Probabilistic Method For Predicting The Resistance Of Existing Reinforced Concrete Flexural Members Based On Non-destructive Tests

The inference of component resistance is an important part of the existing structural reliability assessment.However,the commonly used indirect inference methods tend to be conservative due to the need to take into account the effects of many uncertainties,which may lead to unnecessary reinforcement measures.The internationally proposed test-based inference method is based on destructive tests with limited scope of application.Therefore,it is important and necessary to study the method of inferring the resistance of existing structural members based on nondestructive tests to promote the development of reliability assessment methods for existing structures.And the primary task of establishing such inference methods is to establish a probabilistic method for predicting the resistance of a single structural member which is based on non-destructive test.This dissertation focuses on the development of reliability assessment methods for existing structures.With the existing reinforced concrete bending members as objects,the paper studied the probabilistic prediction method for the resistance of individual existing structural members based on non-destructive tests.The main contents are as follows: A random process probabilistic model for the bearing behavior of the existing reinforced concrete flexural members was established by using the height of the crosssection relative to the compression zone as a parameter,and which revealed the probability relationship between the actual resistance of the components in the resistance and non-destructive tests of the components.The paper proposed a method for determining the height of the section relative to the compression zone with the results of non-destructive test,and a prediction method for the resistance of the existing reinforced concrete flexural members based on non-destructive tests was established.The proposed method is verified by the component test,and which also compared with the current indirect inference method.The results show that the stochastic process probabilistic model for the bearing behavior of reinforced concrete flexural members proposed in this paper can reasonably reflect the variation of the probabilistic characteristics of the load-bearing performance of the members with the relative height of the cross-section.The probability prediction method for the resistance of existing reinforced concrete flexural members based on non-destructive tests is reasonable and reliable,which is superior to the current indirect inference methods based on the test results of material properties and geometric dimensions.The research results of the thesis lay an important foundation for the ultimate establishment of the probability inference method for the resistance of existing reinforced concrete flexural members based on non-destructive tests.It also forms a system with both the current indirect inference methods and the inferential methods based on destructive tests.The dissertation also lays a foundation for the inferred method of the existing structural components of the system together with the current indirect inference method and the inferred method based on the destructive test,and provides more suitable conditions for the application of the experimental technology in the inference of the existing structural component's resistance.