Study On The System Reliability And The Life Prediction Of Continuous Rigid Frame Bridge

Continuous rigid frame bridge with its superior characteristics of bridge type, on thehighway, especially in the western mountains across the canyon highway has been morewidely used. Currently, we mainly use deterministic analysis methods, such as the finiteelement method, to analyze the class structure. However, there are many random factors in theactual project, need to study on the reliability level of continuous rigid frame bridge based onthe probability theory. With the growth of the bridge service time, due to the role of variouscorrosive media, the bridge structure which exposed to the external environment appearsphenomenon such as weakened durability and bearing capacity drops that greatly affected thenormal use of the structure. As a result, the bridge structure based on the theory of thetime-varying reliability life prediction has a great significance.First of all, this article starts from the reliability theory of structural elements of thebridge, then introduces resistance and load effect parameters of the continuous rigid framebridge, the reliability indexes of component parts are calculated by JC method and the specificprocess is realized by Matlab software according to the algorithm;. secondly, based on thefailure mechanism and the failure criteria of continuous rigid frame bridge, the dominatefailure modes for structure are hunt by the branch-unzipping method overall cases，the systemreliability index calculation process of the continuous rigid frame bridge is put forwardcombining the branch-unzipping method with the correlation; thirdly, according to the resultsof the bridge time-variant reliability theory and the target reliable indicator, analyzingdomestic and foreign relevant resistance attenuation models, the paper gives the continuousrigid frame bridge service life prediction process by the discrete time method, combining withthe system reliability index calculation method; finally, based on the above theoreticalanalysis, a continuous rigid frame bridge, a real bridge, is calculated the system reliability andpredicted its life, so as to verify the proposed method is reasonable in accordance with theproject instance..The paper focuses on problems of the calculation of reliability and its life prediction.Specifically, during the study, considering the correlation among main failure modes and theeffect of whole bridge, this paper puts forward the reasonable reliability calculation method,thus it can be generally grasp the system failure characteristics of long span continuous rigidframe, for the system reliability analysis method providing a more effective theory. Accordingto the time-varying reliability theory, learning from the resistance attenuation model and the corresponding reliability index, this article proposes the residual service life predictionprocess, which provides an effective analysis method.