| Because of the large volume and complicated boundary conditions of the top box of a single-box,double-compartment pier of a long-span prestressed concrete continuous beam bridge,the temperature of the concrete in the initial stage of pouring will cause the temperature to rise sharply.Meanwhile,if temperature control is improperly maintained,temperature cracks can easily occur.For better solving the above mentioned problems,this paper analyzed the the fluid-solid coupling heat transfer system and the thermo-mechanical coupling calculation model considering the influence of the prestressed pipe,to established for the problems caused by the hydrothermal heat generation behavior in the initial stage of mass concrete single-box double-chamber structure pouring.Based on the theory of genetic algorithm and finite element thermal analysis,to put forward an intelligent method for back analysis of adiabatic temperature rise parameters,to in-depth study the thermo-mechanical coupling effect and cooling method of tube cooling in one-tank double-compartment piers of mass concrete considering the influence of prestressed pipes.The main contents are as follows:(1)In-depth studied the inverse analysis method for unknown parameters of concrete heat of hydration and temperature rise,based on the genetic algorithm and finite element software,to set up a mathematical mathematical model for inverse analysis parameters.This study also combined with comprehensive thermal field and flow field boundary constraints,to established an endogenous thermal transient heat conduction analysis model,compared with the field measured data,the rationality of the inverse analysis method and the reliability of the numerical model are verified,revealing that the massive concrete thick wall double the initial temperature distribution of the chamber structure was completed and the structural response characteristics were obtained.(2)In this chapter,the effects of three-dimensional prestressed channels on the temperature field,stress field,and deformation field of the hydration heat of single-chamber double-chamber structure of mass concrete are studied.The same modelling method is used toconsider the effects of the pipeline and ignore the pipeline.Differences in temperature distribution,stress distribution,and deformation distribution of the single-chamber dual-chamber pier during impact.By comparing the theoretical calculation data with the field measurement data,the correctness of the modeling method was verified,and the heat dissipation mechanism of the three-dimensional prestressed hole was revealed.(3)The main content of this chapter is to define ANSYS thermal effect unit load group program Usrsurf116 to construct the finite element thermodynamic model of the concrete single-chamber dual-chamber roof block cold.Through model verification,this paper uses ANSYS program to simulate the modeling and analysis methods of the cooling and cooling process of the top tube of a single tank double-compartment pier,the unit type selection and the rationality of the material property setting.(4)The main content of this chapter is put forward a design program for the cooling of tubes in a single-chamber dual-chamber structure for mass concrete.An endogenous heat optimization control mathematical model was established.Based on the genetic algorithm and the intelligent optimization design of the finite element program,the tube cooling cooling measures applicable to the project background were obtained.Based on the design of the cold temperature control scheme,the refinement analysis of the mass concrete single box double-compartment pier top block under the cooling cooling measures is revealed,revealing the cold temperature cooling measures for large volume concrete thick-walled dual chamber structure heat of hydration the rule of behavior.(5)The main content of this chapter is based on the heat flow solid coupling model.On the basis of the known cooling temperature control scheme of the design tube,the temperature rise peak of the top block of the single box double room pier is analyzed by comparing different water time,different cooling flow velocity,different cooling water temperature,single stage water and stage water.The difference of stress peak value is used to determine the basic principles of cooling parameters design for concrete box girder double box pier. |
PDF Full Text Request