上跨隧道对既有隧道的变形影响及控制研究

发布时间：2018-01-12 17:29

本文关键词：上跨隧道对既有隧道的变形影响及控制研究　出处：《重庆交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着人口不断的涌向城市、交通堵塞日益的严重，交通隧道及其他地下市政工程已经开始了大量的建设。然而地下空间资源也是有限的，新建隧道上跨既有隧道的情况日益增多。新建隧道的施工肯定会扰动其周围的土体，进而引起近接的既有隧道结构位移的变化与内力的改变。目前工程界在上跨工程作用于既有隧道上的力学机理方面还没深入的研究，保护既有隧道的控制指标也没有相应的规范。本文重庆两江大桥渝中连接隧道上跨既有地铁六号线为背景，通过对上跨隧道与既有隧道的相互作用机理分析，结合有限元数值模拟计算、现场监控量测手段，对位于渝中连接隧道明挖和暗挖区间段下方的既有隧道进行了位移和受力的研究，并对上跨隧道影响既有隧道的关键参数进行了研究与探讨。本文的主要研究内容如下： ①总结并提炼了各种近接隧道理论研究成果与施工工法。 ②深入分析了上跨隧道对既有隧道的作用机理，明确了夹层土体对跨越工程的重要性。 ③建立了二维实体1:1的数值模型，研究了明挖段与暗挖段处上跨隧道施工时既有隧道的支护结构（初期支护、二次衬砌）的位移、应力的变化以及塑性区的改变。并对比了上跨隧道先右洞施工和先左洞施工两种工况下既有隧道的受力情况，论证了两种工法都可以保证既有地铁隧道的安全。 ④对位于渝中连接隧道下部的地铁六号线进行了监控量测（拱顶沉降、周边收敛），并把监测结果与有限元数值模拟计算结果进行了对比，证明本次的数值模拟过程与结果都是可靠的。 ⑤对上跨隧道影响既有隧道的关键参数（两隧道间的偏移距离、夹层土体厚度）进行了研究，总结了既有隧道内力的改变随两隧道间偏移距离与夹层土体厚度改变而改变的规律。 ⑥参考了国内外上跨隧道施工中为保护既有隧道正常运营而采取的控制指标，结合《混凝土结构设计规范》，对当前的工程提出了几点控制建议。并总结了一些近接施工中为保护既有隧道而采取的措施。
[Abstract]:Along with the continuous population into the city, traffic congestion is serious, traffic tunnels and other underground municipal engineering has already begun construction. However a large number of underground space resource is limited, the new tunnel on existing tunnel span increasing. The construction of a new tunnel to the surrounding soil disturbance will change, causing nearly then both change and the internal force and displacement of tunnel structure. In current engineering field in cross project on both the mechanical mechanism of tunnel has been studied, control index of protection of existing tunnel and no corresponding standard.
The two rivers in Chongqing Yuzhong bridge connecting Tunnel Crossing Existing Metro Line six as the background, through the analysis of the interaction mechanism of the cross tunnel and existing tunnel, combined with finite element numerical simulation, field monitoring means, located in Yuzhong connecting tunnel digging and mining area between the bottom section of existing tunnel the displacement and stress of the research, the key parameters and the effect of the cross tunnel tunnel has been studied and discussed.
The main contents of this paper are as follows:
(1) the theoretical research results and construction methods of various tunnels are summarized and refined.
Secondly, the effect mechanism of the tunnel on the existing tunnel is deeply analyzed, and the importance of the interlayer soil to the crossing project is clearly defined.
To establish the numerical model of 1:1 2D entity, on the open excavation section and excavation section cross tunnel construction on existing tunnel supporting structure (two lining initial supporting) displacement, stress change and the change of the plastic zone. And compared across the first tunnel right hole the first left hole construction and construction under two conditions of existing tunnel stress, demonstrates two kinds of method can not only ensure the safety of the metro tunnel.
(4) monitoring and measuring (crown settlement and peripheral convergence) of metro line six located at the lower part of Yuzhong connecting tunnel. The monitoring results are compared with those of finite element numerical simulation, which proves that the numerical simulation process and results are reliable.
(5) the key parameters affecting the existing tunnel, including the distance between the two tunnels and the thickness of the interlayer soil, have been studied. The law of the change of the internal force of the existing tunnel has been changed along with the offset distance between the two tunnels and the thickness of the sandwich soil.
The reference to the control index of domestic and foreign cross tunnel construction in order to protect the normal operation of the existing tunnel and take the combination of "code for design of concrete structures", some suggestions on the current control engineering is put forward. And summarizes some close construction for the protection of the existing tunnel and take measures.

【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U451

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