Hyogo-ken Nambu Earthquake in 1995. Shear failure of two reinforced concrete main piers together with tensile fracture of reinforcing bars were observed. Earthquake response analysis to the overall bridge structure and static nonlinear finite element analysis to the main piers have been conducted to identify the reason and the process of those damages. Diagonal tension failure and shear failure of the main piers have been approximately presumed through the comparison of the analyzed results with the observed damage. Furthermore, the analytical techniques regarding discrete models of a caisson foundation and nonlinear rules of reinforced concrete members have been discussed with parametric studies.