Monitoring And Analysis Of The Temperature Stress Of Mass Concrete In The Foundation Of Shaking Table Array

Shaking table foundation is a device that provides reaction force for shaking tableand its casting quality is closely related to the working system of the whole shaking table.An university is about to build a large multi-functional vibratory platform array laboratory,the vibratory platform array foundation adopts the open channel shape and the table can be arbitrarily shifted and assembled in the channel.The areas of platform array foundation is about 1288m~2,the thickness of foundation is 8m,and the total amount of concrete pouring is about 5800m~3,which belongs to the mass concrete structure.The research on mass concrete structure has been a hot topic in China or forign.Most researchers focus on water conservancy dam,large house construction foundation,road and bridge engineering,while the research on temperature field and stress field of mass concrete for shaking table foundation is relatively few.Therefore,it is necessary to study the distribution of temperature field and stress field of mass concrete on shaking table foundation and further study the prevention and control measures of temperature crack of mass concrete on shaking table foundation.Based on a large multifunctional vibration table array of the construction of colleges and universities laboratory foundation of vibration table array as the research object,the temperature stress of array based on layered casting with integral pouring during the construction was carried on the simulation through the finite element analysis software MIDAS/FEA,the results show that the temperature stress is not beyond its corresponding instars for the mass concrete of platform array foundation with layered pouring,,whereas there are risks of cracking of concrete for the mass concreat that adopts the way of whole casting during construction.It provides a theoretical basis for the pouring work of platform array foundation on the basis of the analysis of the engineering of several commonly used temperature control measures.After completing the second pouring work on the foundation of the platform,The real-time temperature monitoring during the construction of the side wall of array was carried out,and the measured data was analyzed,which provides quantitative data for a comprehensive understanding of the temperature field distribution of the foundation side wall of the array.The comparing analysis between the measured data and the calculation data of MIDAS/FEA was carriedout,the results show that the temperature field distribution of the two is in good agreement.At the end of the article,a feature part of the side wall of the array foundation was selected to establish a finite element analysis model,and the finite element analysis software ANSYS was used to simulate the temperature field and stress field of the massive concrete considering the action of steel The research content includes the effects of the internal reinforcement,reinforcement ratio,and steel bar diameter on the influence of the mass concrete temperature field and stress field,the results show that the appropriate amount of reinforcing steel in the large volume concrete can improve the thermal performance of the concrete on the one hand,and can also improve the mechanical properties of the reinforced concrete on the other hand.Finally,the effect of steel bars on the temperature and stress fields of mass concrete was analyzed.The research results of this paper have certain theoretical and practical value for the prevention and control of temperature crack in other mass concrete structures of vibratory platform array foundation,and provide reference for the pouring work of mass concrete of vibratory platform array foundation.