衬砌钢筋锈蚀对岩石隧道稳定性影响规律研究

发布时间：2018-06-05 04:03

本文选题：隧道衬砌 + 钢筋锈蚀　；参考：《中国矿业大学》2015年硕士论文

【摘要】：隧道工程在世界范围内,特别是现今的中国得到了极大发展,但是越来越多的衬砌病害问题影响着隧道工程的正常使用。钢筋锈蚀是引起钢筋混凝土结构病害的主要原因。如果衬砌钢筋过早的发生锈蚀,其维护不仅耗费大量的人力物力,还影响隧道的正常运营,缩短使用寿命,严重时还会给隧道内车辆的行驶带来安全问题。开展不同锈蚀条件下混凝土劣化对衬砌结构稳定性影响的研究,对隧道的健康评价具有十分重要的意义。本文以此为主线,采用理论分析、物理试验和数值模拟多种手段研究衬砌钢筋锈蚀问题。数值模拟过程中通过将钢筋锈蚀问题转化为相应混凝土力学性能退化的问题,对钢筋锈蚀引起混凝土劣化作用下的衬砌结构应力和变形规律进行研究,分析各因素的影响程度并判断结构的稳定性。取得地主要研究结果如下:(1)通过实验室物理试验得到了钢筋在氯化氢溶液、氯化钠溶液和纯净水中的平均年腐蚀深度值。(2)拱顶和直墙部位钢筋锈蚀加大了结构的变形,但对最大应力无影响。拱肩和墙脚部位钢筋锈蚀使得钢筋锈蚀处应力减小,而周围应力增大,衬砌内侧应力变化明显。结构中最大拉应力和位移值随着锈蚀作用的增加而逐渐增大,安全系数值逐渐降低。(3)各位置在不同范围锈蚀作用下,轴向增大对衬砌应力的影响大于环向。不同位置出现锈蚀,混凝土劣化单元处围岩的位移值基本不变,应力值变化较小,衬砌轻度锈蚀对围岩稳定性影响不大。(4)墙脚是衬砌结构钢筋发生锈蚀后最容易出现问题的危险位置,其次是拱肩,直墙。锈蚀程度是三因素中对衬砌结构稳定性最不利的因素。(5)在实际工程中,可根据隧道衬砌主要位置的锈蚀深度、锈蚀程度和锈蚀范围得到钢筋锈蚀率并计算劣化后的混凝土抗拉强度,对隧道结构稳定性作出评价。
[Abstract]:Tunnel engineering has been greatly developed in the world, especially in China, but more and more lining problems affect the normal use of tunnel engineering. The corrosion of steel bar is the main cause of the disease of reinforced concrete structure. If the lining steel bar rusts prematurely, its maintenance not only consumes a lot of manpower and material resources, but also affects the normal operation of the tunnel, shortens the service life, and brings safety problems to the driving of the vehicle in the tunnel seriously. It is very important to study the influence of concrete deterioration on the stability of lining structure under different corrosion conditions. In this paper, the corrosion problem of lining steel bar is studied by means of theoretical analysis, physical test and numerical simulation. In the process of numerical simulation, the stress and deformation law of lining structure caused by reinforcement corrosion is studied by transforming the problem of reinforcement corrosion into the degradation of corresponding concrete mechanical properties. Analyze the influence degree of each factor and judge the stability of structure. The main results obtained are as follows: (1) the average annual corrosion depth of steel bars in hydrogen chloride solution, sodium chloride solution and purified water is obtained by physical experiments in laboratory. But it has no effect on the maximum stress. The corrosion of steel bar at the arch shoulder and the foot of the wall makes the stress of the corroded steel bar decrease, while the stress around the wall increases, and the stress inside the lining changes obviously. The maximum tensile stress and displacement increase with the increase of corrosion, and the safety factor decreases gradually. Corrosion occurs in different locations, the displacement of surrounding rock at the deterioration unit of concrete is basically unchanged, and the stress value changes slightly. The slight corrosion of lining has little effect on the stability of surrounding rock. The foot of wall is the dangerous position where the corrosion of steel bar of lining structure occurs most easily, followed by arched shoulder and straight wall. Corrosion degree is the most disadvantageous factor of three factors to the stability of lining structure. In actual engineering, it can be based on the corrosion depth of the main position of tunnel lining. The corrosion degree and corrosion range of the steel bar are obtained and the tensile strength of the degraded concrete is calculated, and the stability of the tunnel structure is evaluated.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U451;U457

【参考文献】