隧道衬砌质量的地质雷达检测和数值模拟分析

发布时间：2018-08-16 17:54

【摘要】：由于隧道施工的隐蔽性和施工过程的复杂性,隧道衬砌易在不同程度上存在着质量问题,不可避免地影响围岩应力和变形,甚至影响隧道的运营安全。因此为保证隧道的运营安全,就必须对衬砌进行全面的质量检测,并对衬砌缺陷可能造成的影响进行分析。本文首先运用地质雷达无损检测的原理并结合检测图像对上官隧道的衬砌质量进行了评价,表明隧道衬砌基本无质量缺陷。再基于离散元法以上官隧道为工程背景建立了数值计算模型,对一般的公路隧道施工后衬砌可能存在的主要缺陷进行了模拟计算,分析了围岩应力和变形,并分别与设计情况下的围岩应力和变形进行了对比。分析表明:(1)若存在二衬混凝土厚度比设计厚度小5 cm或锚杆纵向间距最大为1.3 m的缺陷时,则对围岩应力和变形的影响均较小。(2)若存在初支混凝土厚度比设计厚度小5 cm或上台阶断面初支与围岩间局部存在5 cm厚空洞时,虽围岩最大位移仍小于位移收敛警戒值,但对围岩应力产生了很大影响,需及时进行施工处理。(3)在比设计厚度小5 cm的相同情况下,初支混凝土厚度缺陷对围岩应力和变形的影响要远大于二衬混凝土厚度缺陷的影响。(4)上台阶断面初支与围岩间局部存在5 cm厚空洞对围岩应力和变形的影响要大于初支混凝土厚度缺陷(比设计厚度小5 cm)的影响。
[Abstract]:Due to the concealment of tunnel construction and the complexity of construction process, tunnel lining is easy to have quality problems in varying degrees, which inevitably affects the stress and deformation of surrounding rock, and even affects the safety of tunnel operation. Therefore, in order to ensure the safety of tunnel operation, it is necessary to carry out a comprehensive quality inspection of the lining and analyze the possible impact of the lining defects. In this paper, the quality of the lining of Shangguan tunnel is evaluated by using the principle of non-destructive testing of the ground penetrating radar and the image of the inspection, which shows that the lining of the tunnel has no quality defects. Then based on the discrete element method, the numerical calculation model of Shangguan tunnel is established, and the main defects of the lining after construction are simulated and calculated, and the stress and deformation of surrounding rock are analyzed. The stress and deformation of surrounding rock are compared with the design. The results show that: (1) if the thickness of the second lining concrete is 5 cm smaller than the designed thickness or the maximum longitudinal spacing of the anchor rod is 1.3 m, (2) the maximum displacement of surrounding rock is still less than the warning value of displacement convergence, if there are 5 cm thick cavities between the initial supporting concrete thickness and the designed thickness or between the initial branch of the upper step section and the surrounding rock, the maximum displacement of the surrounding rock is still smaller than the warning value of displacement convergence. But it has a great influence on the stress of surrounding rock and needs to be treated in time. (3) under the same condition of 5 cm less than the designed thickness, The influence of thickness defect of initial support concrete on the stress and deformation of surrounding rock is much greater than that on the thickness defect of second lining concrete. (4) the influence of local thick hole of 5 cm thick hole on the stress and deformation of surrounding rock is greater than that of the thickness defect of second lining concrete. The effect of the thickness defect (5 cm less than the designed thickness) of the first supported concrete.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.91;U456.3

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