TRENCHLESS TECHNOLOGY PROJECT ON CITY ISLANDIN THE CITY OF NEW YORK

摘要

City Island is an old fishing community with an aging infrastructure located in New YorkrnCity's borough of The Bronx. The New York City Department of Design and Constructionrn(NYC DDC) was replacing 14,300 feet of 6", 8" and 12" diameter distribution water mainsrnthroughout City Island. In addition, the NYC DDC was replacing 8,500 feet of sanitary andrnstorm sewers ranging from 10" to 60" in diameter as well as 36 catch basins. The workrnencompassed 32 city blocks. City Island, in total, runs approximately 1-? miles long and ? milernwide and has one main avenue running north to south at its midpoint. This nautical town has arnvariety of boat yards, shops, and restaurants that are always bustling in the Spring and Summerrnmonths with tourists from all over the Northeast.rnThe City of New York (NYC) has the right of eminent domain over all city streets, whichrnrequired Con Edison's gas mains in direct interference with the new sewer and water mains hadrnto be moved. Con Edison had to relocate 5,000 feet of 2" and 4" diameter high-pressure (99 psirnMAOP) gas mains and 55 gas services ranging from ?" to 1" diameter. The new gas mains hadrnto be relocated to the sidewalk adjacent to 97 trees that could not be damaged in any way. Thusrnconventional open-trench excavation was out of the question. A special permit had to bernobtained from the New York City Parks Department and Con Edison had to guarantee the safetyrnof the root systems of these trees before work could begin.rnAfter careful study Con Edison decided to use a trenchless technology method calledrndirectional boring along with coiled polyethylene (PE) pipe to install the new gas mains. Thisrnmethod of installation minimized inconvenience to the City Island residents and tourists. It alsorneliminated the closing of traffic lanes, which would have been necessary with open cutting thernentire 5,000 feet for gas main installation. This trenchless technology was particularly effectivernin City Island since the soil was predominantly clay and contained minimal amounts of rock. ThernCity Island community was very satisfied with the results of this project. Trenchless technologyrnallowed shops and restaurants to thrive during their busy tourist season.