James B. Edwards Bridge Explained

Bridge Name:Wando River Bridge
Website:https://wandobridge.com/
Official Name:James B. Edwards Bridge[1]
Crosses:Wando River
Locale:Charleston - Mount Pleasant, South Carolina
Maint:South Carolina Department of Transportation
Length:7,900 feet
Width:Twin 44feet wide bridges
Traffic:45,300[2]
Cost:$34 million[3]
Coordinates:32.8599°N -79.8966°W

The James B. Edwards Bridge, also referred to as the Wando River Bridge, is a pair of pre-cast post-tensioned concrete box girder bridges that span the Wando River between Mount Pleasant and Daniel Island on Interstate 526 (I-526) in South Carolina.

The bridge was designed by Figg Bridge Engineers and is owned and maintained by the South Carolina Department of Transportation. The bridge is named for James B. Edwards, who was a governor of South Carolina, Secretary of Energy, and long-time president of the Medical University of South Carolina.

Construction

The bridge was constructed of pre-cast concrete segments using top-down construction. Segments were transported along already completed spans and put in place from above. This construction method was selected to reduce construction impacts on the marsh areas along the banks of the Wando River.[4] The bridge is designed and built to accommodate six lanes of traffic with narrow shoulders, and has been used for four since opening. The construction contractor was T.L. James Associates of Louisiana.[5]

The bridge has a history of issues that arose during or from the construction. Allegations about the workmanship led to a year-long investigation which found no issues. The construction contract ended in countersuits with the SCDOT suing for delays and the contractor suing for design deficiencies. This resulted in a $4.9 million settlement paid to the contractor. Aluminum expansion joints installed on the bridge failed within four years, which required SCDOT to install replacements at a cost of $2 million. And the profile of the bridge deck would cause discomfort (vertical pitching of motorists).[6] [7]

2018 Post-tensioning failure

A failure of post-tensioning cables, which are inside the box girder of the bridge, caused a closure of the westbound spans mid-day on May 14, 2018. Weekly inspections of the 92 cables inside the bridge had been occurring since a repair project in 2016.[8] On Sunday May 20, 2018 the eastbound lanes were altered to allow two-way traffic while repairs to the westbound side take place. The westbound span reopened to traffic on June 2, 2018.[9] A 2800-page November 28, 2018 engineering report provided fourteen recommendations which will be implemented to ensure the bridge meets its design life of 75 years. The recommendations include the installation of redundant post-tensioning cables.[10]

Notes and References

  1. http://www.scstatehouse.net/sess110_1993-1994/bills/1170.htm Concurrent Resolution
  2. http://www.scdot.org/getting/pdfs/Traffic_Count_Files/Charleston05.pdf SCDOT Traffic Counts
  3. Web site: FIGG James Burrow Edwards Bridge . 2014-08-01 . 2015-02-15 . https://web.archive.org/web/20150215004555/http://www.figgbridge.com/james_edwards_bridge.html . dead .
  4. Kohls, Amy R. and D. Brice Urquhart, Design Challenges and Construction Benefits of Precast Segmental Rail Bridges, Accessed April 20, 2007.
  5. Web site: Wando Bridge designer: 1 broken cable would not make bridge unsafe for driving. Tripp. Drew. May 16, 2018. abcnews4.com. WCIV. Charleston, SC. https://web.archive.org/web/20180707213248/https://abcnews4.com/news/local/wando-bridge-designer-1-broken-cable-would-not-make-bridge-unsafe-for-driving. July 7, 2018. July 7, 2018.
  6. Web site: Renowned firm that designed Wando River bridge has ties to previous span collapses. Smith. Clenn. Behre. Robert. Berry Hawes. Jennifer. May 15, 2018. postandcourier.com. The Post and Courier, Inc.. Charleston, SC. https://web.archive.org/web/20180707220005/https://www.postandcourier.com/news/renowned-firm-that-designed-wando-river-bridge-has-ties-to/article_d6af64de-5862-11e8-b63f-1b5627d2b97c.html. July 7, 2018. July 7, 2018.
  7. Web site: Four-year-old bridge to get costly repairs. Bartelme. Tony. February 28, 1995. postandcourier.com. The Post and Courier, Inc.. Charleston, SC. https://web.archive.org/web/20180707220542/https://www.postandcourier.com/news/wando-river-bridge-had-unusual-repairs-as-a-new-bridge/article_bfbb55e2-584b-11e8-a5ec-bfd01decf887.html. July 7, 2018. July 7, 2018.
  8. Knapp, Andrew and Jackson, Angie, May 14, 2018. Broken cable in Wando River bridge closes westbound I-526 for at least 2 days . Post & Courier. Charleston, SC. Archived version
  9. Web site: Wando River bridge expected to reopen Saturday. Knapp. Andrew. May 31, 2018. postandcourier.com. The Post and Courier, Inc.. Charleston, SC. July 7, 2018.
  10. Web site: Yearlong repairs planned to improve longevity of troubled Wando River bridge. Yee. Gregory. Jackson. Angie. January 25, 2019. postandcourier.com. The Post and Courier, Inc.. Charleston, SC. February 2, 2019.