• Project consists of the design and reconstruction of a new bridge and roadway approximately 1 mile east of the US Route 4 and NH Route 108 intersection. Initial work involves geotechnical investigations, guardrail removal, and utility relocations and continues through construction of new bridge and approach road work.  

• Total $7.1 million “best value” design-build contract awarded for project.

• The Bunker Creek water levels are tidal with approximate mean high and low tides at El. 3.9 and -3.8 feet, respectively.  The 100-year storm surge is approximately El. 7.0 feet. 

• The proposed roadway width has been increased to 34 feet, with two 12-foot-wide travel lanes and 5-foot-wide shoulders on each side.  Additionally, the proposed centerline profile will increase elevations up to four feet above the existing roadway grade and the proposed shoulder widening will increase elevations up to 8 feet in height above the grade along the toe of the existing embankment slope.

• Underlying soils along this section of US Route 4 are miscellaneous fill, tidal marine deposits, marine deposits, and glacial till.  The soft tidal marine and marine deposits very in thickness, between a total of 40 – 100 feet.

• The design-build team selected UL-FGA to construct portions of the widened and raised embankments to mitigate anticipated settlements and stability issues.  A unique approach was employed to install UL-FGA installation within a tidal zone.