(guī)律、受力狀況和受力薄弱部位；通過受力分析和監(jiān)控量測，對支護時機的選擇做出判斷；對V級隧道的圍巖與初支、初支與復(fù)拱、復(fù)拱與二襯分別所承擔的荷載比進行了對比。 最后，通過結(jié)合反位移法得出的參數(shù)和規(guī)范規(guī)定的參數(shù)，得出各級圍巖的模擬參數(shù)。使用有限元對其結(jié)構(gòu)與圍巖進行整體模擬，得出位移云圖和應(yīng)力云圖。利用提取的拱頂下沉值、周邊收斂值、錨桿軸力圖與現(xiàn)場測試進行校核，來分析變形趨；分別求出各級圍巖中，各施工工法所引起的周邊收斂與拱頂下沉的比例，找出各級圍巖隧道開挖中最不利工序；提取襯砌軸力、彎矩、錨桿軸力、初支剪力，求得初支與襯砌的安全系數(shù)，進而評價隧道的安全性。
[Abstract]:Based on Mayazi Tunnel, this paper mainly studies the structural stress characteristics and safety evaluation of III,IV,V class surrounding rock tunnel. Firstly, through the field geological prediction and geological sketch, we know the nature of different grade surrounding rock. The fault fracture zone and water gushing geological hazard of grade V surrounding rock are successfully predicted. This paper introduces the classification of BQ surrounding rock in the code. The key point of BQ classification method is to obtain the uniaxial saturated compressive strength of surrounding rock RC and the integrality coefficient of surrounding rock KV, to measure the uniaxial compressive strength of rock with the help of field laboratory. By counting the joints in the protruding part of the exposed face, the paper introduces the BQ classification method, which enables us to quickly and accurately distinguish the grade of surrounding rock and adjust the excavation and support parameters in time. Secondly, through the test of peripheral convergence and arch roof subsidence of 5 groups of sections selected for III,IV,V grade surrounding rock, it is concluded that the deformation value increases with the increase of surrounding rock level, and the convergence time is related to lithology, joints and other factors; Based on the limit displacement value and displacement rate, the deformation of surrounding rock is evaluated and the safety of tunnel is determined. Based on the monitoring data, the mechanical parameters of the surrounding rock are obtained by using the displacement back analysis, and the parameters of the surrounding rock are given in the design code, so as to determine the surrounding rock parameters used in the finite element simulation. Thirdly, the test elements (including pressure box, steel bar gauge, surface strain gauge and concrete strain gauge) are embedded in the surrounding rock of IV,V class to measure the stress of surrounding rock and tunnel structure. Based on the comparison and analysis of the test results, the paper finds out the load ratio of the first branch and the second lining, the law of the change of the tunnel lining internal force, the force condition and the weak position of the tunnel lining. Through the force analysis and monitoring measurement, the choice of supporting opportunity is judged, and the load ratio of surrounding rock and initial branch, initial support and double arch, double arch and second lining of V class tunnel are compared. Finally, the simulation parameters of surrounding rock at all levels are obtained by combining the parameters obtained by the reverse displacement method and the parameters specified in the specifications. The finite element method is used to simulate the structure and surrounding rock, and the displacement cloud map and stress cloud map are obtained. The deformation trend is analyzed by using the extracted dome subsidence value, peripheral convergence value, anchor shaft force and field test. The ratio of circumjacent convergence and dome subsidence caused by each construction method in surrounding rock of all levels is calculated, and the most unfavorable procedure in excavation of surrounding rock tunnel at all levels is found out. The axial force of lining, moment of bending, axial force of anchor rod and shear force of initial support are extracted, and the safety factors of initial support and lining are obtained, and the safety of tunnel is evaluated.
【學(xué)位授予單位】：長安大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：U452.12

【參考文獻】

相關(guān)期刊論文 前10條

1 吳波,高波;錨噴支護隧道圍巖穩(wěn)定性粘彈性分析及應(yīng)用[J];地下空間;2002年04期

2 馬時強;;酉水隧道圍巖大變形及支護結(jié)構(gòu)數(shù)值模擬研究[J];地下空間與工程學(xué)報;2009年03期

3 劉光明;彭立敏;施成華;丁祖德;雷明鋒;;基于結(jié)構(gòu)安全性的偏壓隧道初期支護參數(shù)優(yōu)化[J];鐵道科學(xué)與工程學(xué)報;2012年04期

4 方昱;劉開云;劉保國;;公路隧道施工期圍巖快速分級的一種新方法[J];工程地質(zhì)學(xué)報;2013年02期

5 任青文;塊體單元法及其在巖體穩(wěn)定分析中的應(yīng)用[J];河海大學(xué)學(xué)報;1995年01期

6 陳建勛;李建安;;公路隧道二次襯砌厚度的優(yōu)化[J];交通運輸工程學(xué)報;2006年03期

7 李文樺;劉保國;劉開云;陳巖;;績黃高速公路佛嶺隧道圍巖現(xiàn)場快速分級方法研究[J];路基工程;2012年01期

8 徐善初;張世林;陳建平;左昌群;;椿樹埡隧道圍巖分級的基本參數(shù)現(xiàn)場獲取方法研究[J];鐵道建筑;2011年11期

9 孫洋;陳建平;余莉;;基于力學(xué)解析法和現(xiàn)場監(jiān)控量測確定隧道二襯支護時機的應(yīng)用研究[J];鐵道建筑;2013年07期

10 葉飛;丁文其;朱合華;王旭亮;;公路隧道現(xiàn)場監(jiān)控量測及信息反饋[J];長安大學(xué)學(xué)報(自然科學(xué)版);2007年05期

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