穿江盾构隧道管片结构力学响应及施工控制技术研究

发布时间：2018-09-15 19:04

【摘要】：近年来,我国基础设施建设步伐不断加快,越来越多的隧道建设工程采用盾构法施工,尤其是水下隧道工程。然而,在盾构隧道施工过程中,管片结构经常出现上浮、错台、开裂现象。本文在国内外有关研究现状的基础上,以衡阳市合江套湘江隧道工程为背景,采用MIDAS-GTS NX软件对盾构施工阶段建模分析,研究施工荷载作用下管片衬砌结构的力学响应规律。并对在管片结构上浮、错台、开裂现象进行机理分析,总结其引发因素,提出相应控制对策。全文主要研究内容及成果如下:(1)通过MIDAS-GTS NX软件进行建模,研究施工荷载作用下管片衬砌结构的力学响应。随着注浆压力的增加,衬砌管片产生的水平和竖向位移均相应增加。随着千斤顶推力的增加,管片的水平和竖向位移均会增加,但不明显。管片衬砌环拱顶和拱底产生了较大的挤压变形,拱腰处也有相应的水平变形;压应力最大处均位于拱腰位置。(2)对管片结构上浮现象进行机理分析,通过监测数据总结了管片上浮规律:随着时间增加,浆液的黏滞阻力不断增大,上浮速度逐渐减少;管片衬砌环上浮的大部分位移均在浆液初凝时间以内完成;在初凝后的一段时间内,上浮量值幅度较小,最终上浮量趋于稳定值。(3)对管片结构错台机理进行分析,总结了管片结构错台的引发因素。推导出了注浆过程中单一管片错台量的计算公式。单一管片错台公式表明:(1)注浆压力越大,单一管片错台量越大;(2)螺栓弯曲刚度较大的管片,产生较小的错台量。(3)螺栓与螺栓孔之间的间隙越大时,发生错台的管片对应的错台量就越大。由此,预先确定错台量的大小,对控制管片错台现象具有重要的实践意义。
[Abstract]:In recent years, the pace of infrastructure construction in China has been speeding up. More and more tunnel construction projects use shield method, especially underwater tunnel construction. However, in the shield tunnel construction process, segment structure often appears floating, staggered, cracking phenomenon. On the basis of the domestic and foreign research status, taking the Heijiang Suaxiang River Tunnel Project in Hengyang City as the background, this paper uses the MIDAS-GTS NX software to model and analyze the shield construction stage, and studies the mechanical response law of the segment lining structure under the construction load. The mechanism of floatation, stagger and cracking in segment structure is analyzed, and the initiation factors are summarized, and the corresponding control measures are put forward. The main research contents and results are as follows: (1) the mechanical response of segment lining structure under construction load is studied by modeling with MIDAS-GTS NX software. With the increase of grouting pressure, the horizontal and vertical displacement of lining segment increases accordingly. With the increase of Jack thrust, the horizontal and vertical displacement of the segment will increase, but not obvious. The segment lining ring arch roof and bottom produced the big extrusion deformation, the arch waist also has the corresponding horizontal deformation, the maximum compressive stress is located in the arch waist position. (2) the mechanism analysis of the floating phenomenon of the segment structure is carried out. According to the monitoring data, the floating law of the segment is summarized: with the increase of time, the viscosity resistance of the slurry increases and the floating velocity decreases gradually, and most of the displacements of the segment lining ring are completed within the initial setting time of the slurry; Within a period of time after initial setting, the amplitude of floating value is small, and finally the floatation value tends to be stable. (3) the mechanism of segment structure stagger is analyzed, and the initiation factors of segment structure fault table are summarized. A formula for calculating the stagger of a single segment during grouting is derived. The single segment stagger formula shows: (1) the greater the grouting pressure, the greater the single segment stagger; (2) the larger the bending stiffness of the bolt, the smaller the stagger. (3) the larger the gap between the bolt and the bolt hole, The greater the number of staggered segments corresponding to the occurrence of the stagger. Therefore, it is of great practical significance to determine the amount of stagger in advance to control the stagger phenomenon of segment.
【学位授予单位】：湖南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U455.43

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