WCA January 2014

From the Americas

as a backstop to the Army Corps plan for a widened beach and continuous dune. But early estimates came in at around $40 million – for a structure half the length of the steel wall – and the Army Corps would not pay for it. “Those rock structures tend to be pretty expensive,” said Jon Miller, a research associate professor of ocean engineering at the Stevens Institute of Technology, in Hoboken. “Steel sheet pile is like a no-muss, no-fuss, just- drive-it-into-the-sand solution.”  Installation of the steel wall was expected to begin by the New Year, but Mr Moore noted that, until the beach-replenishment project comes in, the wall will be “only a couple hundred feet from the surf.” And coastal geologists and engineers told him that such hard structures need substantial amounts of sand in front as a shock absorber: to handle not just once-in-a-century hurricanes but also routine winter gales off the North Atlantic. Mr Moore wrote: “If the beach erodes too fast, waves hitting sea walls will increase their rate of scour — like concrete saws, eating out the sand at the base of the wall, washing it away, and relentlessly battering the structure.” That energy then bounces back and increases the rate of erosion, said Tom Ford, director of marine operations for the Santa Monica Bay Restoration Commission in Los Angeles. According to Mr Ford that has been well documented in Southern California, an urban coast, he noted, on which “we have a lot of coastal armouring.”  Indeed, the New Jersey project has drawn many sceptics and outright detractors. “This is a situation asking for trouble,” said Mark Mauriello, New Jersey’s longtime chief of the coastal division in the Department of Environmental Protection, now in retirement. “When that beach erodes and that wall is exposed, there will be trouble.” One of the softer voices among the commentators on the steel wall is that of Mr Young, of South Carolina, the expert on developed shorelines whose mild caution opened this piece. As he told Mr Moore: “Once you start building structures like that, you’re committed to beach replenishment — relentlessly pushing more sand in front of it.”  The Asbury Park Press did not allude to the painful awakening by residents of communities on both American coasts to the fact that they have much in common with people who live on the slopes of volcanoes. There was no need. Also implicit in the article was the prominence of steel — strong, corrosion- resistant, adaptable — whenever large natural disasters call for inventive responses. The US auto industry has Severstal’s Dearborn steel mill running flat out, but global pricing pressure erodes profits “I think we are at our peak demand, ever,” Saikat Dey, CEO of Severstal North America, told the Detroit Free Press

Steel A year later, a New Jersey coastal community ravaged by Superstorm Sandy looks to an old material for help “Does it hurt to put a sea wall up if the beach is already artificial? Maybe not. I understand…they were never going to let that inlet stay open. (But) over time these islands are going to be more at risk, no matter what we do.” This bleak assessment by Robert S Young, director of the Program for the Study of Developed Shorelines at Western Carolina University, was prompted by an expensive engineering project slated for the beach towns of Mantoloking and Brick in Ocean County, New Jersey, one of the states hardest-hit by Hurricane Sandy in November 2011. At a cost of $40 million, the Federal Highway Administration is offering New Jersey protection for the $260 million reconstruction of Route 35, where Hurricane Sandy punched a new ocean inlet through Mantoloking and across the highway. The cost is to be split: $32 million from Washington, $8 million from the state. Writing in the local newspaper, Asbury Park Press , Kirk Moore described plans for a vertical steel bulwark four miles long but mostly invisible under a continuous sand dune at the back of the beach. This “buried Iron Curtain” would be a last line of defence for the rebuilt stretch of roadbed. The wall is also seen as providing protection to the thinnest, most vulnerable stretch of a barrier-beach peninsula where charts dating to the 1700s show an inlet in almost the same place as the 2012 incursion. Larry Hajna, a spokesman for the New Jersey Department of Environmental Protection, said: “You don’t want history to repeat itself.” (“$40 Million Steel Curtain Proposed to Protect New Jersey Shore Highway,” 27 th September). Steel vs stone As explained by Mr Moore, the proposed structure would be a much longer version of the steel wall installed by the Army Corps of Engineers when it was suturing Mantoloking back together last fall. The steel panels – “sheet piles” – would be driven to a depth of 32 feet below sea level, with their tops 16 feet above sea level. At its location 500 to 600 feet east of Route 35 and in front of the houses on the oceanfront, the steel would be embedded in beach berms and dunes that are around ten feet above sea level now, said Robert Mainberger, Mantoloking’s engineer. That would leave about six feet of steel wall that Mantoloking and Brick would need to keep covered with sand, presumably until the Army Corps moves in with its planned beach replenishment: a much higher and thicker engineered beach and dune, to a height of 22 feet above sea level. Many Mantoloking residents would have preferred an extension of a neighbouring community’s stone revetment

BigStockPhoto.com Photographer: Aispl

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Wire & Cable ASIA – January/February 2014