Open AccessAnalysis and correction of stress error in construction monitoring of cantilever cast prestressed beam bridge
Author(s) -
Zhi shun Pan
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/780/2/022009
Subject(s) - creep , structural engineering , cantilever , prestressed concrete , superposition principle , stress (linguistics) , beam (structure) , span (engineering) , elastic modulus , shrinkage , materials science , engineering , mathematics , mathematical analysis , composite material , linguistics , philosophy
In order to correct the monitoring stress of long-span prestressed concrete girder more accurately, and consider the characteristics of bridge load gradually applied during cantilever construction, this paper proposes an accurate correction method for monitoring stress of long-span prestressed concrete bridge. Based on the linear creep theory and Bauer boltzmann (L.B oltzman) superposition principle, the invariant elastic mode of traditional calculation isreplaced by the equivalent elastic modulus from load-to-pre-calculation, and the formula of concrete creep, and the time-varying elastic mode is taken into account. The effect of concrete shrinkage and temperature change softer on the real stress value of the structure is accurately corrected by separating and removing stress-free strain from the measured strain. This method is applied to the calculation of the measured stress in the key section of the main beam of a long-span continuous beam of a high-speed railway. The results show that the modified stress value is in good agreement with the theoretical value and the error is significantly reduced, which verifies the reliability and accuracy of the modified method.