COMPARISONS AND APPLICATIONS OF DISPLACEMENT RELEASE COEFFICIENTS FOR A CIRCULAR ROCK TUNNEL SUBJECTED TO ISOTROPIC GEOSTRESSES
ZHANG Changguang1,ZENG Kaihua2
(1. School of Civil Engineering,Chang?an University,Xi?an,Shaanxi 710061,China;2. Jiangxi Provincial Engineering Research Center of the Special Reinforcement and Safety Monitoring Technology in Hydraulic and Civil Engineering,
Nanchang Institute of Technology,Nanchang,Jiangxi 330099,China)
Abstract:The deformation of tunnel at early stage is of critical importance to determine the support pressure and stable deformation of rock mass using the convergence-confinement method. Some typical formulae of displacement release coefficient for deep circular rock tunnels were summarized,classified and compared in terms of the applicability and the spatial effect of tunnel face. The differences from the convergence-confinement analysis due to the different coefficients of displacement release,different positions of support installing and different control objectives were discussed. It was found that the coefficient of displacement release dependent on the ultimate plastic radius of rock mass was applicable to both the elastic and the elasto-plastic rocks and therefore had wide prospects of engineering applications. The coefficients of elastic displacement release were found to be only applicable to the elastic rock,while the commonly used coefficients of plastic displacement release were only suitable for the rock tunnel with a normalized radius of 2. The support designed according to the support pressure distant from the tunnel face could not be moved forward arbitrarily and a reasonable and timely support with different stiffness should be designed according to the properties of rock mass.
张常光1,曾开华2. 等值地应力下岩质圆形隧道位移释放系数比较及应用[J]. 岩石力学与工程学报, 2015, 34(03): 498-510.
ZHANG Changguang1,ZENG Kaihua2. COMPARISONS AND APPLICATIONS OF DISPLACEMENT RELEASE COEFFICIENTS FOR A CIRCULAR ROCK TUNNEL SUBJECTED TO ISOTROPIC GEOSTRESSES. , 2015, 34(03): 498-510.