隧道二次衬砌合理支护时机问题研究

发布时间：2018-02-02 07:33

  本文关键词： 隧道二衬 支护时机 监控量测 隧道开挖 三维模拟　出处：《重庆交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：新奥法由于能有效地利用围岩本身支承能力,使围岩和支护结构共同作用,能有效地克服冒顶和局部塌方等事故,并且由于支护结构包括初次支护和二次衬砌,大大提高了隧道防水效果和安全储备,因此在隧道修建中得到了广泛应用。而隧道二次衬砌的施工则是隧道施工中的重中之重,确定合理的二衬施作时间对充分发挥围岩的自承能力、隧道洞室开挖的经济和安全性具有重要意义。本文对隧道二次衬砌的施作时间主要进行了以下的研究： ①对现在国内外的研究现状进行分析,并对隧道二衬的支护时机的确定机理进行了分析,以及介绍了隧道二衬支护时机的研究方法,主要是弹塑性解析法、工地实测数据分析法以及隧道模型的模拟分析法。 ②本文以重庆市轨道交通6号线中梁山隧道为依托,对隧道的拱顶沉降以及周边收敛进行监控量测,并对监控量测的数据进行分析。主要看隧道开挖时,拱顶沉降以及周边收敛的累计变形量,以及数据的收敛情况。 ③用大型有限元软件ANSYS对隧道进行三维开挖模拟,对隧道的Ⅲ、Ⅳ以及V级围岩计算其变形情况,主要是计算隧道的水平向位移以及竖直向位移,也即是隧道的周边收敛以及拱顶沉降,并将其结果与中梁山隧道的监控量测结果进行对比分析,最终得出隧道二衬支护的最佳时机。 取得结果主要如下： ①选取的具有代表性的Ⅲ级围岩断面,在开挖后29天左右变形达到稳定,变形数据及曲线已收敛,此时可以施作隧道的二衬。 ②选取的具有代表性的Ⅳ级围岩断面,在开挖后32天左右变形达到稳定,变形数据及曲线已收敛,此时可以施作隧道的二衬。 ③选取的具有代表性的Ⅴ级围岩断面,在开挖后37天左右变形达到稳定,变形数据及曲线已收敛,此时可以施作隧道的二衬。
[Abstract]:Because of the effective use of the supporting capacity of surrounding rock and the joint action of surrounding rock and supporting structure, the method can effectively overcome the accidents such as roof fall and local collapse, and the supporting structure includes primary support and secondary lining. It greatly improves the waterproof effect and safety reserve of the tunnel, so it is widely used in the tunnel construction, and the construction of the second lining of the tunnel is the most important in the tunnel construction. It is of great significance to determine the reasonable second lining construction time for giving full play to the self-supporting capacity of surrounding rock and for the economy and safety of tunnel tunnel excavation. In this paper, the author mainly studies the construction time of tunnel secondary lining as follows:. The main contents are as follows: 1. The present research situation at home and abroad is analyzed, and the mechanism of determining the supporting opportunity of the second lining of tunnel is analyzed, and the research method of the supporting opportunity of the second lining of tunnel is introduced, mainly the elastic-plastic analytical method. Site measured data analysis and tunnel model simulation analysis. 2. Based on Zhongliangshan tunnel of Chongqing rail transit line 6, this paper carries on the monitoring measurement to the tunnel dome settlement and the peripheral convergence, and analyzes the data of the monitoring measurement, mainly looking at the tunnel excavation. The cumulative deformation of the dome settlement and its peripheral convergence, as well as the convergence of the data. (3) the 3D excavation simulation of the tunnel is carried out by using the large-scale finite element software ANSYS. The deformation of the tunnel's 鈪，

本文编号：1483990