基于短梁-弹簧模型的盾构隧道施工期上浮变形计算方法  

Calculation of uplift deformation during shield tunnel excavation based on a short beam-spring model

作　　者：李文博 甘晓露 刘念武[1] 吴昊 谌珊珊 LI Wen-bo;GAN Xiao-lu;LIU Nian-wu;WU Hao;SHEN Shan-shan(School of Civil Engineering and Architecture,Zhejiang Sci-Tech University,Hangzhou,Zhejiang 310018,China)

机构地区：[1]浙江理工大学建筑工程学院,浙江杭州310018

出　　处：《岩土力学》2024年第12期3755-3767,共13页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.52078466);浙江省自然科学基金(No.LQ24E080008)。

摘　　要：盾构隧道在掘进过程中易出现管片上浮问题,为更加真实地描述施工期盾构隧道在上浮力作用下产生的管片环间错台变形和张开变形,提出基于短梁-弹簧模型的盾构隧道上浮变形理论计算方法。首先,引入Euler-Bernoulli短梁和环间接头弹簧模拟盾构隧道纵向结构,通过设置边界弹簧考虑盾构机盾尾对管片的任意约束作用;之后,采用有限差分理论推导得到施工期上浮力作用下盾构隧道上浮变形解答;最后,对比实际工程案例和数值模型结果以及传统等效梁计算结果验证了计算方法的正确性和有效性,并探明了理论计算模型中关键参数的敏感性,进一步讨论了浆液未凝固段长度、管片环间接头弹簧刚度以及地基弹性模量对隧道上浮变形规律的影响。研究结果表明:与传统连续梁模型结果相比,新方法可以真实地反映盾构隧道的非连续性变形性状,定量分析管片环环间的错台变形和张开变形;通过参数分析可知,浆液未凝固段长度的增长会明显增大盾构隧道上浮变形最大值和变形影响范围;适当提高环间接头的剪切刚度和转动刚度可以有效降低隧道上浮位移、管片环间错台变形和张开变形;在地基弹性模量较小的软弱地层中盾构隧道施工期的上浮变形更不易控制。Tunnel lining uplift frequently arises during shield tunneling excavation.To accurately characterize the dislocation between adjacent rings and joint openings induced by uplift pressure during shield tunneling,we propose a theoretical calculation method for uplift deformation of shield tunnels based on the short beam-spring model.Initially,we establish Euler-Bernoulli short beams and joint springs to simulate the longitudinal structure of shield tunnels,considering the arbitrary restraining effect of the shield tail through boundary springs.Subsequently,we apply the finite difference theory to derive the uplift deformation of shield tunnels under uplift forces during tunneling.Ultimately,we validate the correctness and effectiveness of the method through comparisons with engineering cases,numerical modeling results,and traditional equivalent beam calculations.We discuss the sensitivities of key parameters,analyzing the influence of the unconsolidated zone length,circumferential joint stiffness,and modulus of elasticity on the deformation pattern of tunnel uplift.The results indicate that,compared to conventional continuous beam models,our calculation method accurately reflects discontinuous deformation characteristics and reasonably captures the dislocation between adjacent rings and joint openings.Analysis of related parameters reveals that increasing the length of the unconsolidated zone significantly enhances both the maximum uplift deformation and its range of influence.Appropriately increasing the shear and rotational stiffness of circumferential joints can mitigate uplift displacement and reduce dislocation between adjacent rings and joint openings.The uplift deformation of shield tunnels in weak strata with low modulus of elasticity is more difficult to control.

关 键 词：盾构隧道 管片上浮 环间接头 理论计算 有限差分法 

分 类 号：TU454[建筑科学—岩土工程]