Utility Contractor

MAY-JUN 2018

As the official magazine of NUCA, Utility Contractor presents the latest information affecting every aspect of the utility construction industry, including technological advancements, safety issues, legislative developments and instructional advice.

Issue link: http://digital.utilitycontractoronline.com/i/976710

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Page 42 of 51

May/June 2018 | Utility Contractor 43 atees migrating to the river beginning in the fall, the project needed to be completed in the summer to avoid impacts. Petticoat Schmitt of Jacksonville, Florida, was awarded the $1.7 million project and mobilized to the site in January 2017. Challenges and Innovative Solutions The new 42-in. line was to be installed along an existing sheet pile wall, which is installed approximately 100 ft off- shore in the St. John's River, thus surrounded by water. Con- veying materials, including 40-ft lengths of large diameter pip- ing, to that area presented considerable logistical challenges. The reach from a barge mounted crane, floated in via the river, was determined to be too far for the weight of the mate- rials; meaning the size of crane typically on barges may not be able to handle the loads at the required distance. Also, Petti- coat Schmitt initially determined that conveying material from shore could not be accomplished because of a high power electrical line parallel to the work, and unknown utilities and structures underground that could be damaged by the crane's bearing pressure. After study and discussion with its crane subcontractor, Beyel Bros., Petticoat Schmitt decided to locate the crane on shore but closer to the water. This alleviated the potential haz- ard from an existing power line. Also, Petticoat Schmitt surveyed the underground utilities and structures using ground penetrating radar (GPR) in order to position the crane so that it did not cause damage. Lastly, as an additional safeguard, Petticoat Schmitt used crane mat- ting to distribute the load across a broader area. Utilizing these strategies, and relying on expert crane operators, mitigated the logistics challenge. Safely conveying crew to the area, and providing safe work- ing conditions while there, presented an access challenge. The solution to this problem ended up being simple, but imple- mentation was not. Petticoat Schmitt hired a scaffolding sub- contractor, Safway, to erect a work platform along the entire 720-ft length, providing room along the top of the sheet pile wall for crew members to receive materials and install them. Following the installation of the new pipe, Petticoat Schmitt faced further challenges in the demolition of the old pipe. Demolition needed to be done from a working barge, which could only be floated to the work site during low tide due to existing structures at the plant. Additionally, crab traps are common in the area and needed to be avoided. Petticoat Schmitt finished the project in June 2017 to the satisfaction of the owner. "With all of the difficulties on this project, the key really came down to proper planning," said Aaron Browning, project manager for Petticoat Schmitt. "We used GPR to identify any potential utilities in the area. In ad- dition, we surveyed the entire wall and then designed our pipe run based on the survey to make sure that there were no hiccups. Fortunately, the project went well with few hiccups along the way." New pipe sections are loaded from the land-based barge to the scaffold work deck. Scaffolding provided a safe working area for the crew. An aerial of the work site following installation of the new pipe.

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