Study On Reasonable Structure Form Of The Super-high Pier Of Long Span Continuous Rigid Frame Bridge

The road network coverage is becoming big with the rapid development of the western transportation undertakings. Prestressed concrete continuous rigid frame bridge has become the main form of the western mountains highway construction across its large capacity,good overall performance,reasonable force,convenient construction,etc. Restrictions on the special terrain,the high pier and super-high pier was used to across canyons and rivers.When the pier height of the continuous rigid frame bridge is more than one hundred meters,different forms of pier structure has a great influence on the force and cost of the bridge structure.The engineering background of the dissertation is Guizhou Province Flyover Bridge①The dissertation Summarized domestic and foreign common piers form of the continuous rigid frame bridge,introduced the methods commonly used in high pier stability analysis,such as balance method、energy method、FEM.②Using the Rayleigh-Ritz method to derivat the in-surface and out-surface stable formula of the combined pier.In order to verify the accuracy of the formula, the dissertation compared with finite element results.③The dissertation study on the combined pier,research on the demarcation point position of the combined pier,got the conclusion that the demarcation point position is not combined with the high degree of combined Pier but combined with the section properties, the section properties of pier has a significant impact on the demarcation point position. The calculation method of the reasonable demarcation point position was proposed by the formula. The reasonable cutoff point position can be more convenient to calculate by graphic method.④The dissertation analysis the main factors affecting the stability of the super-high pier,including pier height,cross-sectional form,vertical piers,temperature gradient.Analysis shows that the stability of pier was sharp decline with the height increases, Section type also has a great influence on stability.The pier verticality and temperature gradient also reduce the stability of piers.