Design Of Super-long Concrete Structure For A Project

With the rapid development of China’s economy and the continuous deepening of urban construction,there have been more large-scale public buildings and industrial buildings.Taking into account the needs of architectural functions and appearance,these buildings always have no or fewer expansion seams.The length of the structure without seams was far beyond the limits stipulated in our country’s codes.it was called a Super-long Concrete Structure.Due to the large number of vertical concrete members,the floor have been great restricted by the vertical members when the temperature of the structure changed,and the temperature effect of the structure is obvious.The opening of the floor often give rise to the local temperature stress redistribution of the floor.With the temperature of the whole building structure changed,the temperature effect of the Super-long Concrete Structure with different layers was different from that with the single layer.For multilayer Super-long Concrete Structure,temperature changed on different floors also affects other floors.In this paper,the finite element standard model was first established to calculate the temperature effect when the temperature changed,and the law of temperature effect about the standard model was obtained according to the analysis results.On this basis,it was analyzed that the effects of floor openings of different sizes on the temperature effect,the effects of different layers on the temperature effect,and the temperature effect of Super-long Concrete Structure when the temperature changed only at the top floor was analyzed.The effect of the post-pouring belt on the temperature effect of the Super-long Concrete Structure and the effect of the unbonded pre-stress on the temperature effect of the Super-long Concrete Structure,and the conclusion was drawn: After the floor opened,the stress concentration of the floor will occur,and with the size of the hole increased,the stress concentration was more serious,which lead to an increase in the amount of reinforcement on the floor;When the temperature of the whole building changed,the maximum temperature effect appeared on the top plate of the first layer.After the number of layers exceeded two layers,the effect of the number of layers on the temperature effect of the top plate of the first layer was not significant.When the top layer temperature changed only,the top layer temperature effect does not change with the number of layers.The lower layer of the top layer was most affected by the top layer temperature effect,and this effect does not change with the increase of the number of layers;The post-pouring belt in Super-long Concrete Structure can release a lot of floor tensile stress caused by the shrinkage of concrete,which greatly reduced the cost of anti-cracking measures for super long concrete structures.In the stage of structural design,it was analyzed that the most unfavorable temperature change conditions of the project,and the temperature effect of the structure during the temperature change of the whole building structure and the temperature change of the top floor structure only.And according to the analysis results,the economic comparison of different reinforcement modes were made with representative plate span,and the conclusion was drawn: the amount of steel bar and the total cost of steel bar were minimal.