U.S. Army Corps of Engineers
Digital Engineering provided engineering design for the construction of approximately 19,000 linear feet of a T-Wall floodwall barrier separating the Parishes of St. Charles and Jefferson. The new floodwall replaces an existing structure which consisted of bothT-Wall and I-Wall monoliths. One of the biggest design challenges was to maintain existing flood protection from the original wall during construction of the new floodwall. It was built only 20' to 30' away from the face of the existing wall. The design needed to carefully weave the H-piles for the new floodwall between reinforced concrete piles that were stabilizing the existing floodwall.
As Prime Firm, DE was responsible for the preparation of final plans and specifications, test pile program, right-of-way issues, and construction access drawings. The project also included the design of land-side subsurface drainage along the floodwalls.
Construction features included the construction of the T-Wall beneath the I-10 overpass and the accommodation of the 84 inch diameter discharge tubes from the Parish Line Pump Station through the new T-Wall monoliths. An additional design challenge was to accommodate a pile spacing which would not conflict with the existing battered piles which were spaced on 8foot centers.
The project was bid in two phases with a total construction cost of over $120 million. Both projects were completed in 2012. DE received an overall ACASS rating of “Very Good” for the project.The Rating Official remarked “The A-E produced a very good product under the tight duration and changing design criteria.”
In June 2013, this project was honored by Engineering NewsReward as a Global Best Project.