Abstract:

The  failure mode of concrete beams is analyzed based on the theory of security systems engineering and finite element  method  basic principle  to ensure the structural concrete  beams  reinforced security and reliability，understand concrete beams strengthened in various environmental stress load conditions  to  a reinforce concrete beam. Failure tree model and finite element model of reinforced failure of concrete beams  as  the  top  event were established. Queltative analysis and numerical calculation were done. so as  to  make  the overall evaluation of the structural safety of reinforced concrete directly, and determine the main  potential risk of accident.  Further more，reliable analysis of reinforced concrete beam strengthened sevurity was done. The research results show that the mode failure probability is about 2. 13 % in concrete beams reinforced concrete beam failure，building concrete beam reliability is about97. 87 %. It can provide a scientific basis for the determination and implementation of concrete beam reinforcement methods.

Key words: concrete beam reinforcement, finite element method, fault tree model, structural safety, reliability analysis