Squeezing ground in tunneling is associated with large deformation of the tunnel face. In this study, squeezing characteristics of the ground and rock conditions in Golab water conveyance tunnel, Iran, are discussed a...Squeezing ground in tunneling is associated with large deformation of the tunnel face. In this study, squeezing characteristics of the ground and rock conditions in Golab water conveyance tunnel, Iran, are discussed and the classification of squeezing behavior around zones where the problems occurred is presented. The squeezing conditions were investigated using empirical and semi empirical methods. In the next step, creep convergence of the tunnel with Burger's model was simulated by the numerical method. Numerical analysis showed that wall displacement(64.1 mm) of the Golab tunnel was more than allowable strain(1% of the tunnel diameter), therefore, it was found that squeezing phenomenon could exist, leading to the failure of the support system. Numerical analysis at the phyllite-slate zone also showed squeezing conditions due to the weakness of rock mass and high overburden that this situation cause failure in the segmental lining. In this research, failure in segmental lining in phyllite-slate zone verified the results of the numerical modeling.展开更多
A stability of a nonlinear ultra-long wave and its solution are discussed in this paper by employing Burger model which is subject to heat resource. It is of interest noted that the wave solution can be described by a...A stability of a nonlinear ultra-long wave and its solution are discussed in this paper by employing Burger model which is subject to heat resource. It is of interest noted that the wave solution can be described by an equation of KDV or MKDV and that conditions for the existence of the solution are related to characteristic divergences. In addition, a wave velocity expression for nonlinear ultra-long waves and some diagnostic correlations among wave parameters have been obtained.展开更多
文摘Squeezing ground in tunneling is associated with large deformation of the tunnel face. In this study, squeezing characteristics of the ground and rock conditions in Golab water conveyance tunnel, Iran, are discussed and the classification of squeezing behavior around zones where the problems occurred is presented. The squeezing conditions were investigated using empirical and semi empirical methods. In the next step, creep convergence of the tunnel with Burger's model was simulated by the numerical method. Numerical analysis showed that wall displacement(64.1 mm) of the Golab tunnel was more than allowable strain(1% of the tunnel diameter), therefore, it was found that squeezing phenomenon could exist, leading to the failure of the support system. Numerical analysis at the phyllite-slate zone also showed squeezing conditions due to the weakness of rock mass and high overburden that this situation cause failure in the segmental lining. In this research, failure in segmental lining in phyllite-slate zone verified the results of the numerical modeling.
文摘A stability of a nonlinear ultra-long wave and its solution are discussed in this paper by employing Burger model which is subject to heat resource. It is of interest noted that the wave solution can be described by an equation of KDV or MKDV and that conditions for the existence of the solution are related to characteristic divergences. In addition, a wave velocity expression for nonlinear ultra-long waves and some diagnostic correlations among wave parameters have been obtained.