城市地铁大断面隧道施工监测分析与风险评估研究

发布时间：2018-03-13 01:05

本文选题：大断面隧道　切入点：监测数据　出处：《南昌航空大学》2017年硕士论文　论文类型：学位论文

【摘要】：城市地铁的修建已成为当前城市高速化发展的重要标志。伴随着地铁的“高、大、宽、浅”发展趋势,大断面隧道不断涌现。为提高地铁的便捷性,不可避免地出现上下交叉的隧道,这也扩大了新建隧道与已有隧道之间的相互影响。探究大断面隧道及其与临近隧道间的相互影响已成为地下工程研究的重要内容。本文以哈尔滨地铁一期工程“哈尔滨南站至农科院站”区间的临近隧道的大断面隧道为背景,对施工过程中隧道围岩变形进行施工监测和数值模拟,并对隧道施工安全风险进行评估。主要的研究内容为:(1)对现场监测数据进行整理,得到了地表沉降、拱顶沉降和水平收敛的变化曲线图,并对变化规律进行了分析。结果表明:地表沉降具有一定的规律,基本符合Peck沉降曲线图;拱顶沉降与地表沉降表现出了一致性;先开挖的导洞最终沉降量最大,说明开挖其他导洞时对该位置沉降有一定的影响。(2)采用ANSYS软件对大断面隧道的双侧壁导坑法的施工过程进行了数值模拟,分析了在对每个导洞开挖时,土体和初期支护的位移和应力的变化状态。研究表明:中上导洞开挖时引起的地表沉降、拱顶沉降和水平收敛变化量最大,且应力比较大的区域主要在拱顶、拱腰和拱脚部分。(3)通过对现场隧道风险辨识可知,临近隧道之间的影响是施工风险评估的重点对象。据此应用肯特指数法和模糊数学法对临近隧道的隧道施工风险等级进行了分析和评估。两种方法的风险评估结果均为中度,说明两种方法在评估结论上具有一致性。
[Abstract]:The construction of urban subway has become an important symbol of the high-speed development of the city. With the development trend of "high, large, wide and shallow" of subway, large-section tunnels are emerging constantly. Inevitably, there are tunnels that intersect up and down, This also expands the interaction between the new tunnel and the existing tunnel. Exploring the interaction between the large-section tunnel and its adjacent tunnel has become an important part of the underground engineering research. The large-section tunnel adjacent to the tunnel in the section from Harbin South Station to the Academy of Agricultural Sciences station is the background. The construction monitoring and numerical simulation of tunnel surrounding rock deformation are carried out, and the safety risk of tunnel construction is evaluated. The main research contents are as follows: 1) the site monitoring data are sorted out, and the surface subsidence is obtained. The curve of the vault settlement and horizontal convergence is analyzed. The results show that the surface subsidence has certain rules, which basically accords with the Peck curve, and the dome settlement is consistent with the surface settlement. The final settlement of the first excavated pilot tunnel is the largest, which indicates that the settlement of this position is affected by the excavation of other guideways. (2) the construction process of double-sidewall diversion pit method of large-section tunnel is numerically simulated by using ANSYS software. The variation of displacement and stress of soil mass and initial support during excavation of each pilot tunnel is analyzed. The results show that the surface settlement, vault settlement and horizontal convergence change are the largest during the excavation of the middle and upper pilot tunnel. And the area where the stress is relatively large is mainly in the arch roof, arch waist and arch foot part. The influence between adjacent tunnels is the key object of construction risk assessment. Based on the analysis and evaluation of tunnel construction risk grade by using Kent index method and fuzzy mathematics method, the risk assessment results of both methods are moderate. It shows that the two methods are consistent in the evaluation results.
【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U456.3;U231.3

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