Seismic retrofitting techniques using an energy absorption segment for steel bridge piers

Importance has been attached to seismic design methods considering the ductility of steel structures after the Hyogo-ken Nambu Earthquake and one of the design methods is adopted into the design method of steel bridge piers in Japan. On the other hand, it is necessary to retrofit the existing steel bridge piers not satisfying the design standard and having inadequate ductility. This paper deals with seismic retrofitting techniques for the existing steel bridge piers to be retrofitted in cases where concrete filling technique is untenable. Instead of the concrete filling technique, proposed are two seismic retrofitting techniques installing a small part or a short segment, to which major plastic deformation is limited, in a column member of the steel bridge piers for enhancing the ductility capacity of the column member. The validity of the proposed techniques is investigated through a cyclic loading test and a pseudo-dynamic test. Various applications and variations of the techniques are also discussed.