Project DetailsLocation: Port Republic & Tuckerton, New Jersey
Owner: New Jersey Department of Transportation
Contractor: Agate Construction Co., Inc.; New Jersey Highway Supply
Mullica River (2012) and Bass River (2014) bridges on the Garden State Parkway in southern New Jersey were constructed in a brackish marine environment on extremely soft foundation soil. The most efficient design for the embankments and abutments proved to be MSE walls with a sophisticated ground improvement design provided by Menard Group USA. The ground improvement involved installing Controlled Modulus Columns (CMC) with a load transfer platform on top, which provided the strength needed to build the high MSE embankment without yielding high settlement. The Bass River MSE walls were instrumented in order to study the effects of the foundation design in relation to any localized added tension in the lower soil reinforcements.
The site criteria included a flood elevation of 9 feet, which would potentially submerge about half the height of the tallest sections of the retaining walls. To account for the brackish water potentially corroding the soil reinforcements at a higher rate than normal, the MSE walls were constructed using a combination of RECo’s Retained Earth® system below the flood elevation, and Reinforced Earth® system above. The Retained Earth wall system uses wide ladder soil reinforcement, which in this case were made of stainless steel to provide additional corrosion protection. Galvanized ribbed soil reinforcing strips were used above the flood elevation.