Characteristics Of Mountain Highway High Pier Bridge Piers Power Of Variable Cross-section

The paper studies and explores natural frequency of tapered high pier, combining with Liziping Bridge. First, the paper discussed effection on bound stiffness of bridge pier from three different foundation -expanding shallow foundation, the pile foundation and well foundation.Then formula, which is in four different bridge pier foundation without restraint on the top of pier and without axial force and axial force , is derived through assuming that the bending vibration shape function and using Rayleigh energy method. The paper also discussed how to simulate coupling spring in the finite element. By assuming the bending vibration shape function and shear vibration shape function, and using the Rayleigh-Ritz method, Southwell frequency composition method and Langrange equation, frequency approximate formula of tapered high pier in different types of constraints based on piers and the axial force, had been derivated from the vibration. By studying the frequency approximate formula for parametric analysis, the following conclusions were obtained.1)The vibration frequency results which is using power series as function of bending vibration were larger than those using the trigonometric function, but the difference between them was small, and the results were closer to the finite element analysis results when using trigonometry ; meanwhile, the results in untapered pier were closer to the finite element analysis results in tapered pier.2) For pier with elastic constraint at the top of the pier, effection of coupled stiffness to vibration frequency, could be neglected.3)Greater constrain rigidity, greater frequency of vibration; increasing of axis force, would lead to the smaller natural frequency;At last,the central working in this paper were summarized,the substantive conclusion were arranged and the working which have not been totally accomplished were prospected.