Shen Caihua, Zeng Zhikang, Lou Huibo, Yang Zhifan, Gu Wenbo
School of Civil Engineering and Transportation, Hohai University, Nanjing, 210098, China.
Ningbo Weida Highway Development Co., Ltd., Ningbo, 315500, China.
Sci Rep. 2024 Oct 30;14(1):26088. doi: 10.1038/s41598-024-78005-1.
Determining rock mass mechanical parameters and accurately predicting tunnel deformation during tunnel construction remain challenging tasks. This study introduces a novel approach to calculate the Geological Strength Index by integrating indoor rock mechanics tests with geometric data from three-dimensional dense reconstruction. We utilized the Hoek-Brown strength criterion to develop a theoretical model for predicting tunnel deformation in fractured rock masses. Case studies reveal that the average value of Geological Strength Index for the Xiamen highway tunnel's surrounding rock is 44. With support from the lining structure equivalent to 0.002-0.02 times the initial in-situ stress, the plastic zone thickness decreased by approximately 50%, and radial displacement was reduced by about 40%. Enhancing the lining structure's support pressure significantly reduces the plastic zone radius and radial displacement. As the Geological Strength Index decreases, the nonlinearity between support pressure and plastic zone radius becomes more pronounced, with a similar trend observed for the relationship between support pressure and tunnel radial displacement. The relative deviation between predicted and measured values did not exceed 1.69%. The method accurately captures the effects of rock fragmentation and tunnel construction on plastic zone formation and displacement, offering an effective approach for the rapid and secure assessment of rock tunnel excavation stability using digital technology.
确定岩体力学参数并准确预测隧道施工期间的隧道变形仍然是具有挑战性的任务。本研究引入了一种新方法，通过将室内岩石力学试验与三维密集重建的几何数据相结合来计算地质强度指标。我们利用Hoek-Brown强度准则建立了一个预测裂隙岩体中隧道变形的理论模型。案例研究表明，厦门公路隧道围岩的地质强度指标平均值为44。在相当于初始地应力0.002 - 0.02倍的衬砌结构支护下，塑性区厚度减少了约50%，径向位移减少了约40%。提高衬砌结构的支护压力可显著减小塑性区半径和径向位移。随着地质强度指标的降低，支护压力与塑性区半径之间的非线性变得更加明显，支护压力与隧道径向位移之间的关系也呈现类似趋势。预测值与测量值之间的相对偏差不超过1.69%。该方法准确地捕捉了岩石破碎和隧道施工对塑性区形成和位移的影响，为利用数字技术快速、安全地评估岩石隧道开挖稳定性提供了一种有效方法。
