Since 2009, Collins, as a subconsultant, has performed the biennial routine structure inspections and required warranty item specific frequency inspections for several large coastal complex bridges owned by the South Carolina Department of Transportation (SCDOT) as part of an asset management program.
Collins’ teams inspected the following:
- Eighteen bridges composing the Arthur Ravenel Bridge System, over six miles of structures
- Four coastal bridges in Berkeley and Charleston Counties, over ten miles of structures
- Two Beaufort County bridges, over two miles of structures
The complex bridge types included multi-level interchanges, cable-stayed systems, prestressed concrete beam and tub girders, post-tensioned girders and deck, steel plate girders, flat slabs, and fracture critical members. All engineers performing inspections were NBIS-qualified bridge inspectors. Inspection techniques for the bridge systems were both visual and tactile. The required inspection effort for each bridge varied due to bridge level elements, accessibility, and warranty level components. The high-level approach and main spans were accessed using climbing techniques from the in-place tie-off bars attached to the steel girders and traveler system, and the steel box straddle bents were inspected using confined space entry techniques. Access also involved aerial lifts, bucket trucks, and under-bridge units (including boats).
Collins was responsible for scheduling, equipment rental, traffic control, and generating reports for each structure. A formal report for each structure was prepared which included the SCDOT Bridge Inspection Form, Bridge Element Group Textual Data, SCDOT Pontis BMS Data, significant findings, field sketches, and color photos.