【作者】 陈晓江；

【导师】 刘新荣；

【作者基本信息】 重庆大学 ， 岩土工程， 2005， 硕士

【摘要】 近年来,随着高等级公路建设的不断发展,隧道的数量日益增多。连拱隧道具有线形流畅,空间利用率高,占地面积较少,与洞外线路连接方便等优点,得到了越来越多的应用。中隔墙作为连拱隧道的核心结构,在隧道的施工过程中要经历多次扰动和应力从分布,具有复杂的受力形式。目前,专门对中隔墙作的数值模拟计算还很少,在已有的实例中一般是将连拱隧道整体作为主要分析对象,对中隔墙的研究还不够全面。为了解和掌握连拱隧道中隔墙在隧道施工过程中受力及相应应力与位移的特点,本文以我国首例黄土连拱隧道——离石连拱隧道为实际背景,应用ANSYS 有限元程序,建立了三个二维平面弹塑性有限元模型,通过模拟开挖过程的数值计算,得到了不同截面形式和尺寸的中隔墙在不同中墙基础条件下的应力分布规律和位移情况,对直中墙和曲中墙的受力特点做了比较分析,提出了优化中墙尺寸的一些看法。另外本文还建立了三维空间有限元非线性弹塑性模型,通过数值计算得到了在施工过程中,中隔墙空间效应、左右洞的相互影响,以及墙体结构的应力分布规律及稳定性。最后通过分析离石连拱隧道中墙监控量测得到的第一手实测数据,来验证数值分析结果的可靠性。更多还原

【Abstract】 In the last few years, with the development of highway, the number of tunnels has evidently increased. Bi-arch tunnels, which have the advantage of smooth line type, higher use factor of space, lower land occupancy, and been convenient for the tunnels to connect with the way out of the tunnels, have been adopted in the highway project increasingly. The mid-partition, as the core structure of Bi-arch tunnel, will come through some kind of disturbance and stress redistributing in the process of tunnel’s construction. At present, there are still few studies of numerical simulation specialized in the mid-partition. Notwithstanding that some thesis have studied the bi-arch tunnel, they didn’t analyzed the mid-partition comprehensively. In order to find out the situation of mid-partition’s stress and deformation under each phase of the predetermined excavating technique, the paper used the FEM soft of ANSYS to establish three elastoplastic FEM 2-D plan models based on the Li shi Bi-arch Tunnel Project, which is the first constructed Bi-arch tunnel in loess stratum of China .By the numerical calculation of simulating the tunnel’s excavating process, the paper gains the distribution law of mid-partition’stress and deformation corresponding to different section figures, geometrical measures and diverse foundation performance. And the paper also compared the mechanics characteristic of flectional mid-partition with the erect mid-partition, thus brought forward the opinions about the optimization techniques of the mid-partition’s geometrical measures. Further more, the paper established a perfect nonlinear elastoplastic FEM 3-D model, and gained the mid-partition’s dimensional effect ,distribution law of stress and deformation, interaction of the left and right cavity and stability through the numerical calculation of simulating the tunnel’s excavating process. Finally the paper analyzed the factual datum collected from the site of Li shi Bi-arch Tunnel so as to validate the result of the numerical simulation.更多还原