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Building a bridge across the marsh

 


Building a bridge across the salt marsh


To access oak hammock islands (technically: isolated uplands) we needed to span several hundred feet of slat marsh. The original plan was a typical pile supported bridge design however, soil borings in the marsh indicated minimal bearing capacity. The length of the pilings that would be needed made the project cost beyond the scope of the client’s budget. A brilliant plan was proposed by our project engineer, Dr. Michael Coffey, PHD, PE (at that time with Berryman & Henigar, Inc.), to create large ‘floating’ concrete pads for the bridge’s foundation. After obtaining the necessary ‘dredge & fill’ permits from DEP & COE, construction was set to commence. Our contractor was Johnny Holland, Holland Contractors, who brought a unique ‘can do’ philosophy to the project. Everyone was nervous: the client and development loan banker topped the list. Johnny finally told them: “I’m going to build the bridge and when I am done, you can run all your tests, but have my money ready!” With Johnny essentially taking all the risk, the project moved forward. In spite of some typical logistical hurdles, like getting the oversize bridge “T”s and heavy equipment through the dense oak canopy, construction proceeded smoothly. As the bridge neared completion, several tests were conducted to prove the bridge’s load bearing capacity. At a scheduled inspection, Johnny positioned a full concrete truck midway on the bridge. His only words: “Got my money?” The cosmetic finishes included: a stucco finish over the DOT rated guard rails and a nautical look with ‘old rope’ pulled through wooden posts. The bridges have now stood for over 20-years and show no signs of settling.

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