Research On Temperature Monitoring And Temperature Crack Control Of Subway Station Baseboard Based On Distributed Optical Fiber

Concrete material has been widely used in construction engineering,because of its own outstanding characteristics,compared with other building materials concrete material has incomparable excellent physical properties and good economic benefits.In some large construction projects,such as dam construction in water conservancy and hydropower,super high-rise building foundation,large bridge piers,subway station floor and other projects need to use large volume concrete structure.Subway station floor is usually made of mass concrete to ensure its integrity and safety,however,there is a non-negligible problem in the mass concrete structure,which is the temperature stress caused by the temperature rise of the internal structure of the cement material hydration zone.If the temperature control of mass concrete is improper,the temperature difference between inside and outside is too large,the temperature stress will exceed the allowable tensile strength of concrete,and the mass concrete structure will therefore produce temperature cracks,affecting the safety and durability of the structure.At present,the temperature monitoring of mass concrete structure still can not get enough attention,because of ignoring the temperature monitoring and temperature control of mass concrete structure,some mass concrete projects form temperature cracks,resulting in huge economic losses.Based on this consideration,the real-time temperature monitoring of mass concrete is particularly important,can help the employees to master exothermic regularity of subway station floor mass concrete and the rule of the temperature,so as to take reasonable cooling measures,ensure the engineering quality,reduce the economic loss,so the effective temperature monitoring is an important prerequisite for the prevention and control of mass concrete temperature crack.This paper is based on the basis of previous studies,starting from the theory and the field test,using distributed optical fiber technology a period of mass concrete structure in the subway station floor monitoring research,given a set of complete distributed optical fiber temperature monitoring scheme and fiber laying method,and analyze and summarize the monitoring data,calculate the temperature stress and fracture analysis of the segment.This paper introduces the principle of heat conduction and the principle of temperature field solution through the finite element temperature field theory,and uses the finite element analysis software ANSYS to establish an engineering model to simulate the field construction process,and compares the simulated temperature results with the temperature monitoring results of the field test,and analyzes the rationality of the simulation results using the empirical parameters.JAYA optimization algorithm is introduced to inversion optimization of thermodynamic parameters of mass concrete construction of station floor in actual engineering.Based on actual distributed optical fiber monitoring temperature data,Matlab is used to compile inversion program iterative calculation,and ANSYS is used for simulation calculation through Matlab,so as to obtain thermodynamic parameters similar to this project.Based on this engineering model,some measures to reduce hydration heat and temperature crack of mass concrete are put forward,such as adding ash and using cooling water pipe to reduce temperature,etc.Finite element analysis software is used to analyze,which provides theoretical basis for practical engineering and guidance for similar engineering projects in the future.