Study On Numerical Model Of Underground Reinforced Concrete Structures Corrosion Damage And Its Monitoring Method

The city’s infrastructure projects are gradually shifting from underground buildings to underground buildings.However,the environment of underground structures is more complex than the upper ones.Show more and more building operations,underground construction is affected by many factors,aggravate the damage process of concrete structure,concrete structure caused by rapid deterioration,eventually making early damage of underground buildings.And in the underground environment,the construction of the project is difficult,unexpected events and remedial methods are scarce.Therefore,monitoring and damage assessment of underground concrete structure becomes an essential key link.The monitoring technology of concrete corrosion damage and the model of steel corrosion in concrete structure are studied in this paper.Firstly,the research status of reinforcement corrosion in concrete is expounded,and the mechanism of reinforcement corrosion and the cause and process of corrosion expansion cracking are analyzed.The main factors affecting the corrosion of reinforced concrete in concrete are studied,and the model of corrosion expansion force and the corrosion rate of reinforced concrete in concrete are summarized.Provide the basis for the later model’s implementation.Then,according to the principle of optical fiber sensing technology,characteristics and construction requirements,the design of a real-time process monitoring device based on optical fiber sensing technology.According to the experimental research,the FBG sensor is used to monitor the corrosion damage of underground concrete structures.Under the laboratory condition,the constant current accelerated corrosion test method was used to simulate the time variation of the whole process of corrosion damage and cracking of concrete structures in corrosive environment,and the experimental results were analyzed.Then,through the study of the mechanism of corrosion of rebar in underground concrete and the monitoring of the test,the corrosion products in the corrosion process are regarded as irregular shapes and radial radial diffusion with time.In the calculation,the corrosion product is divided into n sub regions along the circumferential direction,and the volume of the expanded volume in each sub region is equivalent to the displacement increment.A discrete model of corrosion expansion considering time variation is established;The nonlinear spring is used to simulate the action of corrosion expansion products on concrete.A numerical model of concrete swelling damage is established by using the smeared cracking model;A time-dependent numerical model of concrete structure damage based on discrete corrosion expansion model is proposed.Finally,the ABAQUS finite element analysis software is used to combine the discrete damage expansion model of concrete structure damage time varying numerical model.In this paper,the whole process of steel corrosion expansion is studied under different conditions such as thickness,angle zone and non angle zone.It is proved that the damage time varying numerical model of concrete structure and the monitoring device based on optical fiber sensor are feasible.