Protecting New Orleans From Future Storm Devastation
Protecting New Orleans From Future Storm DevastationPutzmeister trailer pumps and placing booms play significant role in constructing historical surge barrier
STURTEVANT, WI (August 10, 2010) – In the aftermath of Hurricane Katrina in 2005, Putzmeister America, Inc. and its high performance trailer pumps and placing booms helped to piece back together the city of New Orleans.
During the hurricane, a powerful storm surge caused a 4,000-foot-long (1,219m) section of a floodwall to collapse and flood the city of New Orleans. As the nation watched in horror, a collective thought emerged: Could this level of devastation be prevented from happening again?
In 2006, after commissioning a study of the New Orleans levee system, Congress authorized a far-reaching initiative to protect the region from future storm damage. The colossal project, called the Inner Harbor Navigation Canal (IHNC) Surge Barrier Project, would involve constructing a surge barrier near the confluence of the Gulf Intracoastal Waterway (GIWW) and the Mississippi River Gulf Outlet (MRGO). The new surge barrier, which is similar to a floodwall but larger, will reduce the risk of flooding to some of the region’s most vulnerable areas. The U.S. Army Corps of Engineers and the Coastal Protection and Restoration Authority of Louisiana would be owners of the project. At a price tag of almost $700 million, it would be the Corps of Engineers’ largest design-build civil works project to date, and the world’s largest storm surge barrier. It would also be an ideal application for Putzmeister’s concrete trailer pumps and placing booms.
In addition to the countless complications that are inherent in a project of this magnitude, timing was to prove another challenge. As part of the Corps of Engineers’ Hurricane and Storm Damage Risk
Reduction System, the surge barrier project had an aggressive deadline of 2011 in order to provide 100-year-level storm protection to the city and surrounding areas. The clock was ticking before the project had even started.
Building a starting lineup
In April 2008, the Corps of Engineers awarded project management, design and construction to Shaw Environmental & Infrastructure (Shaw). Headquartered in Baton Rouge, Louisiana, Shaw would be responsible for constructing a 10,000-foot-long (3,048m), 26-foot-high (8m) barrier floodwall, a swing barge gate and sector gate on the Intracoastal Waterway, and a vertical lift gate at Bayou Bienvenue, as well as rock-enforced T-style floodwalls. Shaw in turn hired Seattle-based Manson Construction Company (Manson) to serve as the sub-contractor.
The massive project necessitated advanced measures, which began in October 2009. This initial work involved building a concrete barrier and a swinging navigational barge gate on the GIWW to allow boat and maritime traffic to bypass construction of the concrete floodwall – while also providing protection from surges. Additionally, temporary gate structures would need to be built at both the GIWW bypass swing gate and the Bayou Bienvenue lift gate to provide risk reduction until the sector gates could be completed. Finding the right manufacturer’s equipment to place concrete and pour the first tremie slab for the GIWW bypass gate would be first in order.
Complete systems approach wins bid
In May 2009, after analyzing the situation and conferring with the Corps of Engineers, Shaw and Manson, the Special Applications Business (SAB) group at Putzmeister America proposed a complete systems approach.
The proposal featured high-performance trailer pumps and placing booms, which could be placed on the edge of the barge. This would allow the placing booms to get much closer to the pour and achieve greater reach.
“We were able to show Manson the most economical and efficient way to place concrete,” explains Bill Carbeau, director of Putzmeister’s SAB group.
With a looming deadline, the sub-contractor chose the proposed solution for the complicated job. The final equipment list included two BSA 1409 trailer pumps and two placing booms: one MX 36/40Z placing boom with a horizontal reach of over 115 feet (35m), and one MX 34/38Z placing boom with a horizontal reach of 108 feet (33m). Each Series II Detach boom would be positioned on 30-foot (9m) freestanding pin tower, mounted via foundation base plates to a welded platform on the pump barge. The proposal also called for two Maxcrete mixers from Maxon Industries, Inc., a member of Putzmeister’s SAB and a Wisconsin-based manufacturer of concrete mixers.
“The real advantage we offered was the ability to eliminate a complete transportation barge ¬– which saved a lot of time,” offers Carbeau. “By using our stationary pumps and the Maxcrete hopper, they could unload a batch of concrete off the barge and then, while the pumps continued to pump, they could take the barge back to restock it with concrete – without interrupting workflow. They didn’t have to waste any time waiting for the concrete barge. And by using trailer pumps, the contractor would have full control of the equipment. They could avoid having to wait for a boom pump to be driven onto the barge. The stationary trailer pump was right there, ready any time they wanted to pour.”
