Analysis On Temperature Stress Of Super-long Concrete Structure And Research On Its Control Technology

With the development of economic construction and building technique, the super-long concrete structures are built more and more in our country. These buildings usually have no or less expansion joint, which leads to the length of whole structure oversteps the value our country Coad prescribed. For the super-long structure, temperature stress is the important factor that have to be considered in design. So it is important to analyze the temperature stress and research its valid control technique of this structure.In the thesis, the elastic mechanics theory of temperature stress was introduced at first. Then give a presentation of the finite element theory of temperature stress and how to analyze super-long structure with ANSYS using 3D beam and shell element. As the concrete structures experience the function of variety of natural environment temperature and solar radiation etc., plus the concrete material worse heat exchange, the temperature field of the buildings is complicated. The structure reaction of some temperature loads is emphasized in this paper.The main study of this thesis includes five parts. Firstly, the super-long structure reaction under annual temperature load was analyzed, and parameter analysis to its influenced factor was done, of which the influence of shear wall was emphasized. Secondly, the structure reaction under instantaneous temperature load was analyzed. After the way to change nonlinear temperature field to its equivalent linear temperature field was introduced, the influence of temperature grads as to internal force and displacement of the structures was researched . Thirdly, the analysis of structure reaction under temperature load which considered beam temperature lag was taken out during which the concept of temperature lag stress was put forward. Fourthly, the effect of unbonded prestressed technique in controlling super-long structure temperature stress was analyzed, and the research of structure reaction under the function of linear unbonded prestressed tendons in some distribution was also taken, which results to prove that it is more reasonable to place prestressed tendons in floorslab strip under column which should be partly tensioned to reduce prestressing loss. Finally, temperature stress finite element analysis of an actual project was carried out using the temperature field from the site test of this structure, which indicated that the results from calculation was well consistent with the experimental results and it is feasible to analyze super-long concrete structures with ANSYS.