摘要

In order to calculate hydrodynamic pressure of piers with arbitrary cross-sections under earthquake, a new added mass method is presented. To accomplish this, the relation between fundamental frequency reduction rate and the ratio of added mass to structural mass per unit length is deduced. The relation is validated by using added mass from Morison equation. The fundamental frequency reduction rates of arbitrary section piers are available by utilizing the fluid element method in ANSYS, added masses of any piers are achieved according to the relation. Based on added mass data, the expressions of which can be proposed by curve fitting. The added mass expressions for two kinds of piers, circular and square, are suggested and compared with other two methods. Results show that the new method is accurate in both dynamic property calculation and harmonic response calculation. Practical application reveals that the new method is an accurate, efficient and adaptable way to evaluate hydrodynamic pressure under earthquake.