软弱围岩隧道管棚预支护结构设计理论及应用研究

发布时间：2018-05-12 22:32

本文选题：隧道 + 管棚预支护　；参考：《重庆交通大学》2015年硕士论文

【摘要】：隧道沿途经过软弱破碎围岩等地段或处理进出口边仰坡时,为确保掌子面和地表的稳定,防止隧道塌方,控制地表沉降,增加隧道开挖时的安全性,就会面临一系列预支护围岩的特殊问题。管棚预支护是其中广泛使用的一种隧道顶部预支护措施,该技术是在拟开挖的隧道外周边钻设水平孔,然后安装钢管,再进行灌浆固结,使拱顶形成加固的伞形保护环,在该保护环的支撑下,进行循环掘进和支护施工。该技术能同时提高隧道周边围岩的强度及抗渗性能,从而保证隧道的安全施工。通过对软弱围岩隧道管棚预支护结构的受力理论及在做好超前预支护情况下掌子面稳定的研究,使修建时可以对预支护方法原理充分了解,以便对施工有个较好的指导,有利于降低工程成本及其危险性,对确保工程质量意义重大。本文的主要研究工作如下:①概述目前国内、外常用的隧道预支护技术,并且对各种类型的支护的特点进行总结与评述。②对于管棚受力荷载的计算,通过对常见计算隧道围岩压力的计算理论比较,从而借鉴这些理论当中的一些相关知识,对隧道埋深、围岩条件、开挖条件以及管棚作为预支护结构的特点等因素分析,得到相应的计算公式。③在Pasternak弹性地基梁理论的基础上创建管棚的力学分析模型,及其挠度曲线微分方程,并得到管棚支护结构的转角、弯矩及建立的求解方程,从而对管棚预支护的力学行为进行分析。④从管棚的构造、布置形式、几何参数等方面开展了管棚的优化设计方面的工作。⑤依托遵义中路隧道为工程背景,建立了管棚预支护结构模型,并进行了系统的分析。
[Abstract]:In order to ensure the stability of the face and surface, prevent the tunnel collapse, control the surface subsidence and increase the safety of the tunnel during excavation, the tunnel passes through the weak and broken surrounding rock and other places or deals with the entrance and exit slope, so as to ensure the stability of the face and surface of the tunnel. Will face a series of special problems of pre-supporting surrounding rock. The pipe shed pre-support is one of the widely used pre-supporting measures at the top of the tunnel. The technique is to drill horizontal holes around the tunnel to be excavated, then install the steel pipe, and then grouting consolidation, so that the vault can form a reinforced umbrella protection ring. Under the support of the protective ring, circular tunneling and supporting construction are carried out. The technique can improve the strength and impermeability of surrounding rock around the tunnel at the same time, so as to ensure the safe construction of the tunnel. Through the research on the stress theory of the pipe shed pre-supporting structure of soft surrounding rock tunnel and the stability of the foreface under the condition of advanced pre-support, the principle of the pre-support method can be fully understood when it is built, so as to give a better guidance to the construction. It is beneficial to reduce the project cost and its danger, and it is of great significance to ensure the engineering quality. The main research work of this paper is as follows: 1: 1 summarizes the current domestic and foreign tunnel pre-support technology, and summarizes and comments on the characteristics of various types of support. By comparing the common calculation theories of surrounding rock pressure of tunnel, and using some relevant knowledge of these theories for reference, the factors such as tunnel depth, surrounding rock condition, excavation condition and the characteristics of pipe shed as pre-supporting structure are analyzed. Based on the theory of Pasternak elastic foundation beam, the mechanical analysis model of pipe shed and the differential equation of deflection curve are obtained, and the rotation angle, bending moment and solving equation of pipe shed supporting structure are obtained. Based on the analysis of the mechanical behavior of the pipe shed pre-support, the author carried out the optimization design of the pipe shed from the aspects of the structure, layout form and geometric parameters of the pipe shed. 5. 5 based on the Zunyi Middle Road Tunnel as the engineering background. The model of pipe-shed pre-supporting structure is established, and the systematic analysis is carried out.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.7

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