摘 要

本文借助了有限元分析软件Midas gts/nx，以湖北省宜昌市境内伍家岗长江大桥北岸的隧道锚结构为研究对象，对隧道锚进行了几何建模，对不同开挖方案和台阶法下的不同开挖进尺进行了三维数值施工模拟，比较了全断面法和台阶法对开挖隧道的影响规律。模拟结果表明，台阶法开挖隧道更具安全性和可行性，这对隧道锚的实际开挖具有重要的支持与指导意义，保证开挖质量和安全。

论文主要研究了隧道锚结构在完成三维建模后，运用全断面法和台阶法，以及在不同开挖进尺下进行的开挖模拟过程，分析比较了开挖所得的力学特性及拱顶沉降量规律。

研究结果表明，运用台阶法开挖对整个隧道锚周围的岩土影响较小。与全断面相比，台阶法开挖引起的力学响应相对更小，应力分布更均匀，整体结构更稳定。台阶法的开挖进尺越大，当下开挖引起的沉降量占总沉降量比值越大，诱发围岩失稳的概率也更大。开挖进尺越小，则开挖的次数相应增多，对围岩的干扰次数也越多，最后累计的沉降量也较大。

本文的特色是运用有限元分析软件Midas，对实际施工进行模拟。

关键词： 隧道锚 台阶法 全断面法 开挖进尺 模拟

Abstract

With the assistance of finite element analysis software MIDAS GTSNX, this paper takes the tunnel anchor structure on the North Bank of the Wujiagang District Yangtze River bridge in Yichang City, Hubei Province as the object of the study, and carries out the geometric modeling of the tunnel anchor, in this paper, three-dimensional numerical construction simulation is carried out for different excavation schemes and different excavation footage, and the influence of full-section method and step method is compared. The simulation results show that the bench method is more safe and feasible, which has significant support and guidance significance for the actual excavation of tunnel anchor and ensures the quality and safety of excavation.

The paper mainly studies the whole section method and step method, and the excavation simulation process under different excavation footage after the completion of 3D modeling of the tunnel anchor structure, the mechanical properties and the settlement law of the arch crown are analyzed and compared.

The results show that the step method has small impact on the surrounding rock and soil of the whole tunnel. Compared with the whole section, the mechanical response induced by the step method is smaller, the stress distribution is more uniform and the whole structure is more stable. The larger the excavation advance of step method is, the larger the ratio of settlement to total settlement at present, and the greater the probability of inducing surrounding rock instability. The smaller the excavation footage, the more the excavation times, the more the disturbance times to the surrounding rock, and the larger the final accumulated settlement.

The characteristic of this paper is to imitate the actual construction with finite element analysis software MIDAS.

Keywords: tunnel anchor bench cut method full face excavation method footage of excavation imitate

目 录

第一章 绪论...................................................................................................................................1

1.1 研究背景及意义..............................................................................................................2

1.1.1 课题来源...............................................................................................................2

1.1.2 研究背景...............................................................................................................2

1.1.3 研究意义................................................................................................................2

1.2 国内外关于隧道锚施工的研究现状..............................................................................3

1.2.1 国外研究现状.......................................................................................................3

1.2.2 国内研究现状. .....................................................................................................5

1.3 本文的研究内容和研究方法..........................................................................................6

第二章 隧道锚施工涉及的理论知识...........................................................................................7

2.1 隧道锚概述.. ...................................................................................................................7

2.1.1隧道锚的定义.........................................................................................................7

2.1.2隧道锚开挖.............................................................................................................7

2.1.3隧道锚支护.............................................................................................................7

2.1.4隧道锚的适用条件.................................................................................................7

2.2伍家岗长江大桥北岸隧道锚工程概况..........................................................................8

第三章 隧道开挖方案与有限元软件Midas.................................................................................9

3.1 隧道开挖方法..................................................................................................................9

3.1.1 用台阶法开挖隧道...............................................................................................9

3.1.2 用全断面法开挖隧道..........................................................................................10

3.2 有限元分析软件Midas（迈达斯）..............................................................................10

3.2.1 Midas简介............................................................................................................10

3.2.2 利用Midas软件建模..........................................................................................11

第四章 数值模拟.........................................................................................................................20

4.1不同开挖方案模拟.........................................................................................................20

4.1.1 全断面法开挖模拟.............................................................................................20