Research On The Seismic Behaviors Of Prestressed Concrete Frame

Based on comprehensive literature research , this dissertation carried out the model test include one non-prestressed concrete frame and two prestressed concrete frames under cyclicloads , and theoretic analysis of ten frames by using Push-over method.1. The quantity of cracks of non-prestressed frames are much more than those of prestressed frames. The situation of cracks closing of prestressed frames is much better than that of non-prestressed frames.2. The plumpness of the load and displacement loops of non-prestressed frames is much better than that of prestressed frames. The load and displacement loops of prestressed frames is more or less a little narrow. The stiffness changes slowly of both non-prestressed frames and prestressed frames at the elastic stage. The degeneration of stiffness of non-prestressed frames is much quickly than that of prestressed frames at the elastic-plastic stage. The stiffness of non-prestressed frames and prestressed frames is tend to be the same after the degeneration of stiffness at the plastic stage.3. The energy dissipation of prestressed frames is smaller than that of non-prestressed frames. And the increment of energy dissipation of prestressed frames is less quickly than that of non-prestressed frames. The degree of the increment of energy dissipation is slowing down at later period. And the degree of slowing down of prestressed frames is bigger than that of non-prestressed frames. The energy dissipation of prestressed frames increases after strengthening the column.4. The bottom of column of the ground floor especially the bottom of middle column is the weakest place. Because prestressed frames have their own characteristic, such as secondary internal force. The quantity of reinforcement of column of prestressed frames is smaller than those of non-prestressed frames. How to deal with these weakest place is more important to prestressed frames. Increasing the reinforcement of column can do some effect to delay the damage of column plastic hinge, but the effect is limited. The ability of rotation of column plastic hinge is getting worse after the increment of reinforcement of column. So we should pay a great attention to the structural treatment.5. The quantity of reinforcement of prestressed frames is small at the bottom part of beam-end. So the ability of rotation of hogging moment region is weak, and the bearing capacity of sagging moment region is small. It leads to the damage of hogging...