Effect of Jack Thrust Angle Change on Mechanical Characteristics of Shield Tunnel Segmental Linings Considering Additional Constrained Boundaries
Effect of Jack Thrust Angle Change on Mechanical Characteristics of Shield Tunnel Segmental Linings Considering Additional Constrained Boundaries
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DOI：
10.3390/app12104855
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发表时间：
2022-05
期刊：
影响因子：
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通讯作者：
Lichao He;Y. Jiang;Wenjun Zhang
中科院分区：
文献类型：
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作者：
Lichao He;Y. Jiang;Wenjun Zhang
随着盾构机姿态的调整，千斤顶的推力角会发生变化，可能对管片衬砌结构造成较大的破坏。考虑各种施工荷载形成的附加约束边界，本文提出了三维精细有限元方法，研究千斤顶推力角变化对盾构隧道力学特性的作用机理和影响。首先，建立了有限元方法并进行了验证。在此基础上，对某隧道十一环衬砌在不同千斤顶推力角条件下的力学性能进行了分析。对所得的位移、变形和应力分布进行了深入的讨论。最后给出了千斤顶推力角控制的定量标准。结果表明，最大管片位移发生在盾尾外第二圈拱腰下部，与姿态调整关系不大。随着千斤顶推力角的增大，环间最大偏移量呈线性增大，不利于衬砌结构的安全。隧道位移的发展方向与千斤顶推力挠度的发展方向相反。盾构上行时，千斤顶推力偏转对隧道位移影响最大，也是对管片衬砌最不利的情况。本文的研究结果为分析千斤顶推力对盾构隧道的影响提供了新的思路。
With the attitude adjustment of shield machine, the jack thrust angle will change and may lead to great damage to segmental lining structures. In this paper, a three-dimensional refined finite element method is proposed to study the action mechanism and influence of jack thrust angle change on the mechanical characteristics of shield tunnel, considering additional constrained boundaries formed by various construction loads. Firstly, the finite element method is established and verified. Then, a series of analyses is carried out to investigate the mechanical performance of a certain tunnel lining with eleven rings under conditions of different jack thrust angles. An in-depth discussion is conducted on the obtained displacement, deformation, and stress distribution. A quantitative standard is finally gained for controlling the jack thrust angle. The results show that the maximum segment displacement occurs at the lower part of the arch waist of the second ring out of the shield tail, which has little relationship with the attitude adjustment. With the increase of the jack thrust angle, the maximum offset between the rings increases linearly, which is not conducive to the safety of the lining structures. The development direction of the tunnel displacement is opposite to that of the jack thrust deflection. The displacement of the tunnel is most affected by the jack thrust deflection when the shield machine is upward, which is also the most unfavorable situation for the segmental linings. The results in this paper provide novel insights into the effect of jack thrust on shield tunnel.