Abstract：
Defects are caused on individual frame beams of a wide-span prestressed concrete structure due to lack of prestressed reinforcement, and local dismantlement and strengthening techniques are adopted after discussion and verification. After analysis on reliability stress, temporary support is set for beam slabs around the beam to be dismantled, mechanical cutting and manual chiseling are adopted to dismantle the defective beam, and then local replacement of component is carried out to strengthen the structure and to satisfy the requirements for structural safety and endurability.
