偏压条件下小净距隧道力学特性研究
偏压条件下小净距隧道力学特性研究(任务书,开题报告,论文15000字)
摘要
我国交通基础设施建设的快速发展，极大地促进了大量的隧道工程的应用，受到了地形地质、线路等条件的制约，不得不在浅层和靠近山坡的地方修建隧道，所以不可避免地出现越来越多的浅埋偏压隧道。不同于所见常规隧道，偏压隧道的结构受力情况更为复杂，施工难度程度也更大。隧道在修建的过程将会多次扰动围岩，导致围岩应力多次的重分布，其结构受力比较复杂，施工过程中若稍有不慎将会发生塌方等严重事故。因此确定隧道的围岩应力和破坏机理是设计施工和安全运营的关键问题。
在我国高速公路建设发展过程中，小净距的隧道出现的形式越来越多。以广东江罗高速大石岭隧道为研究背景，运用理论分析和数值模拟这两种方法对不同偏压角度下小净距隧道受力和变形规律进行研究，同时分析得出隧道开挖后围岩塑性区的分布特征，为大石岭隧道施工质量和施工安全提供一定的技术保障。本文的主要研究内容包括：
(1)总结偏压小净距隧道的破坏机理及破坏基本模式，分析偏压小净距隧道围岩压力计算理论和方法、围岩压力分布特点；
(2)以隧道的弹塑性理论及其相关力学理论为基础，运用数值模拟软件，对所选取的隧道围岩控制点的位移、应力与偏压角度的关系进行深入的分析，探讨偏压小净距隧道围岩受力变形特征和规律；
(3)给出不同偏压条件下小净距隧道之间的相互影响规律，同时依据相关理论知识进行分析，对偏压小净距隧道的设计和施工提出几点建议，以期望可以作为相关工程人员的参考。
关键词：偏压小净距隧道；数值模拟；ANSYS；围岩变形受力
Abstract
The rapid development of China's transportation infrastructure vigorously promote the wide application of tunnel engineering, influenced by geological terrain, alignments, and other conditions,It is inevitable to build a tunnel near the slope and with a shallow depth, which inevitably appears more and more shallow buried bias tunnels. Different from the conventional tunnel, the bias tunnel structure is more complex, the construction is more difficult.The construction process of the tunnel to be made will make the surrounding rock disturbed many times, the surrounding rock stress repeatedly re distribute, and the structure is complex, the construction of a slight accident and other serious accidents will be a landslide .How to accurately determine the pressure and failure mechanism of the surrounding rock is a key problem in the construction and long-term operation safety.
In the highway construction in our country, neighborhood tunnel is adopted more and more. Based on Dashiling tunnel of Jiangluo expressway in Guangdong province, the paper study on the stress state and deformation law of tunnel under different bias conditions by theoretical analysis and the combined method of numerical simulation, and analysis of the distribution characteristics of plastic zone of surrounding rock after excavation of tunnel, to provide technical guarantee for the construction quality and construction safety of the Dashilingtunnel.The main research contents of this paper include:
(1)The failure mechanism and failure mode of the unsymmetrical pressure tunnel with small spacing are summarized, and the theory and method of calculating the pressure of surrounding rock are analyzed, and the distribution characteristics of the surrounding rock pressure are analyzed.
(2)Based on the theory of tunnel and the theory of elastic plasticity,using the numerical simulation software, the relationship between the displacement of surrounding rock control point, the stress and the bias angle of the tunnel surrounding rock is analyzed, to discuss on the deformation characteristics and law of the surrounding rock of the tunnel with unsymmetrical pressure.
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(3) Given the mutual influence of neighborhood tunnel under different bias conditions, combined with theoretical knowledge related to the analysis, Some suggestions on the design and construction of the low voltage and small spacing tunnel are put forward, expecting to be used as a reference for the related engineering personnel.
Key Words：biasneighborhood tunnel；numerical simulation；ANSYS；deformation and stress of surrounding rock
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目录
摘要 II
Abstract III
1绪论 1
1.1问题的提出及研究意义 1
1.2国内外研究现状及存在的问题 2
1.2.1国内外研究现状 2
1.2.2存在的问题 3
1.3本文主要研究内容和技术路线 4
1.3.1研究的主要内容 4
1.3.2研究技术路线 4
2偏压小净距隧道围岩压力计算理论及分布特点 6
2.1概述 6
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2.2浅埋偏压的判定 6
2.2.1小净距隧道深浅埋的判定 6
2.2.2隧道偏压形成原因 7
2.3浅埋偏压小净距隧道围岩压力计算 7
2.3.1基本假定 8
2.3.2计算公式推导 9
2.3.3不同偏压角度下围岩压力分析 12
2.4本章小结 13
3偏压小净距隧道力学特性分析 14
3.1概述 14
3.2工程背景 14
3.2.1工程概况 14
3.2.2水文与地质情况 14
3.3 ANSYS在隧道开挖模拟的应用 15
3.3.1初始地应力及其平衡 15
3.3.2单元生死模拟开挖 16
3.4模型的建立 16
3.4.1基本假定 16
3.4.2模型及其参数的选取 16
3.4.3重点分析部位选择 18
3.5数值模拟分析 18
3.5.1不同偏压角度下围岩位移变化分析 18 [资料来源：http://doc163.com]
3.5.2不同偏压角度下围岩应力变化分析 21
3.5.3不同偏压角度下围岩塑性区分析 23
3.6本章小结 25
4结论与展望 26
4.1结论 26
4.2存在的问题及展望 26
致谢 28
参考文献 29 [资料来源：https://www.doc163.com]