45
www.read-wca.comWire & Cable ASIA – January/February 2014
From the Americas
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
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
BigStockPhoto.com Photographer: Aispl