Concrete crews work round the clock
The first big pour for the bypass gate was a tremie pour that began at 5 p.m. on Friday, October 23, 2009. The pour continued nonstop for the next 41 hours, finally ending at 10 a.m. on Sunday morning, October 25. During this initial pour, the trailer pumps and placing booms pumped and placed approximately 5,000 cubic yards (3,823m3) of concrete – without a hitch.
“The equipment performed very well,” notes Bob Edwards, Manson’s operations manager. “We worked 41 continuous hours and had absolutely no problems.”
A special self-leveling concrete mix which hardens to 4,000 psi within 48 hours, called Agilia®, was used for the tremie pour.
After the tremie pour was complete, the crew started a 4,000-psi pour for the pile cap. This was a 4,000-cubic-yard (3,058m3) concrete pour which was completed in four equal segments.
Despite the extra challenges of a complicated water project, such as lack of proximity to equipment and supplies, additional safety precautions, environmental issues, and armies of annoying Gulf Coast gnats, the first major phase of construction has remained on schedule.
The concrete pumping and placing equipment has played an important role in maintaining that schedule by performing as promised. With the highest pressures and outputs available, the two BSA 1409 trailer pumps provided reliable, high-capacity pumping that was crucial for meeting the deadlines of the time-sensitive project.
“We were able to pump up to 150 cubic yards (115m3) of concrete per hour,” explains Edwards, “That may not sound too fast, but it’s actually very fast when you realize the job is one mile (1.60km) – out in the water – from where the concrete trucks are loaded onto the barge, so being able to supply and pump that much concrete was important to us.”
The placing booms also delivered time- and space-saving advantages. Their low flyweight made setup easier, and allowed them to be positioned farther from the crane for overall placing coverage. Because the placing booms didn’t require counterweights, the crew was able to save space on the barge. And with Putzmeister’s exclusive Hydraulic Quick Disconnect and four-pin tower connection, the booms could be quickly and easily lifted onto the freestanding vertical pin towers.
“This system was very easy to assemble. After welding the bases onto the barge, both towers and booms were set up in one day,” states Edwards. “And since it was self-contained and powered, it was ready to go to work the same day.”
“The tower mount allowed the booms to reach over and into the cell from a high starting point,” says Edwards. “This made it easy to reach all our pours. When we first started, we were reaching over an eight-foot-high (2m) sheet wall and into a 23-foot-deep (7m) coffer cell. On our last pours, we are reaching over a 23-foot high (7m) abutment and guide wall to make our pours. The tower proved to be a good way to approach this work.”
Currently, the crew is working on a 5,000-psi pour for the abutment walls and guide walls to the bypass gate. So far, they’ve poured 1,300 (994m3) of the total 2,000-cubic-yards (1,529m3). Because this pour involves mass concrete sections thicker than six feet, the concrete has had to be chilled with liquid nitrogen to reduce its delivery temperature. “If the concrete were to get too hot, it wouldn’t reach its design strength,” explains Edwards. “Cooling the concrete’s delivery temperature prevents it from overheating while it cures.”
To date, approximately 10,300 cubic yards (7,875m3) of concrete have been placed. As of late May 2010, only some small pours for roadways and guide walls will be left. And if the rest of the project continues as smoothly, by the targeted 2011 hurricane season, New Orleans and the surrounding area will have a protective surge barrier as indestructible as the spirit of its people.
Technology that put you first
Owner/Developer: U.S. Army Corps of Engineers and Coastal Protection and Restoration Authority of Louisiana – New Orleans, Louisiana
Design Team: Ben C. Gerwick, Inc. – San Francisco, California
General Contractor and Concrete Pump
Supplier: Shaw Environmental & Infrastructure – Baton Rouge, Louisiana
Sub-Contractor: Manson Construction Company – Seattle, Washington
Concrete Ready Mix Supplier: Lafarge North American – Madison, Louisiana
Concrete Pump Sub-Contractor: SMECO – Kenner, Louisiana
Equipment: Two Putzmeister BSA 1409 H concrete trailer pumps; one Putzmeister MX 36/40Z placing boom; one Putzmeister MX 34/38Z placing boom; two Putzmeister freestanding pin towers; two Putzmeister foundation base plates; two Maxon 10-Cubic Yards Maxcrete Pugmill Mixers