软弱围岩大断面隧道台阶法施工技术参数研究

发布时间：2018-04-10 14:50

本文选题：隧道 + 大断面软弱围岩　；参考：《北京交通大学》2014年硕士论文

【摘要】：在山岭隧道软弱围岩隧道的开挖工法中,由台阶法延伸出的三台阶七步开挖工法因其独特的优势,应用越来越多。然而对于三台阶七步工法的主要施工参数研究还不够深入,这仍是软弱围岩大断面隧道中亟待进一步研究的重要课题。本文以吉林省延吉地区富岩1号隧道(V级围岩)为工程背景,通过理论分析与数值模拟相结合的研究方法对V级大断面软弱围岩的施工技术方案和技术参数进行了研究,为本项目和相关隧道工程的设计施工提供一定的借鉴和指导作用。主要研究内容包括： (1)总结软弱围岩大断面隧道的分类标准、发展现状和基本力学特征,分析三台阶七步开挖法在软弱围岩大断面隧道中的适用性,为研究三台阶七步开挖的施工技术参数做铺垫； (2)介绍三台阶七步开挖法的施工工艺,确定主要研究的施工技术参数为台阶长度和上台阶高度,选择不同工况进行数值模拟,得到三台阶七步开挖工法下隧道的各方向位移、初喷混凝土的第一主应力、钢拱架和锁脚锚管的最大压应力结果,并进行对比分析获得所研究施工参数对隧道的影响规律； (3)在研究了台阶长度和上台阶高度对初期支护变形和受力的影响规律后,本文进一步研究了开挖进尺的增大对隧道的影响,并选取了同时改变两个施工参数的多个工况,对参数的组合进行数值模拟,得到不同工况下的隧道的变形和受力。通过对不同工况的模拟结果进行对比分析,可以得到参数组合变化对隧道的影响规律。对比参数组合时,目的是在隧道的变形和位移没有增加的前提下,开挖进尺可以得到增加,开挖进尺增大就有利于缩短工期,降低成本。
[Abstract]:In the excavation method of weak surrounding rock tunnel in Shanling tunnel, the three-step seven-step excavation method extended from step method has been applied more and more because of its unique advantages.However, the study on the main construction parameters of the three-step and seven-step construction method is not deep enough, which is still an important subject for further study in the large-section tunnel of weak surrounding rock.Based on the engineering background of Fuyan No. 1 tunnel in Yanji region of Jilin Province, this paper studies the construction technical scheme and technical parameters of soft surrounding rock of V-class large section by combining theoretical analysis with numerical simulation.To provide some reference and guidance for the design and construction of this project and related tunnel engineering.The main research contents include:1) summing up the classification standard of large section tunnel of soft surrounding rock, developing present situation and basic mechanical characteristics, analyzing the applicability of three-step and seven-step excavation method in large-section tunnel of soft surrounding rock, paving the way for studying the construction technical parameters of three-step and seven-step excavation;The construction technology of three-step and seven-step excavation method is introduced. The main construction technical parameters are determined as step length and step height. Different working conditions are selected for numerical simulation, and the displacement of each direction of the tunnel under the three-step seven-step excavation method is obtained.The first principal stress of initial shotcreting concrete, the maximum compressive stress of steel arch frame and anchor pipe with locking foot are obtained, and the influence of the construction parameters on the tunnel is obtained by comparing and analyzing.After studying the influence of the length of step and the height of upper step on the deformation and force of the initial support, this paper further studies the influence of the increase of the scale of excavation on the tunnel, and selects several working conditions that change the two construction parameters simultaneously.Numerical simulation of the combination of parameters is carried out to obtain the deformation and force of the tunnel under different working conditions.By comparing and analyzing the simulation results of different working conditions, the influence of the parameter combination on the tunnel can be obtained.When comparing the parameters, the aim is that the excavation advance can be increased without increasing the deformation and displacement of the tunnel, and the increase of the excavation advance will help to shorten the construction period and reduce the cost.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U455.4

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