KY 3 – Fly-over Ramp
- Project Owner: Kentucky Transportation Cabinet
- Location: Martin County, KY
Prior to this project, northbound traffic on KY 3 near Inez was required to stop at the T-intersection with KY 645 before turning left onto KY 645 to continue northbound. This condition was particularly inefficient for the high percentage of heavy trucks utilizing this route. The solution to this problem was construction of a curved ramp over KY 645 serving northbound KY 3 traffic and enabling a non-stop merge condition with northbound KY 645. J.M. Crawford & Associates provided preliminary structure design for this project as structural subconsultant to the prime roadway consultant and provided final structure design through the 2006 Statewide Structure Design contract.
The bridge is a 5-span hybrid structure consisting of a 3-span, 225’-162’-132’ continuous curved welded steel I-girder unit and a 2-span 104’-104’ prestressed concrete I-beam unit. The 3-span steel unit is in a 400’ radius curve and the 2-span PCIB unit is in a tangent alignment. The bridge deck is 28’ wide, supported by three girder lines and accommodates a single 15’ ramp, shoulders and barriers. Both abutments are founded on spread footings on rock with Abutment #1 requiring long wings and multiple footing steps. All four piers are single column “hammerhead” structures with three of the four on point bearing piles and the fourth on spread footings on rock. All substructures are oriented radial/perpendicular to the bridge centerline.
Final structure plans included an erection
plan outlining a scheme and sequence for erecting the curved girder sections
utilizing temporary shoring. This erection plan involved a non-linear staged
construction analysis of the girders to evaluate the structure throughout the
various phases of assembly as each segment is erected. Also included in the
scope of services was the checking of all shop plans for the curved steel girders
and prestressed concrete beams. The construction cost for this bridge was $3,813,479.