Bridge 1-420 is located on the Maryland/Delaware state line west of Townsend in New Castle County, Delaware. The project limits are approximately 200 feet North and 200 feet South from the center of the bridge.
Corrugated metal pipe culverts are corroding throughout the state. The Department has over 200 bridge-length corrugated metal pipe culvert locations, most of which are at or beyond their expected 30-year service life. This project is one location of the 28 locations included in the current Design-Build contract and it will help the Department meet its performance measures related to number of bridges in fair or poor condition.
The scope of the proposed project is to replace the existing corrugated aluminum pipes with two 84-inch diameter circular reinforced concrete pipes placed on the outer sides of a similar 96-inch diameter pipe. The proposed pipes are 40 feet in length with riprap protection installed at the culvert inlet and outlet openings, extending into the streambed at the upstream side. On the downstream side, a riprap toe wall is proposed. Pipe replacement will be performed under a full road closure with a posted detour.
Design work anticipated to be completed by Spring 2019.
Construction work anticipated to be completed by Summer 2019.
This pipe replacement is part of a larger Design-Build project consisting of multiple locations.