Structural fuse concept for bridges

The concept of designing sacrificial elements to dissipate seismic energy while preserving the integrity of the structure's other main components is known as the structural fuse concept. Few implementations of this concept have been rigorous in emphasizing replaceability of the sacrificial elements and absence of damage to the primary load-resisting structural system. Here the concept is applied to an innovative multicolumn accelerated bridge construction (ABC) pier concept. Different types of structural fuses are investigated to compare the effect of each on ABC bridge bents. A three-span continuous bridge prototype having two twin-column pier bents with fixed base spaced at 36 m (120 ft) and 9 m (30 ft) tall was designed according to AASHTO load and resistance factor design specifications. Its piers were designed with double-composite rectangular columns using Bi-Steel panels and structural fuses. Two corresponding 2/3-scale models were developed and tested. The two specimens were designed for a maximum horizontal force of 1,777 kN (400 kips). Three quasi-static tests were performed. For the first specimen, steel plate shear links were installed between the columns as a series of structural fuses. Testing was performed up to a drift corresponding to the onset of column yielding to investigate the effectiveness of adding the fuses in dissipating the seismic energy, then testing continued until column failure. Then, the other specimen was installed and tested utilizing buckling restrained braces (BRBs) as a series of structural fuses. The BRBs were then removed and a bare frame cyclic test was performed until column failure.