围岩力学参数对小净距隧道初期支护受力影响的研究

Study on Influence of Mechanical Parameters of Surrounding Rock on Stress in Initial Supporting to Small Spacing Tunnel

以青岛地铁8号线胶州湾海底隧道工程为依托,研究各围岩力学参数在小净距隧道开挖过程中的重要程度。根据控制变量法选取了弹性模量,泊松比,黏聚力和内摩擦角进行数值模拟研究。运用三维有限差分模型,对泵站施工进行了模拟计算。结果表明:两侧隧道的最大主应力和周边位移随泊松比的增大而增大,随弹性模量等参数的增大而减小;隧道结构力学响应对内摩擦角的变化最敏感,对于应力方面,泊松比变化最不敏感;对于侧面竖向位移方面,黏聚力最不敏感。

Based on the submarine tunnel engineering in Jiaozhou Bay of Qingdao Metro Line 8, the importance of the mechanics parameters of surrounding rock in the course of small spacing tunnel excavation was studied herein and, by control variable method, elastic modulus, Poisson’s ratio, cohesion force and internal friction angle were selected for numerical simulation. Then the construction of pumping station was simulated depending on three-dimensional finite difference model. The result shows that, the maximum principal stress and the peripheral displacement increase with the increase of Poisson’s ratio and decrease with the increase of elastic modulus and other parameters;the mechanical response of tunnel structure is most sensitive to the change of internal friction angle and, as to the stress, it is least sensitive to the change of Poisson’s ratio, as to lateral vertical displacement, it is least sensitive to cohesion force.