Finite Element Analysis Of Temperature Effect Of Two-way Over-length Basement Structure Considering Pile Foundation Constraints

Over-length concrete structures in civil buildings are restricted by temperature stress of concrete,which will inevitably lead to deformation and cracks in basement structures,and affect the normal application performance use of buildings.This project is based on the Huzhou PPP comprehensive project to carry out finite element analysis.Considering temperature load,soil load,gravity load and the restraint effect of pile foundation on crack development.It is more in line with the actual situation than only considering the influence of temperature load.The finite element model of the basement structure without pile foundation constraints is established to compare and analyze the deformation characteristics and internal force distribution differences between the two models.The main research contents and achievements are as follows.1.The research status of temperature effect,crack control,temperature effect of over-length structure with constraints and calculation of shrinkage and creep are expounded.2.Finite element software ANSYS is used to establish the finite element models of over-length basement structure with or without pile foundation constraints.Analyse the temperature effect,deformation characteristics and internal force distribution of roof,side wall and column in service stage,and the difference of temperature effect between over-length basement structure with or without pile foundation restraint are compared and analyzed.3.Using ANSYS finite element software,the influence of soil load on the temperature effect and the difference of crack development of basement roof are compared and analyzed when considering pile foundation constraints.The analysis results show that the influence of overlying load on the stress distribution of roof is more obvious,and it has little effect on the crack development area.The stress concentration appears only in the lower left corner of the structure,and the stress distribution of the roof without overlying load is symmetrical with respect to the central axis.The crack locations of the two roofs appear in the lower left corner of the structure.4.Using ANSYS finite element software,the temperature effect and crack distribution of floor and side wall with or without pile foundation restraint are compared andanalyzed.The results show that the effect of pile foundation restraint on the over-length basement structure is very significant,and the stress distribution andcrack form of the two are quite different.Over-length basement concrete structure with pile foundation restraint,which joint of pile and floor(strong restraint area)will make the structure "from big to small,from long to short",each region has its own temperature effect and does not interfere with each other.5.According to the results of finite element analysis,the crack control principle and combined with the existing crack control measures technology,the crack control measures are put forward from three aspects of design,construction and material for this project.