The Analysis Of Cracking Reasons In A Ultra-long Prestressed Concrete Frame Structure

The ultra-long reinforced concrete frame structure often cracks when it is applied by the external factors of loads, temperature changes, the basis of uneven settlement in the deformation and the internal factor of concrete shrinkage. So it is necessary for us to study the cause and affecting for crack in these structures.In this thesis the cause of crack in a parking floor which is a ultra-long concrete frame structure built in Beijing has been analyzed. And a reference is made to the crack test report and safety evaluation report for this building, then FEM analysis method is used to simulate the load on the structure and its response to discuss the cause of cracks occurred by all loads for this kind of structure. In the FEM analysis seasonal temperature, concrete shrinkage and vehicle load are applied to the FEM.On the basis of the work mentioned above,some crucial conclusions are acquired as follows. The FEM calculating result shows that the stress in seasonal temperature and concrete shrinkage is the primary cause of cracks in this parking floor, while the stress in vehicle loads cause the first floor of this parking floor cracking. It is doubltless that the work done in this paper is beneficial to the application of linear analysis in reinforced concrete frames,and that it has theoretic value to crack control of reinforced concrete super-long frames,and has benefit to enhance controlling level of cracks.