廖伯富, 黄明, 路遥, 等. 2023. 非均质断层破碎带盾构开挖面极限支护力上限解[J]. 工程地质学报, 31(6): 2008-2019. doi: 10.13544/j.cnki.jeg.2021-0537.
    引用本文: 廖伯富, 黄明, 路遥, 等. 2023. 非均质断层破碎带盾构开挖面极限支护力上限解[J]. 工程地质学报, 31(6): 2008-2019. doi: 10.13544/j.cnki.jeg.2021-0537.
    Liao Bofu, Huang Ming, Lu Yao, et al. 2023. Upper bound solution of shield tunnel face supporting pressure in non-homogeneous fault fracture zone[J]. Journal of Engineering Geology, 31(6): 2008-2019. doi: 10.13544/j.cnki.jeg.2021-0537.
    Citation: Liao Bofu, Huang Ming, Lu Yao, et al. 2023. Upper bound solution of shield tunnel face supporting pressure in non-homogeneous fault fracture zone[J]. Journal of Engineering Geology, 31(6): 2008-2019. doi: 10.13544/j.cnki.jeg.2021-0537.

    非均质断层破碎带盾构开挖面极限支护力上限解

    UPPER BOUND SOLUTION OF SHIELD TUNNEL FACE SUPPORTING PRESSURE IN NON-HOMOGENEOUS FAULT FRACTURE ZONE

    • 摘要: 盾构施工穿越断层破碎带具有普遍性,而现有的黏聚力沿深度线性变化模型不能充分反应断层破碎带的倾斜性和非均质性,针对这一问题,引入非均质方向角和非均质系数角分别描述断层破碎带的倾斜性、非均质性和非均质系数大小,提出空间非均质分布函数模型。将模型应用于极限分析上限法,推导了盾构穿越断层破碎带隧道开挖面极限支护压力的计算公式,通过算例和工程实例验证了空间非均质分布函数模型的合理性,分析了在不同非均质方向下内摩擦角、黏聚力、埋深比、非均质系数对开挖面稳定性的影响。结果表明:非均质系数角α=90°时,非均质方向角μ的变化对隧道开挖面支护压力无影响;非均质方向角μ≠0°且非均质系数ρ>0时,开挖面支护压力随非均质方向角、内摩擦角、黏聚力、埋深比、非均质系数的增加而减小;非均质方向角μ=0°且H/D≥1时,开挖面支护压力不受埋深比变化影响。非均质方向角对破坏模式形状的影响大于对破坏范围的影响,内摩擦角对破坏模式的形状和范围均有较大影响,非均质方向角和内摩擦角的增大使得开挖面前方塌落体由拱顶往下滑的趋势转变为由前方滑落,针对不同非均质方向角和内摩擦角的断层破碎带的加固侧重点应有所不同。研究结果为确定断层破碎带中盾构开挖面极限支护压力提供了一种可行的计算方法。

       

      Abstract: The shield construction through fault fracture zone is universal,and the existing non-homogeneous model cannot fully respond to the inclination and non-homogeneity of the fault fracture zone. To address this problem,we proposed a spatial non-homogeneous distribution function model. We described the inclination,non-homogeneous and non-homogeneous coefficient size of the fault fragmentation zone by introducing the non-homogeneous direction angle and non-homogeneous coefficient angle,respectively. Then,the model was applied to the limit analysis upper bound method. We derived the calculation formula of the ultimate supporting pressure at the excavation surface of shield tunneling through fault fracture zone. We also verified the rationality of the spatial non-homogeneous distribution function model by calculation examples and engineering examples. Finally,we analyzed the effects of internal friction angle,cohesion,burial depth ratio,and non-homogeneous coefficient on the stability of the excavation surface under different non-homogeneous directions. The results show the follows. The change of the non-homogeneous direction angle has a great influence on the supporting pressure and failure mode of the tunnel excavation surface. The supporting pressure of excavation face decreases with the increase of non-homogeneous direction angle,internal friction angle,cohesion,burial depth ratio and non-homogeneous coefficient. The increase of non-homogeneous directional angle and internal friction angle makes the collapsing body in front of the excavation face change from the trend of sliding downward from the vault to sliding downward from the front. The reinforcement focus should be different for the fault fragmentation zone with different non-homogeneous directional angle and internal friction angle.

       

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