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A platform for research: civil engineering, architecture and urbanism
Analytical Study of the Bolts-Grouting Reinforcement in Cylindrical Lined Tunnels Considering Seepage
https://orcid.org/0000-0002-0430-3549
Abstract Bolts-grouting reinforcement method can reduce the water inflow and strengthen the surrounding rock in the tunnel with a quantity of water seepage. However, there are few analytical theories of this bolts-grouting reinforcement considering seepage for these water-rich tunnels. This paper proposed a closed-form solution for the bolts-grouting reinforcement of surrounding rock under axisymmetric conditions. Based on Darcy's law and Terzaghi’s effective stress principle, the force of the rockbolts on the surrounding rock and pore water pressure was substituted into the equilibrium equation of the surrounding rock, and the effect of grouting reinforcement was considered by the shear modulus and permeability coefficient of the surrounding rock. Besides, the “smeared” method was used to calculate the system effect of rockbolts. The results obtained with the closed-form solution were shown to be equivalent to the results of the same problem solved by finite element methods. The effect of bolts-grouting reinforcement parameters on the maximum shear stress and displacement at the inner edge of the surrounding rock under different support pressure and impermeability pressure was discussed. It is more conducive to controlling the maximum shear stress and deformation of the surrounding rock with the increase of the number of rockbolts and the decrease of the length of each rockbolt under the same total length of rockbolts. The impermeability pressure has a negative impact on the control of the maximum shear stress and deformation of the surrounding rock. However, the support pressure was beneficial to reinforce the surrounding rock. A bolts-grouting design included pre-grouting, and optimization method has been developed for a section of the Gaoligongshan tunnel with the average RMR-value of 51 and $ RMR_{TBM} $ of 63 based on our closed-form solution. The monitoring data suggested that the optimum design method can ensure the safety of the tunnel while making full use of the tensile properties and reducing the length of the rockbolts.
Highlights A closed-form solution considering both rockbolts and grouting reinforcement under seepage was proposed.The increase of the number of rockbolts and decrease of the length of each rockbolt have a better reinforcement performance for the surrounding rock.The impermeability pressure has a negative impact on the control of the stress and deformation in the surrounding rock.An optimal design method of bolts-grouting parameters is proposed based on our analytical solution.
Analytical Study of the Bolts-Grouting Reinforcement in Cylindrical Lined Tunnels Considering Seepage
https://orcid.org/0000-0002-0430-3549
Abstract Bolts-grouting reinforcement method can reduce the water inflow and strengthen the surrounding rock in the tunnel with a quantity of water seepage. However, there are few analytical theories of this bolts-grouting reinforcement considering seepage for these water-rich tunnels. This paper proposed a closed-form solution for the bolts-grouting reinforcement of surrounding rock under axisymmetric conditions. Based on Darcy's law and Terzaghi’s effective stress principle, the force of the rockbolts on the surrounding rock and pore water pressure was substituted into the equilibrium equation of the surrounding rock, and the effect of grouting reinforcement was considered by the shear modulus and permeability coefficient of the surrounding rock. Besides, the “smeared” method was used to calculate the system effect of rockbolts. The results obtained with the closed-form solution were shown to be equivalent to the results of the same problem solved by finite element methods. The effect of bolts-grouting reinforcement parameters on the maximum shear stress and displacement at the inner edge of the surrounding rock under different support pressure and impermeability pressure was discussed. It is more conducive to controlling the maximum shear stress and deformation of the surrounding rock with the increase of the number of rockbolts and the decrease of the length of each rockbolt under the same total length of rockbolts. The impermeability pressure has a negative impact on the control of the maximum shear stress and deformation of the surrounding rock. However, the support pressure was beneficial to reinforce the surrounding rock. A bolts-grouting design included pre-grouting, and optimization method has been developed for a section of the Gaoligongshan tunnel with the average RMR-value of 51 and $ RMR_{TBM} $ of 63 based on our closed-form solution. The monitoring data suggested that the optimum design method can ensure the safety of the tunnel while making full use of the tensile properties and reducing the length of the rockbolts.
Highlights A closed-form solution considering both rockbolts and grouting reinforcement under seepage was proposed.The increase of the number of rockbolts and decrease of the length of each rockbolt have a better reinforcement performance for the surrounding rock.The impermeability pressure has a negative impact on the control of the stress and deformation in the surrounding rock.An optimal design method of bolts-grouting parameters is proposed based on our analytical solution.
Analytical Study of the Bolts-Grouting Reinforcement in Cylindrical Lined Tunnels Considering Seepage
https://orcid.org/0000-0002-0430-3549
Abstract Bolts-grouting reinforcement method can reduce the water inflow and strengthen the surrounding rock in the tunnel with a quantity of water seepage. However, there are few analytical theories of this bolts-grouting reinforcement considering seepage for these water-rich tunnels. This paper proposed a closed-form solution for the bolts-grouting reinforcement of surrounding rock under axisymmetric conditions. Based on Darcy's law and Terzaghi’s effective stress principle, the force of the rockbolts on the surrounding rock and pore water pressure was substituted into the equilibrium equation of the surrounding rock, and the effect of grouting reinforcement was considered by the shear modulus and permeability coefficient of the surrounding rock. Besides, the “smeared” method was used to calculate the system effect of rockbolts. The results obtained with the closed-form solution were shown to be equivalent to the results of the same problem solved by finite element methods. The effect of bolts-grouting reinforcement parameters on the maximum shear stress and displacement at the inner edge of the surrounding rock under different support pressure and impermeability pressure was discussed. It is more conducive to controlling the maximum shear stress and deformation of the surrounding rock with the increase of the number of rockbolts and the decrease of the length of each rockbolt under the same total length of rockbolts. The impermeability pressure has a negative impact on the control of the maximum shear stress and deformation of the surrounding rock. However, the support pressure was beneficial to reinforce the surrounding rock. A bolts-grouting design included pre-grouting, and optimization method has been developed for a section of the Gaoligongshan tunnel with the average RMR-value of 51 and $ RMR_{TBM} $ of 63 based on our closed-form solution. The monitoring data suggested that the optimum design method can ensure the safety of the tunnel while making full use of the tensile properties and reducing the length of the rockbolts.
Highlights A closed-form solution considering both rockbolts and grouting reinforcement under seepage was proposed.The increase of the number of rockbolts and decrease of the length of each rockbolt have a better reinforcement performance for the surrounding rock.The impermeability pressure has a negative impact on the control of the stress and deformation in the surrounding rock.An optimal design method of bolts-grouting parameters is proposed based on our analytical solution.
Analytical Study of the Bolts-Grouting Reinforcement in Cylindrical Lined Tunnels Considering Seepage
Ma, Wenzhu (author) / Song, Yixiang (author) / Zhang, Song (author) / Gu, Dongming (author) / Zhang, Jiwei (author)
2022
Article (Journal)
Electronic Resource
English
BKL:
38.58
Geomechanik
/
56.20
Ingenieurgeologie, Bodenmechanik
/
38.58$jGeomechanik
/
56.20$jIngenieurgeologie$jBodenmechanik
RVK:
ELIB41
Earth dam grouting seepage prevention and reinforcement method
| European Patent Office | 2020