The Reliability Analysis Of Reinforced Concrete Beam Before And After Reinforcement Of Increasing Cross-section Method

From the history of our country’s engineering construction, many structures have appeareddifferent degrees of problems in the process of using, which affected the structural safety,applicability and durability seriously. In order to ensure the security of people’s life and property,it is necessary to evaluate and test the reliability and safety of the part of the structures.Strengthen and reinforce structures and ensure the rapid development of social economy. Thereare only a few force analysis researches of the increased section method used to reinforcereinforced concrete, and most are once mechanical process. It is particularly important toconsider the mechanical properties of reinforced structure about the secondary stress. Theexisting reinforcement method proceeded from the practical experience of projects and didn’testablish a complete calculation method of the reinforcement. So, researching reinforcementtheory and analyzing the reinforcement technology has the realistic theoretical significance andapplication value.This paper introduces the basic theory of the increased section method, the influence ofreinforcement effect resulted from the strain hysteresis effect in the combination of the old andnew concrete. The flat sections of existing structures are analyzed and the effect of utilization ofsteel after strengthening caused by the stress level before reinforcement. This paper analyzes theeffect factors of the structural reliability after strengthening and compares the differencesbetween the reinforced structures and proposed structures. Based on the theory of reliability, thispaper calculates the reliability index of concrete beam that reinforced by increased sectionmethod with an engineering example and contrastively analyzes the influencing factors of thereliability index about structures before and after reinforcement. Factors that affect the structuralreinforcement reliability were analyzed in engineering practice. Based on the current lack oftress analysis of structural reinforcement, this paper analyzed the effect of stress level andproposed a new formula to calculate the stress of reinforced. This formula can reflect the stress level before reinforcement impact on the utilization of steel bar. The structural reliabilitycalculation method of reinforcement was deduced and the reliability index before and afterreinforcement, under the different influencing factors, were obtained. It discussed the factors onthe impact of structure after reinforcement. All those put forward guideline for the reinforcementin practical engineering.