考虑断层错动空间变异性的水下盾构隧道地层变形特征研究  

Characterizing ground deformation in subaquatic shield tunnels while accounting for spatial variability in fault dislocation

作　　者：黄娟[1] 郑艳林 郑红亮 贾朝军 雷明锋[1] 施成华[1] HUANG Juan;ZHENG Yanlin;ZHENG Hongliang;JIA Chaojun;LEI Mingfeng;SHI Chenghua(School of Civil Engineering,Central South University,Changsha 410075,China;China Railway 12th Bureau Group 7th Engineering Co.,Ltd.,Changsha 410118,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]中铁十二局集团第七工程有限公司,湖南长沙410118

出　　处：《铁道科学与工程学报》2024年第11期4599-4611,共13页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(52378421)。

摘　　要：水下盾构隧道穿越断层错动极易导致地层变形过大并引发突涌水破坏。由于断层错动的力学性质和水力参数难以确定,因此准确预测水下盾构隧道施工引起的地层变形具有实际意义。在确定性条件下,开展考虑断层错动空间变异性的地层变形特征研究,并深入分析断层错动参数变化对地表变形的影响。首先,采用基于高斯型自相关函数和Karhunen-Loève级数展开法的随机场理论,建立不确定性分析数值模型。然后,探讨断层错动黏聚力、弹性模量、渗透系数等参数的空间变异性,以及内摩擦角的变异系数和自相关距离对盾构隧道施工地表变形的影响。最后,利用概率统计方法,研究拱顶沉降和地表最大沉降超过控制阈值的可能性。研究结果表明,在盾构施工过程中,断层错动两侧的地层发生相对剪切错动,导致地表最大沉降量增加。在断层错动参数中,内摩擦角对地表沉降的影响较大,而渗透系数的影响较小。相比确定性分析,考虑断层错动变异性在分析盾构施工地层变形时具有更好的适用性。内摩擦角的变异性对地表变形曲线的离散程度和变形范围影响最为显著,其次是黏聚力和弹性模量,而渗透系数的影响最小。变异系数和自相关距离对变形曲线的离散程度和变形波动量有较大影响。研究结果可为隧道穿越断层错动区域前预警最大沉降值提供重要参考。Underwater shield tunneling adjacent to fault dislocation significantly risks inducing ground deformation and surge water damage.Determining the mechanical and hydraulic properties of fault dislocation is complex,underscoring the need for precise predictions of ground deformation due to tunnel construction.This study examined the effect of fault dislocation on surface deformation under deterministic scenarios,and offered an in-depth analysis of how changes in fault dislocation parameters influence surface deformation.Concurrently,a numerical model for uncertainty analysis was formulated,incorporating random field theory with Gaussian autocorrelation functions and the Karhunen-Loève expansion technique.The research investigated the spatial variability of fault dislocation coefficient of cohesion,elastic modulus,and permeability coefficient—alongside the variability in the internal friction angle and autocorrelation distance,and their impact on the deformation occurring during shield tunneling.Results demonstrate that shear misalignment across fault dislocation zones increases maximum ground surface settlement.The internal friction angle significantly affects surface settlement,while the permeability coefficient has a minimal impact.Accounting for the variability in fault dislocation yields a more applicable method for analyzing ground deformation during shield construction compared to deterministic analysis.Specifically,the internal friction angle’s variability exerts the greatest influence on the dispersion of surface deformation curves and the extent of deformation.This is followed by cohesion and elastic modulus,with permeability coefficient having the least effect.The degree of curve dispersion and deformation fluctuation is notably impacted by the coefficient of variation and autocorrelation distance.Probabilistic methods are used to evaluate the likelihood of exceeding safety thresholds for arch settlement and maximum surface settlement.The study can provide vital insights for early warning systems to a

关 键 词：隧道工程 断层错动 流固耦合 随机场理论 地表变形 

分 类 号：U45[建筑科学—桥梁与隧道工程]