软岩隧道台阶法施工变形控制措施研究

发布时间：2018-07-29 20:17

【摘要】：在我国大规模的隧道施工建设中,软弱围岩隧道的大变形问题一直困扰着诸多隧道建设者。究其原因主要是对软弱围岩隧道的变形特征、变形机理和变形控制措等方面的研究存在诸多认识上的不足。针对这一系列的问题,本文以牡绥线双丰隧道为工程依托,以软弱围岩隧道变形为背景,理论分析分析软弱围岩隧道的变形机理。其次由实际监控量测分析提出不同的变形控制措施并结合数值模拟优选出最佳的变形控制措施。最后运用突变理论分析双丰隧道极限位移,并依据结果及工程界普遍使用的三级管理机制建立双丰隧道的变形控制基准,并将变形控制措施的理论分析与数值模拟的优选结果相结合,归纳总结双丰隧道的合理变形控制措施。论文主要工作和成果如下:(1)理论分析了软岩的变形机理,主要包括:软岩的概念;软岩的分类;软岩的力学特征;软岩的变形破坏特征。(2)通过现场实际监控量测数据对双丰隧道的变形和支护结构受力进行分析。数据分析表明,围岩初期变形较大且持续时间较长;岩体侧向压力较大,使得支护结构受力呈现不对称性。(3)依据软岩的变形机理和实际监控量测分析,提出有针对性的变形控制措施,并通过数值模拟对不同的变形控制措施进行对比分析,主要包括:采用不同台阶高度、不同台阶长度、不同开挖进尺、不同锁脚锚管以及不同纵向连接形式等。得出优选结果,宜采用3.4m台阶高度、5m台阶长度、0.5m开挖进尺、上台阶采用下斜角度较大的锁脚锚管、中下台阶采用下斜角度较小的锁脚锚管、纵向连接则采用14号槽钢。(4)运用突变理论分析双丰隧道极限位移,并依据结果及工程界普遍使用的三级管理机制建立双丰隧道的变形控制基准。(5)通过将变形控制措施的理论分析与数值模拟的优选结果相结合,归纳总结双丰隧道的合理变形控制措施,包括:施工方法——建议采用三台阶七步开挖法;支护方法——初期支护为锚喷支护,同时辅助锁脚锚管以及纵向连接。
[Abstract]:In the large-scale tunnel construction in China, the problem of large deformation of soft surrounding rock tunnel has been puzzling many tunnel builders. The main reason is that the research on deformation characteristics, deformation mechanism and deformation control measures of soft surrounding rock tunnel has many shortcomings. In view of this series of problems, this paper takes Shuangfeng tunnel of Musui line as the engineering backing, takes the deformation of soft surrounding rock tunnel as the background, and theoretically analyzes the deformation mechanism of soft surrounding rock tunnel. Secondly, different deformation control measures are put forward based on the analysis of actual monitoring measurements, and the best deformation control measures are selected in combination with numerical simulation. Finally, the limit displacement of Shuangfeng tunnel is analyzed by catastrophe theory, and the deformation control benchmark of Shuangfeng tunnel is established according to the results and the three-level management mechanism commonly used in engineering field. Combining the theoretical analysis of deformation control measures with the optimal selection results of numerical simulation, the reasonable deformation control measures for Shuangfeng Tunnel are summarized. The main work and achievements are as follows: (1) the deformation mechanism of soft rock is analyzed theoretically, including: the concept of soft rock, the classification of soft rock, the mechanical characteristics of soft rock; The deformation and failure characteristics of soft rock. (2) the deformation of Shuangfeng tunnel and the force of supporting structure are analyzed by the actual monitoring data. The data analysis shows that the initial deformation of surrounding rock is large and the duration is long, and the lateral pressure of rock mass is large, which makes the supporting structure appear asymmetry. (3) according to the deformation mechanism of soft rock and the actual monitoring measurement analysis, The corresponding deformation control measures are put forward, and different deformation control measures are compared and analyzed by numerical simulation, which mainly include: adopting different step height, different step length, different excavation advance, Different locking foot anchor pipe and different longitudinal connection forms. The optimum selection results are as follows: 3. 4 m step height and 5 m step length and 0.5 m excavation advance, the upper step adopts lock foot anchor pipe with large downslope angle, and the middle and lower step adopts lock foot anchor pipe with lower angle. In longitudinal connection, 14 channel steel is adopted. (4) the limit displacement of Shuangfeng Tunnel is analyzed by catastrophe theory. Based on the results and the three-level management mechanism commonly used in engineering, the deformation control datum of Shuangfeng tunnel is established. (5) by combining the theoretical analysis of deformation control measures with the optimal selection results of numerical simulation, The reasonable deformation control measures of Shuangfeng Tunnel are summarized, including: construction method-three steps and seven steps excavation method; support method-initial support is bolting and shotcrete support, at the same time auxiliary locking foot bolting pipe and longitudinal connection.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.4

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