1.0 Introduction
The Kuala Kedah bridge was a conventional 12 spans simply supported bridge. Two of its piers were hit by barges causing extensive damages to the spun piles and bridge joints.12 numbers of piles were immediately strengthened by steel jacketing to restore the capacity of the bridge to cnable construction vehicles to move about during upgrading work to convert the middle 3 spans to an arch cable stay design.60 numbers of spun piles on the remaining piers were strengthened by jacketing to increase their capacity. The middle 2 piers were then demolished.
2.0 Design
MERBARAYA
The steel jacket is designed to strengthen to the top 3m of the spun piles by basically confining the concrete and additional steel reinforcement.
3.0 Method
All cracks found were epoxy injected. Honeycomb and spalled areas were patched up with polymer modified mortar.Galvanised steel plates of the required dimensions and thickness were secured to the affected member by anchor bolts. Holes were drilled into the steel plate for installation of injection ports. Non shrink grout was then injected into the gap between steel plate and concrete and allowed to set. The external surface of the steel plates were cleaned and coated with coal tar epoxy paint.