Resistance Predicting And Verifing Of Existing Reinforce Concrete Member

Accurately inferring to current resistance of existing structures is an important premise for structure reliability assessment. Although the resistance of existing structure is not essencially different from the structure in design, the existing structures is already a spatial entity, and objectively the resistance is completely definite, constrainted by methods, information resources, knowledge and environment, the people's understanding of the existing structure resistance is subjectively uncertain.so the inferring method of the structure resistance in design isn't reasonable with existing structure.The article presents that the current resistance of existing structure is modeled by uncertained quatity, then analyzes the uncertained quatity and random variable in the contrast of concept and measuring method, and points out that the resistance function of the existing structure can be measured by the probability of random variable. Then the article puts forward the influence factors of objective uncertainty of the structures in design and subjective uncertainty of the existing structuers, and establishes the inference of reinforce concrete resistance which is pressed, bent and sheared in the condition of test and no test of geometric dates and material properties. The former considers the objective uncertainty of geometric dates, material properties and calculation mode; The latter also considers the measurement uncertainty of the rebound method.Quoting from the engineering example, the resistance inferrence of normal section and inclined section of reinforced concrete can be verified, then indicates:when the geometric dates and material properties are not tested, the results are bigger than the actual value of resistance, which are lack of the actual situation; when the geometric dates and material properties are tested, the results are fit for the actual value of resistance, the method is more reasonable to apply.The inferring method of existing reinforced concrete resistance in this article does not only overcame the constraint of the amount of samples, but also consider influence factors of subjective uncertainty of resistance, which can provide some references for the development of structure reliaibility identification.