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Stability Evaluation for the Lining Structures of Tunnels with Large Corrosion
Areas in Sulfate Environment
(1. Zhangjiajie Works Section, China Railway Guangzhou Bureau Group Co., Ltd., Zhangjiajie 427000; 2. School of Civil Engineering, Central South University, Changsha 410075)
Abstract The stability evaluation for tunnel lining structure in service is the key basis for maintenance and rein?
forcement. As for the HTG tunnel project, this paper established a load-structure method based calculation model of tunnel lining with large areas of corrosion, and in terms of corrosion depth and scope, the stress conditions and safety coefficient distribution characteristics of tunnel lining structure were calculated and analyzed under different working conditions. The results show that after occurring large areas of corrosion in the tunnel lining, the change of axial force of lining structure is small, the change of internal force of structure is mainly reflected in the change of bending moment of lining, which leads to the increase of eccentricity of lining element. The tunnel side wall and arch foot belong to the dangerous area of corrosion. When the tunnel lining at those parts has a large area of corrosion, the number of dangerous sections of the tunnel lining is larger, and the overall stability of the tunnel lining
structure is in danger. On this basis, the tunnel lining is divided into a series structure system composed of five subsystems, and a calculation method is proposed for evaluating the safety level of the corroded tunnel lining structure based on cross section safety probability. It was applied to the HTG tunnel project, the safety probability and safe level were obtained with respect to the sulfate corrosion conditions in different tunnel lining positions. It can provide a basis for the maintenance and reinforcement of tunnel lining.
Abstract:
The stability evaluation for tunnel lining structure in service is the key basis for maintenance and rein?
forcement. As for the HTG tunnel project, this paper established a load-structure method based calculation model of tunnel lining with large areas of corrosion, and in terms of corrosion depth and scope, the stress conditions and safety coefficient distribution characteristics of tunnel lining structure were calculated and analyzed under different working conditions. The results show that after occurring large areas of corrosion in the tunnel lining, the change of axial force of lining structure is small, the change of internal force of structure is mainly reflected in the change of bending moment of lining, which leads to the increase of eccentricity of lining element. The tunnel side wall and arch foot belong to the dangerous area of corrosion. When the tunnel lining at those parts has a large area of corrosion, the number of dangerous sections of the tunnel lining is larger, and the overall stability of the tunnel lining
structure is in danger. On this basis, the tunnel lining is divided into a series structure system composed of five subsystems, and a calculation method is proposed for evaluating the safety level of the corroded tunnel lining structure based on cross section safety probability. It was applied to the HTG tunnel project, the safety probability and safe level were obtained with respect to the sulfate corrosion conditions in different tunnel lining positions. It can provide a basis for the maintenance and reinforcement of tunnel lining.
DUAN Lian1 LI Yongheng2 WU Jianghang1
.Stability Evaluation for the Lining Structures of Tunnels with Large Corrosion
Areas in Sulfate Environment[J] MODERN TUNNELLING TECHNOLOGY, 2022,V59(5): 212-220