破碎富水围岩段隧道渗流影响的研究

发布时间：2018-06-28 03:36

本文选题：破碎富水围岩 + 流固耦合　；参考：《兰州交通大学》2017年硕士论文

【摘要】：随着公路网和铁路网的不断发展,在修建过程中所遇到需要修建隧道通过的路段也不断增加,而其中破碎富水围岩段隧道也变得越来越常见。所以研究在破碎富水围岩段隧道的施工具有重大的实际意义。本文首先对富水隧道渗流的研究意义与研究现状做了总结;之后对扑鸭脚隧道附近的工程地质与水文地质情况做出了概述;然后又对在扑鸭脚隧道YK217+660断面的监测方法进行了介绍,并对监测的结果进行了分析;之后结合现场实际建立了基于FLAC3D的数值计算模型,模拟了隧道的开挖过程,并对渗流耦合和非渗流耦合工况下的隧道施工时的位移与应力进行了比较;最后对半断面注浆和全断面注浆对渗流耦合隧道位移和应力的影响进行了比较,对这两种工况进行了优选。本文的主要结论有:(1)通过应用FLAC3D软件,对渗流耦合计算步增加对隧道位移影响的分析,结合工程实际的施工状况得出了在当前模型条件下,7500个耦合步数是合理的结论。(2)渗流对监测断面附近的位移影响不大,但对开挖掌子面附近的竖向最大位移影响比较大,影响比率在20%左右,而且渗流使得最大位移的范围有所增大,削弱了隧道周围围岩的稳定性。力学分析的结果说明,渗流对隧道监测断面和开挖掌子面附近的竖向最大应力的影响比较大,在30%左右,而对其水平方向的应力的影响则极小,在开挖掌子面附近仅为1.5%左右。(3)半断面注浆对隧道掌子面径向位移几乎没有控制力,对竖向位移的控制力也不强,在10%左右;全断面注浆则对隧道的竖向位移和径向位移有着明显的限制作用,对径向位移有30%左右的影响率,对竖向位移则有25%左右。(4)在对隧道所受应力影响方面,半注浆对隧道竖向应力的影响率为20%要大于全注浆的10%,但全注浆对隧道受到的水平力的影响率为30%要大于半注浆的20%。因为从应力大小而言,水平力为大应力,所以综合而言,从减小应力的角度来讲,全注浆对隧道的保护效果也要好于半注浆。(5)通过综合分析,在渗流特别丰富,隧道位移较大,衬砌极易压坏的情况下建议使用全断面注浆法,而在隧道位移不大,衬砌也不易压坏但是有少量的渗流影响隧道施工与开挖进度的情况下,从经济的角度考虑,半断面注浆就能满足要求。
[Abstract]:Along with the continuous development of highway network and railway network, the sections that need to be built through the tunnel are also increasing in the process of construction, and the tunnels in the fractured water rich surrounding rock are becoming more and more common. Therefore, it is of great practical significance to study the construction of tunnel in the broken water rich surrounding rock section. The significance and current research status are summarized, and then the engineering geology and hydrogeological conditions are summarized, and then the monitoring method of the YK217+660 section is introduced, and the results of the monitoring are analyzed. Then a numerical calculation model based on FLAC3D is set up in combination with the actual field. The excavation process of tunnel is simulated, and the displacement and stress of tunnel under coupled and non seepage flow coupling are compared. Finally, the effect of the half section grouting and full section grouting on the displacement and stress of the coupled tunnel is compared, and the two conditions are optimized. The main conclusions of this paper are: (1) pass. FLAC3D software is used to analyze the influence of the seepage coupling calculation step on the tunnel displacement. According to the actual construction conditions of the engineering, the 7500 coupling steps are reasonable conclusions. (2) the influence of the seepage on the displacement near the monitoring section is not significant, but the vertical maximum displacement near the excavation face is compared. The ratio is about 20%, and the percolation makes the maximum displacement increase, which weakens the stability of the surrounding rock around the tunnel. The results of mechanical analysis show that the influence of seepage on the tunnel monitoring section and the vertical maximum stress near the excavation face is relatively large, at about 30%, and the stress on the horizontal direction is extremely affected. Only about 1.5% near the excavation face. (3) the semi section grouting has little control on the radial displacement of the tunnel face, and the control force of the vertical displacement is not strong, at about 10%. The full section grouting has an obvious limiting effect on the vertical displacement and radial displacement of the tunnel, and the radial displacement has an influence rate of about 30%, and the vertical direction is vertical to the vertical displacement. The displacement is about 25%. (4) in the stress effect on the tunnel, the influence rate of the semi grouting on the vertical stress of the tunnel is 20% greater than that of the full grouting, but the effect rate of the full grouting on the horizontal force of the tunnel is 30% greater than the half grouting 20%. because the horizontal force is large stress in terms of the stress size, so in comprehensive terms, it should be reduced. In terms of force, full grouting has better protective effect on tunnel than half grouting. (5) through comprehensive analysis, full section grouting method is suggested in the case of percolation is especially rich, tunnel displacement is large and the lining is easily crushed, while the tunnel displacement is not large and the lining is not easily crushed, but a small amount of seepage affects tunnel construction and excavation. From the economic point of view, half section grouting can meet the requirements.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U452.11

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