Large deformations such as roof subsidence,floor heave,and two-sided deformations occur frequently in deep soft-rock roadways.The deformation becomes more severe under the combined effect of high in-situ and mining-in...Large deformations such as roof subsidence,floor heave,and two-sided deformations occur frequently in deep soft-rock roadways.The deformation becomes more severe under the combined effect of high in-situ and mining-induced stresses,which detrimentally affect the safe mining of coal.Based on the geological conditions and roadway failure characteristics of the Nanyaotou coal mine in Shanxi province,China,we used comprehensive numerical simulations and field observations to study roadway deformation and failure.The deformation mechanism of deep soft-rock roadways under dynamic pressures is described,and the corresponding control measures are proposed.The deformation and fracture development characteristics of roadways surrounding rocks were explored with a primary support scheme,and its effects were evaluated.The radius of the plastic zone and the displacement deformation of the roadway were studied by using theoretical analysis,and a combined-support design of‘‘anchor bolt+anchor cable+shotcrete+deep and shallow borehole grouting+inverted arch”was proposed to limit deformations and relieve the stress in the surrounding rocks.Numerical simulations and field monitoring showed that the combined support scheme can effectively mitigate the large deformations of ventilation roadways and provide guidance for the stable control of deep soft-rock roadways.展开更多
In this paper,the results of a parametric study on groundwater drawdown-induced surface settlement during tunneling in waterbearing ground are presented.A calibrated stress–pore pressure coupled finite element model ...In this paper,the results of a parametric study on groundwater drawdown-induced surface settlement during tunneling in waterbearing ground are presented.A calibrated stress–pore pressure coupled finite element model was adopted for the parametric analysis.The results were analyzed to establish the relationships between key design issues,such as the ground surface settlement and groundwater drawdown,and influencing factors.An artificial neural network(ANN)-based sensitivity analysis was performed to obtain insight into the relative importance of the influencing factors.The results indicated that the primary influencing factors on the settlement development are the thickness and stiffness of the soil layer within the drawdown zone and the lining permeability,while the initial void ratio and the permeability of the soil layer were considered secondary influencing factors.Practical implications and findings of the study are discussed.展开更多
基金supported by the Key Projects of the Joint Fund of the National Natural Science Foundation of China(Grant No.U21A20107)the National Natural Science Foundation of China(Grant No.52074239)+1 种基金The financial support by the National Research Foundation of Korea(Grant Number:NRF-2021R1A2C3011490)also greatly appreciated.
文摘Large deformations such as roof subsidence,floor heave,and two-sided deformations occur frequently in deep soft-rock roadways.The deformation becomes more severe under the combined effect of high in-situ and mining-induced stresses,which detrimentally affect the safe mining of coal.Based on the geological conditions and roadway failure characteristics of the Nanyaotou coal mine in Shanxi province,China,we used comprehensive numerical simulations and field observations to study roadway deformation and failure.The deformation mechanism of deep soft-rock roadways under dynamic pressures is described,and the corresponding control measures are proposed.The deformation and fracture development characteristics of roadways surrounding rocks were explored with a primary support scheme,and its effects were evaluated.The radius of the plastic zone and the displacement deformation of the roadway were studied by using theoretical analysis,and a combined-support design of‘‘anchor bolt+anchor cable+shotcrete+deep and shallow borehole grouting+inverted arch”was proposed to limit deformations and relieve the stress in the surrounding rocks.Numerical simulations and field monitoring showed that the combined support scheme can effectively mitigate the large deformations of ventilation roadways and provide guidance for the stable control of deep soft-rock roadways.
基金This work was supported by Grant No.2014004636 from the Basic Research Program of the Korea Science&Engineering Foundation as well as Grant No.13CCTI-T01 from the Ministry of Land,Transport and Maritime Affairs,Korea.The financial support is gratefully acknowledged.
文摘In this paper,the results of a parametric study on groundwater drawdown-induced surface settlement during tunneling in waterbearing ground are presented.A calibrated stress–pore pressure coupled finite element model was adopted for the parametric analysis.The results were analyzed to establish the relationships between key design issues,such as the ground surface settlement and groundwater drawdown,and influencing factors.An artificial neural network(ANN)-based sensitivity analysis was performed to obtain insight into the relative importance of the influencing factors.The results indicated that the primary influencing factors on the settlement development are the thickness and stiffness of the soil layer within the drawdown zone and the lining permeability,while the initial void ratio and the permeability of the soil layer were considered secondary influencing factors.Practical implications and findings of the study are discussed.
