福建梅花山隧道岩爆机理的数值模拟分析研究  

Numerical Simulation of the Rockburst Mechanism in the Meihuashan Tunnel

作　　者：张倚逾 邢博瑞[2] 宋成科[3] 

机构地区：[1]中铁五局集团有限公司,贵阳550003 [2]中国地质大学(北京)工程技术学院,北京100083 [3]中国地震局第一监测中心,天津300180

出　　处：《现代隧道技术》2014年第1期97-104,共8页Modern Tunnelling Technology

摘　　要：受隧道分步施工开挖顺序的影响,隧道围岩内将会产生应力应变的非线性变化,在高地应力区域这种力学效应将更加明显,并会引起岩爆、片帮等严重地质灾害。文章结合福建梅花山铁路隧道工程实例,利用3D-Sigma软件建立三维隧道开挖数值模型,以实测应力数据为边界条件并利用Hoek-Brown强度准则估算确定岩体的输入参数,分析了开挖过程中开挖步骤的相互影响,以及隧道的三维时空应力场的变化规律。结果表明,隧道在高地应力作用下,拱顶形成压应力集中,拱肩位置形成了剪应力集中,这些应力集中导致洞壁围岩发生脆性破坏,并且后续的开挖作业会影响先前开挖成型的洞段,导致应力集中作用更为明显,加重围岩的破坏;工程实践中实际发生岩爆的位置与数值模拟结果中显示的最大压应力和最大剪应力集中位置对应良好,证明数值模拟结果能很好地揭示该隧道岩爆发生的孕育机理和规律性。Affected by staged excavation, stress-strain nonlinear variation may occur inside the surrounding rock of a tunnel. In high-ground-stress areas, this mechanical effect tends to be even more obvious and can cause serious geological disasters like rockbursts and wall caving, etc. Taking the construction of the Meihuashan tunnel in Fujian as an example, this paper analyzes the interaction of the excavation steps and the change rule of the 3D stress field and strain field in the tunnel by establishing a 3D excavation numerical model with 3D-Sigmasoftware, using the measured stress data as a boundary condition and determining the inputs of the rock mass with the Hoek-Brown strength criterion. The results show that： because of high ground stress, compressive stress concentration occurs at the tunnel crown and shear stress concentration occurs at the spandrel, which may cause brittle failure at the tunnel wall; previously excavated tunnel sections may be affected by subsequent excavation, making the stress concentration effect more obvious and the failure of the surrounding rock more serious; the actual rockburst locations correspond with the locations of maximum compressive stress concentration and maximum shear stress concentration in simulation analysis. The numerical simulation can clearly reveal the mechanism and the possible law of the rock burst, providing strong technical support for engineering applications.

关 键 词：铁路隧道 数值模拟 岩爆机理 

分 类 号：U457.5[建筑科学—桥梁与隧道工程] TU311.4[交通运输工程—道路与铁道工程]