Study On Mechanical Properties And Engineering Application Of Tunnel Lining Reinforced By Corrugated Steel Plate Liner

China has a vast territory and a variety of terrain types.Highway and railway tunnels pass through complex geological mountains.In addition to design,construction,operation and other reasons,a large number of tunnel linings have cracks,water leakage,deformation,dislocation,falling blocks and other diseases,and even cause serious accidents such as local collapse.It has a major safety hazard to the normal operation of the tunnel,endangering the safety of personnel and vehicles.According to incomplete statistics,at present,more than 70% of highway and railway tunnels in China have different degrees of diseases,of which 30%～46% reach A1(serious)level diseases,which affect the stability of local or overall lining structure and traffic safety,and need to be repaired and strengthened urgently.Based on the reinforcement project of Jiulingshan Tunnel in Wuji Section of Daguang Expressway,this paper mainly studies the mechanical properties of corrugated steel plate lining reinforced tunnel lining,and develops a corrugated steel plate lining construction method based on uninterrupted traffic tunnel reinforcement trolley.The main research contents and results are as follows :(1)Based on the method of indoor test,the tunnel lining unit is equivalent to a reinforced concrete beam.The post-anchoring method is used to reinforce the specimen and two-point loading test is carried out.The corresponding model is established by ABAQUS finite element software.The test results and numerical analysis are mutually verified.The mechanical mechanism of corrugated steel plate reinforced concrete beam is revealed,and the shear failure mode and crack development law of corrugated steel plate reinforced concrete structure are obtained.(2)The stress variation law of corrugated steel plate in composite beam after anchorage is revealed : in the initial stage of loading,the peak and trough of corrugated steel plate are in the neutral layer,and the strain is basically zero;after reaching the cracking load,the peak of the corrugated steel plate is in a state of compression as a whole,and the mid-span strain is the largest,and the closer to the bearing,the smaller the strain.The trough has been in a tensile state,and also shows the maximum strain in the mid-span,and the closer to the bearing,the smaller the strain.The strain value of the trough is greater than the strain value of the peak,which is close to the tensile strain value of the lower part of the neutral layer of the flange plate.(3)The model of Jiulingshan tunnel is established by using ABAQUS finite element software.Based on the stratum-structure calculation model,the mechanical properties of tunnel lining reinforced by corrugated steel plate lining are studied.The effects of different number of connectors(anchor bolts)and thickness of corrugated steel plate on the reinforcement effect of tunnel lining are explored.The appropriate anchor spacing at different positions of the tunnel ring is proposed.The law that the pressure sharing ratio of lining and corrugated steel liner to surrounding rock is negatively correlated with the increase of corrugated steel plate thickness is obtained.(4)Based on the reinforcement project of Jiulingshan tunnel,the construction method of corrugated steel plate liner based on non-interrupted traffic tunnel reinforcement trolley is developed.The stress and pressure changes of corrugated steel plate liner after reinforcement are analyzed,and the safety and stability of corrugated steel plate liner reinforced tunnel lining are verified.In view of the problems in construction,the corresponding disposal measures are put forward,which has reference significance for similar tunnel maintenance and reinforcement projects.