Linearization of the Hoek and Brown rock failure criterion for tunnelling in elasto-plastic rock masses
Linearization of the Hoek and Brown rock failure criterion for tunnelling in elasto-plastic rock masses
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DOI：
10.1016/j.ijrmms.2007.12.003
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发表时间：
2008-10
影响因子：
7.2
通讯作者：
R. Jimenez;R. Jimenez;A. Serrano;C. Olalla
中科院分区：
文献类型：
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作者：
R. Jimenez;R. Jimenez;A. Serrano;C. Olalla
我们提出了一种新的方法来估计等效Mohr-Coulomb强度参数，可用于设计支持隧道的弹塑性岩体满足非线性经验Hoek-Brown破坏准则。我们的工作与一个通用的adimensional制定的Hoek-Brown故障准则的归一化的Lambe的变量的平面应力的空间，我们进行线性化考虑应力场在塑性区周围的隧道。使用一系列基准测试用例的解析解验证了该程序。数值解也被用来验证的情况下，解析解是不可用的程序。结果表明，应力场在塑性区周围的隧道，以及线性化方法和质量的岩体，有显着的影响，计算估计等效莫尔-库仑强度参数。数值分析的结果也表明，我们提出的线性化方法可以用来估计隧道支护系统上的负载和力矩。当隧道支护压力精确已知时，推荐采用等效模型响应（EMR）方法计算等效Mohr-Coulomb强度参数，并进一步表明，新引入的线性化方法可作为现有应力范围内最佳拟合（BFe）和人工应力范围内最佳拟合（BFa）方法的替代方法，当与Hoek-Brown岩体响应的差异具有工程意义（例如超过10%）时，提供的性能估计通常优于BFe和BFa方法的估计。
We present a novel methodology for estimation of equivalent Mohr–Coulomb strength parameters that can be used for design of supported tunnels in elasto-plastic rock masses satisfying the non-linear empirical Hoek–Brown failure criterion. We work with a general adimensional formulation of the Hoek–Brown failure criterion in the space of normalized Lambe's variables for plane stress, and we perform linearization considering the stress field in the plastic region around the tunnel. The procedure is validated using analytical solutions to a series of benchmark test cases. Numerical solutions are also employed to validate the procedure in cases for which analytical solutions are not available. Results indicate that the stress field in the plastic region around the tunnel, as well as the linearization method employed and the quality of the rock mass, has a significant impact on computed estimates of equivalent Mohr–Coulomb strength parameters. Results of numerical analyses also show that our proposed linearization method can be employed to estimate loads and moments on the tunnel support system. We recommend the equating model responses (EMR) method to compute equivalent Mohr–Coulomb strength parameters when the tunnel support pressure is accurately known, and we further show that our newly introduced linearization method can be employed as an alternative to the best fitting in the existing stress range (BFe) and best fitting in an artificial stress range (BFa) methods, providing performance estimates that are generally better than estimates of the BFe and BFa methods when differences with the response of the Hoek–Brown rock mass are of engineering significance (say more than 10%).