Study On The Seismic Performance Of Partially Concrete-filled Steel Box Bridge Piers

Steel pier is of light weight, saving floor space and construction time, being strengthened easily, so it is more and more popular in developed countries such as American, Japan, and Germany.Steel box pier is a popular type in use. Unfortunately, there were a large parts of which destroyed because of local buckling in the Hyogo-ken Nanbu Earthquake of 1995. Many strengthening methods were presented, among which, partially concrete-filled strengthening method was the most popular one.The paper studied the seismic performance of steel box bridge pier and the strengthening effect of partially concrete-filled strengthening method using finite element method. The basic theory of finite element method, material model, and finite element model were introduced. Nonlinear buckling analysis was carried out to study the strength and ductility of piers, and the influence of factors such as relative slenderness ratio, width-to-thickness ratio and concrete strength was investigated. As a result, reasonable filled-concrete ratio should be 15% to 25%.Also, the seismic performance of partially concrete-filled steel box bridge piers under cyclic loading was investigated, it was found that the seismic performance of which was better than steel one, and partially concrete-filled strengthening method was effective.