McCormick Taylor developed an innovative design solution to repair this major storm drainage culvert and extend its life to 100 years.



NJTA retained McCormick Taylor to complete final design for the repair of a corrugated metal plate arch culvert at risk of collapse at milepost 123.8 on the New Jersey Garden State Parkway (GSP).


The first indication of problems was a depression of the southbound outer roadway and shoulder. To investigate the cause of this depression, an inspection of the culvert extending under the roadway revealed that the CMP portion of the culvert exhibited signs of advanced and extensive deterioration.


Used by residents and out-of-state commuters traveling along the northeast corridor, the GSP is one of the most heavily traveled roadways in the state. The collapse and failure of the corrugated metal plate arch culvert would have affected tens of thousands of drivers daily. Furthermore, a collapse would block flow of Crossway Creek tributary in Sayreville Borough, resulting in flooding of upstream neighborhoods.

photo 4 temporary steel frame bracing which supported the culvert while the invert was being removed


McCormick Taylor served as the prime consultant and completed the final design, bid, and construction consultation services for repairs at milepost 123.8.


In coordination with our subconsultant, KMA Consulting Engineers, LLC, McCormick Taylor performed geotechnical investigations and developed an innovative solution that we used successfully several years earlier on twin culverts measuring 9 feet, 10 inches high and 14 feet, 2 inches wide at GSP MP 118.5. The repair procedure, taken from the tunneling industry, involves the use of steel ribs and steel-reinforced shotcrete. The overall deformity of the culvert, in addition to the specific areas of failure, resulted in constantly varying interior geometry. A 3-D laser survey was performed of the culvert to obtain exact interior dimensions for design of the steel ribs.


In addition to the geotechnical investigation, McCormick Taylor performed the required hydrology and hydraulic analyses to obtain Flood Hazard and Freshwater Wetland Permits; performed the structural design for the culvert lining; and prepared final design plans, specifications, and the construction cost estimate.

photo 5 steel ribs were used to rebuild a new culvert within the existing one
f photo 1 upstream view of 850 section of 10 x14 culvert after completion of work


The innovative design solution repaired this major storm drainage culvert and extended its life by 50 to 100 years. The culvert will continue to provide drainage of the creek, while ensuring safe operation in this heavily traveled area.



  • 2019 Merit Award - Shotcrete Category – New Jersey Concrete Awards
  • 2018 Project of the Year – ASHE NCNJ & SNJ
  • 2018 Distinguished Engineering Award – New Jersey Alliance for Action
  • 2017 Honor Award - Small Projects – ACECNJ's Engineering Excellence Awards