Research And Application Of The Constraint Problem Of Super Long Concrete Structure

With the increasing application of super long concrete structure engineering,how to control the generation of harmful temperature cracks in the construction and use of super long concrete structure under different constraint conditions is the current problem to be solved.In this paper,through a large number of engineering tests and theoretical analysis,the temperature difference value of different concrete structures,the constraint mechanism,the horizontal resistance coefficient of the foundation,the reasonable zone length of the structure under different temperature difference and constraint conditions are studied.The main works are as follows:(1)summarize the theory of shrinkage deformation and temperature stress of super long concrete structure,and analyze the relationship between constraints and shrinkage of super long concrete structure.Based on the statistics of relevant engineering data,this paper analyzes the structural measures of different foundation constraints,such as waterproof layer,sliding layer,cushion and anti floating anchor.(2)Based on the relevant temperature test data of different structures in Qingdao,the paper analyzes the change rule of temperature of floor,wall and upper structure with time,as well as the proportion of hydration heat temperature difference,equivalent temperature difference and long-term temperature difference in each time period.This paper analyzes the influence of the external environment on the temperature difference of concrete,and puts forward the ratio coefficient between the external environment temperature difference and the internal temperature difference of concrete,which paves the way for further research on the reasonable partition length of the structure under different temperature difference and different constraint conditions.(3)Through the dynamic characteristic test of the foundation and the temperature and strain monitoring test of the on-site floor,this paper studies the constraints of different structural forms,such as cushion,waterproof layer,sliding layer,anti floating anchor.According to the relevant test data,the horizontal resistance coefficient of the foundation under the corresponding constraint is calculated,and the reasonable partition length of theoverlong concrete floor under different temperature difference and constraint conditions is proposed.The finite element software is used to simulate and analyze the floor with or without anti floating anchor and different diameter anti floating anchor,and analyze the change rule of the influence of anti floating anchor on the floor restraint.(4)based on the measured test of the basement wall of a certain project,the change rule of the confined strain and temperature of the basement wall with time is analyzed.Using the data of temperature and strain to calculate the horizontal resistance coefficient of the wall foundation,and put forward the reasonable partition length of the wall under different temperature difference.This paper analyzes the causes of the cracks in the test wall,and puts forward the concrete ideas and measures to control the cracks in the wall.In this paper,the restraint mechanism of super long concrete structure under different restraint conditions is analyzed deeply and comprehensively,and the horizontal resistance coefficient of foundation and reasonable partition length of super long concrete structure under different restraint conditions are obtained,which provides more theoretical support for the construction of super long concrete structure,so as to realize more convenient and seamless construction.