【作者】 崔博；

【导师】 郑俊杰；

【作者基本信息】 华中科技大学 ， 桥梁与隧道工程， 2020， 硕士

【摘要】 随着深埋长隧洞建设量的增加,TBM掘进相关的研究变得越来越重要。本文考虑了岩石峰后力学行为等复杂力学效应,首先对圆隧的围岩变形进行二维分析,进而延展至三维空间对TBM掘进摩阻力及卡机事故进行研究。首先,基于应力分层模型,结合塑性软化系数和Hoek-Brown屈服准则、Mohr-Coulomb屈服准则,改进了应变软化围岩变形的数值求解方法。利用算例和FLAC3D模拟,验证其合理性,并分析了塑性软化系数临界值和岩石剪胀特性对于围岩径向位移的影响。结果表明:相同条件下,利用弹脆塑、应变软化、理想弹塑性力学模型所得围岩变形值依次减小;在软岩中,剪胀特性使得围岩变形增大的规律更加显著。然后,基于隧道收敛约束法的思想,在考虑岩石峰后力学行为的基础上,结合非线性剪胀特性和停机时长,提出了TBM掘进摩阻力计算方法,验证其合理性。并且,总结了一种新的卡机事故预测模型。之后,在考虑超挖间隙的基础上,展开了相关的讨论。结果表明:岩体质量越好,越不易发生卡机事故;对于应变软化围岩而言,卡机事故的判断需要详细计算,不可一概而论。最后,结合GSI岩体分类系统,优化了TBM掘进摩阻力计算方法。根据GSI系统下的Hoek-Brown准则强度参数公式,以应变软化围岩为研究对象,分析了五类因素对TBM掘进摩阻力的影响。结果表明:在护盾相关参数分析方面,仅护盾长度对其影响明显;随着超挖间隙增大,摩阻力先迅速减小,后减速放缓;在停机初期摩阻力增加较大,而后期其值基本不变。更多还原

【Abstract】 With the increase in the construction of deep long circular tunnels,the research related to the TBM advancing technology becomes more significant gradually.Based on the mechanical behavior of the rock after the peak,this dissertation studies the rock deformation of the circular tunnel by the two-dimensional analysis.Afterthat,the theory is extended to the three-dimensional space for investigating TBM tunneling friction resistance and the jamming accident.Firstly,based on the stress stratified model,combined with the critical value of the plastic softening coefficient,the Hoek-Brown yield criterion,and the Mohr-Coulomb yield criterion,a numerical solution for the strain-softened surrounding rock deformation of circular tunnel is obtained.Its rationality is verified by a calculation example and FLAC3 D numerical simulation.The influence of the critical value of plastic softening coefficient and rock mass dilatancy characteristic on the radial displacement of surrounding rock was analyzed.The results show that under the same conditions,the deformation values obtained using the elastic-brittle-plastic,strain-softening,and elastic-perfectly-plastic models decrease in order,and the strain softening model is a unified model;in soft rock,the dilatancy characteristic makes the deformation of the surrounding rock increasing more significantly.Secondly,based on the confined convergence method,considering the post-peak mechanical behavior of rock,combined with the non-linear dilatancy characteristic and the downtime,a theoretical solution of TBM driving friction resistance was proposed,and its rationality is verified.In addition,a new model for predicting TBM jamming accident is summarized.Then,taking the over-excavation gap into consideration,relevant discussions are carried out.The results show that the better the quality of the rock mass is,the less prone the jamming disaster is;for strain-softened surrounding rocks,the judgment of the jamming disaster requires detailed calculation and cannot be generalized.Finally,combined with the GSI rock mass classification system,the calculation method of the TBM driving friction resistance is optimized.According to the strength parameter formulas of the Hoek-Brown criterion under the GSI system,and taking the strain-softened surrounding rock into consideration,the influence of five factors on the friction resistance of the TBM is analyzed.The results show that: in terms of the analysis of shield-related parameters,only the shield length has significant effect on the friction resistance;the larger the over-excavation is,the frictional resistance decreases rapidly at first,and then reduce slightly;the frictional resistance increases at the beginning of the shutdown,and the value keeps constant after that.更多还原