Ultra High Pier Effect Analysis Of 185m High Pier And Long-span Rigid Frame Bridge In The Cantilever Construction

In cantilever construction of the large cross T structure, 185 m super high pier is especially flexible. At a temperature and other factors imbalance, pier prones to the longitudinal deflection, than resulting happen "seesaw" deformed, followed by increased structural stability decreases, and so bring ultra-high pier effect continued to enlarge. Therefore, it’s necessary to explore the construction of ultra-high cantilever pier effects with the pratie, and accumulate more experience in the theory and practice of such ultra-high pier construction.This paper combines 14# Sanshui river bridge pier height of 185 m super high pier cantilever construction of large span T. First, according to the theory of nonlinear analysis, the static and stability features for ultra-high piers T structure cantilever is analyzed with elastic, geometric nonlinear and material nonlinear analysis method, than research the stability of high pier with different pier height and form of three kinds of pier. Secondly, according to the long-term on-site 24 hours a day temperature observations and temperature observation pier shaft section summarizes the temperature variation. Further analysis of the equal and opposite effect of temperature gradients occur within boom segments at different step after the final effect, see if it can be fully restored to normal state. Finally, the actual site cantilever construction monitoring of elevation error sources, attributed to the ultra- Span T structure cantilever pier construction unbalanced effect factors, analyze load deviation, prestressed, not simultaneous construction, program changes and hanging drop basket case brought by the ultra-high mound effect, and gives some practical advice and appropriate preventive measures.After analysis, the structure must be considered for ultra-high pier geometric and material nonlinearity, especially geometric nonlinearity on the proportion of ultra-high pier deviation of about 15%; It’s recommend that pier height over 120 m pier is defined as ultra-high pier, which has a significantly higher pier effect; The optimal choice of the pier itself does not specify the form of choice, depending on the focus of the bridge structure to consider focusing selection; Under the sunlight changes, the maximum ambient temperature, the temperature of the inside of the thin-walled not the lowest, the lowest temperature occurs in the middle of the wall thickness of the basic position,showing non-linear relationship; During the construction cantilever end elevation error analysis, high piers T structure under the temperature response of the displacement in about 2cm, rest more errors generated by the unbalanced role; Different segments of the same block of consecutive positive and negative temperature effect of the construction process and appear unbalanced negative effect, the results will not be fully offset by cuts only part; Dropping the construction Cradle dynamic range effect exists, high pier and cantilever strength can meet, excessive deformation, it is necessary to avoid this situation. In short, accumulating more super high pier construction practical is necessary to rich analysis of ultra-high pier effect theory.