考虑氯盐侵蚀劣化作用的盾构隧道结构抗震性能研究

发布时间：2018-10-16 14:15

【摘要】：随着城市交通隧道的不断发展,越来越多的水下交通隧道工程正在开展,我国沿海地区处于环太平洋地震带,水下交通隧道不可避免的会穿越这些地区,水下盾构隧道受到复杂地质环境、高水压、侵蚀环境等因素的影响,隧道结构在侵蚀环境中发生劣化后的抗震性能更是无法估计,因此,侵蚀环境和地震荷载共同影响下的隧道结构安全和稳定性评价十分必要。本文依托厦门地铁2号线过海段工程,对荷载和侵蚀共同作用下的隧道结构进行了抗震性能分析,得到了如下主要研究成果:(1)介绍了隧道结构耐久性的影响因素,其中水土荷载和氯离子侵蚀是水下盾构隧道结构性能劣化的主要因素,分析了水下盾构隧道在荷载和氯离子侵蚀作用下的劣化机理。(2)基于现有的荷载和氯离子侵蚀作用下管片劣化本构模型,依托厦门地铁过海段工程,对劣化隧道结构在地震作用下的响应进行了分析。(3)结合现有隧道结构性能水平划分方式,初步提出适用于圆形盾构隧道的性能水平量化指标,并根据已有管片钢筋锈蚀率计算公式,建立管片不同钢筋锈蚀率区间与其抗震性能的对应关系。(4)根据结构容许应力和损伤程度,初步给出了适用于圆形盾构隧道各性能水平的量化指标限值,并对管片不同钢筋锈蚀率区间对应的结构性能水平进行确定。
[Abstract]:With the continuous development of urban traffic tunnels, more and more underwater traffic tunnel projects are being carried out. The coastal areas of our country are located in the seismic belt around the Pacific Ocean, and the underwater traffic tunnels will inevitably cross these areas. The underwater shield tunnel is affected by complex geological environment, high water pressure, erosion environment and so on. The seismic performance of tunnel structure after deterioration in the erosion environment is even more difficult to estimate. It is necessary to evaluate the safety and stability of tunnel structure under the influence of erosion environment and seismic load. In this paper, based on the Xiamen Metro Line 2 cross sea section project, the seismic performance of the tunnel structure under the combined action of load and erosion is analyzed. The main research results are as follows: (1) the factors affecting the durability of the tunnel structure are introduced. Among them, soil and water load and chloride erosion are the main factors of structural deterioration of underwater shield tunnel. The degradation mechanism of underwater shield tunnel under load and chloride ion erosion is analyzed. (2) based on the existing constitutive model of segment deterioration under the action of load and chloride ion erosion, Xiamen subway cross sea section project is relied on. The response of the degraded tunnel structure under earthquake action is analyzed. (3) combined with the existing ways of dividing the tunnel structure performance level, the performance level quantification index suitable for circular shield tunnel is put forward preliminarily. According to the formula of corrosion rate of steel bar, the relationship between corrosion rate and seismic performance of steel bar is established. (4) according to the allowable stress and damage degree of the structure, The quantitative index limits applicable to each performance level of circular shield tunneling are preliminarily given, and the structural performance levels corresponding to different sections of steel bar corrosion rate are determined.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U455.43

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