双护盾TBM开挖隧道围岩稳定性研究

发布时间：2018-06-27 14:19

本文选题：双护盾TBM + 围岩稳定性　；参考：《西南交通大学》2017年硕士论文

【摘要】：与传统的隧道开挖方法相比,双护盾TBM法施工对隧道围岩的扰动小,能够有效的维护围岩的自稳能力,因此在隧道设计和施工阶段可以有效利用围岩的自稳强度,降低支护结构的设计参数,节约工程材料,也能保证施工的安全、高质。然而使用TBM开挖隧道,主要面临的问题是隧道围岩稳定性能否确保TBM正常掘进,避免出现卡机、埋机等事故。现有的围岩分级方法大多是针对新奥法、钻爆法等来评判隧道围岩质量,而针对采用双护盾TBM法开挖的隧道围岩质量评价方法的研究较少,也不成熟。由于采用双护盾TBM法施工导致隧道围岩被机械和管片隔离,施工人员不能直观的获取隧道围岩的地质情况,因此传统的围岩分级方法在双护盾TBM法施工中并不适用。本文在现有围岩分级基础上,选取双护盾TBM掘进参数、碴料参数作为隧道围岩分级指标,基于熵权法理论计算得到TBM推力、刀具贯入度、TBM扭矩、片状岩碴含量、块状岩碴含量、粉状岩碴含量六个指标的权重值分别为0.106、0.273、0.074、0.060、0.358、0.129,建立对***隧道工程围岩分级方法,以此来判定刀盘前方岩体情况,并结合实际开挖隧道围岩等级进行验证,通过熵权法理论计算得到的围岩分级结果与实际工程中围岩等级结果相同。因此基于熵权法理论可以对隧道围岩分级,在掘进机开挖岩体的过程中,能够快速、准确了解正在开挖岩体的质量情况,进而根据岩体的质量等级来指导隧道施工,及时调整安装管片的型号。***隧道是一个深埋隧道,双护盾TBM面临的最大问题是围岩的大变形,若隧道围岩变形较大,会挤压护盾,阻碍掘进机前行,最终导致卡机。研究隧道围岩变形情况,结合隧道围岩变形控制基准值,判断围岩的稳定性,做好超前支护措施,保证双护盾TBM顺利掘进通过。故本文通过FLAC3D软件模拟卡机事故段围岩变形情况,得到隧道呈现四周整体向洞内收敛的特点,隧道掌子面的空间效应对附近围岩的变形影响显著。当双护盾TBM不断向前掘进,掌子面前移,使得掌子面附近的隧道围岩变形产生较大变化,并远大于围岩的最初变形。模拟得到支护状态下机械护盾区域拱顶围岩最大下沉可达134.87mm,远大于预留量,使得洞周围岩挤压机械护盾,阻碍掘进机向前推进。因此研究围岩变形规律来指导双护盾TBM施工有着重要意义。
[Abstract]:Compared with the traditional tunnel excavation method, the double shield TBM method has small disturbance to the surrounding rock of the tunnel, and can effectively maintain the stability of the surrounding rock. Therefore, the self stability strength of the surrounding rock can be effectively used in the design and construction stage of the tunnel, the design parameters of the supporting structure can be reduced, the engineering materials are saved, and the safety and quality of the construction can be ensured. The main problem is whether the stability of the surrounding rock can ensure the normal driving of the TBM, and avoid the accident of the accident. The existing surrounding rock classification methods are mostly based on the new Austrian method, drilling and blasting method and so on to judge the quality of the surrounding rock of the tunnel, and the quality evaluation method of the tunnel surrounding the tunnel by the double shield TBM method is studied. Since the construction of the tunnel surrounding rock is isolated by the mechanical and segment of the tunnel, the construction personnel can not directly obtain the geological conditions of the tunnel surrounding rock, so the traditional classification method of the surrounding rock is not suitable for the construction of the double shield TBM method. On the basis of the existing surrounding rock classification, this paper selects the double shield TBM driving parameter on the basis of the existing surrounding rock classification. According to the entropy weight method, the TBM thrust, the penetration degree of the tool, the TBM torque, the piece like rock ballast content, the massive rock ballast content, and the weight of the powdery rock ballast are 0.106,0.273,0.074,0.060,0.358,0.129 respectively, based on the entropy weight method, and the classification method of the surrounding rock of the tunnel project is established to determine the classification of the surrounding rock of the tunnel project. The rock mass in front of the cutter plate is verified by the actual excavation of the surrounding rock of the tunnel. The result of the classification of the surrounding rock obtained by the entropy weight method is the same as that in the actual project. Therefore, the entropy weight method can be used to classify the surrounding rock of the tunnel, and it can be quickly and accurately understood in the process of excavation of the rock mass. The quality of rock mass is excavated to guide the tunnel construction according to the quality grade of rock mass. The tunnel is a deep buried tunnel. The biggest problem of the double shield TBM is the large deformation of the surrounding rock. If the deformation of the tunnel surrounding rock is large, the shield will be extruded and the driving machine is hindered. The deformation of the surrounding rock, combined with the control datum of the deformation control of the tunnel surrounding rock, determines the stability of the surrounding rock, and completes the advance support measures to ensure the smooth driving of the double shield TBM. Therefore, this paper simulated the deformation of the surrounding rock of the accident section by FLAC3D software, and obtained the characteristics of the tunnel convergence to the tunnel, and the space effect of the tunnel face. The deformation of surrounding rock is significantly affected. When the double shield TBM is heading forward and the palm is moved in front of the palm, the deformation of the tunnel surrounding the tunnel is greatly changed and is far larger than the initial deformation of the surrounding rock. The maximum subsidence of the surrounding rock of the vault in the mechanical shield area under the support condition is up to 134.87mm, which is far greater than the reserve. The surrounding rock is extruded by mechanical shield, which hinders the roadheader advancing. Therefore, it is very important to study the deformation law of surrounding rock to guide the construction of double shield TBM.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U451.2

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