Sealevel Construction, Inc.

Sealevel Construction, Inc. is a heavy civil contractor that was founded in 1997 by its president, Richard Roth, in the small town of Thibodaux, La. Starting with one employee and a toolbelt, Sealevel has evolved into a premier heavy civil contractor that self-performs services including deep foundations, structural fabrication, structural concrete, earthwork and sitework development with an emphasis on projects with driven piles. Reaching its 22nd anniversary this August, Sealevel has developed a reputation for its eagerness to take on unique challenges and to perform with integrity and safety as top priorities.
With a constant reminder from its founder to "always think long-term," Sealevel has expanded its capabilities to truly self-perform all aspects of heavy civil projects. While its self-sufficiency gives Sealevel a competitive advantage, it also adds value for its customers and engineers. Driven by this vision of thinking long-term, Sealevel strives to create and maintain relationships by completing each job with client satisfaction. The company's goal is to work with integrity, innovation and safe performance. These qualities are found within the company environment and have led to its growth and success.
Sealevel has completed many pile driving jobs in the Gulf Coast region. Most notable are two flood protection projects in Larose, La. that included a total of approximately 6,000 linear feet of steel sheet pile floodwalls. Also, Sealevel recently completed a 1,000 linear foot bulkhead in Port Fourchon, La., that included sheet piles up to 77 feet long and concrete deadmen supported by battered concrete piles.
As a versatile deep foundation contractor, Sealevel has also completed many pile driving projects in the industrial market, including a project at an LNG facility where concrete piles were installed up to 110 feet long in one piece. Furthermore, Sealevel has recently concluded the Falgout Canal Flood Control Structure for the Terrebonne Levee and Conservation District in South Louisiana. This job involved successful installation of steel pipe piles up to 84 inches in diameter and over 200 feet long, steel sheet piles over 80 feet long and fabricated jackets weighing 200 tons.
Sealevel's 60-acre facility complements its driven pile work with cutting and fabrication capabilities, including steel and aluminum fabrication, sand blasting, painting, CNC oxyfuel cutting, CNC plasma cutting and a variety of other services. Sealevel also operates a waterfront yard in Houma, La. that offers fabrication and repair services for the marine transportation and construction industries.
With a fleet of cranes up to 300 tons in size, over 30 excavators, air hammers, hydraulic hammers and vibratory hammers, Sealevel has invested heavily into pile driving equipment to better serve its clients and to stay true to its self-reliance.
While equipment is a necessary investment, Sealevel considers its dedicated workers to be its most important asset. There are currently 170 employees with an extensive range of skill and diversity. A handful of employees began in the early days of the company with the majority of workers from the South Louisiana area who are committed to the company's growth in this region.
Roth strives for an "open-door policy" with employees and encourages project managers and supervisors to do the same. Challenges are worked out by using a team approach and focusing on exhibiting integrity, innovation and safe performance. Everyone is important and safety has to be first.
"From a moral standpoint alone, safety really has to be number one," said operations manager Travis Schonacher.
An HSE director, HSE manager and onsite HSE representatives lead Sealevel's safety initiatives. Moreover, Sealevel has established a safety committee comprised of employees with different professional backgrounds. Together, the safety team oversees an extensive safety training program for new hires and existing employees. There is also specific training for project managers and supervisors and the development and implementation of specific site safety plans.
Schonacher is also the president of the PDCA Gulf Coast Chapter.
"One of the most important benefits of being involved in a PDCA chapter is the opportunity to interact and develop relationships with other pile driving contractors in a non-competitive atmosphere," he said. According to Schonacher, PDCA provides a wealth of information and opportunities to build relationships in order to foster success both within each company member and the industry as a whole.

Posted in PileDriver Magazine. Tagged as Edition 4, 2019.

The Hose Company

When navigating many industries with a very specific niche product, like North Carolina-based The Hose Company, doors open to new opportunities to assist customers. The Hose Company provides hose delivery service and on-site repairs 24/7, making many contractors productive even on the night shift.
"And, of course being huge race fans in Charlotte, N.C., we love helping out NASCAR teams," said Justin Robertson, certified mobile hose technician at The Hose Company.
At night service
"I remember the first 2 a.m. mobile repair call from a group in South Carolina, about 10 miles from us," said Rob Smith, The Hose Company's operations director. "These folks were building new warehouses and moving many concrete trucks to avoid traffic congestion during the daylight hours. They were also using multiple vibrating screeds for precise elevation control when suddenly production stopped dead. Think about it: it's 2 o'clock in the morning, full concrete trucks, sitting and spinning, and the precision leveling solution blows a hose."
The Hose Company Team received a quick call and were on the road moments later with supplies already stocked in their service fleet. It is incredible that a $13 part could have shut down a job until 7 a.m., but not anymore.
"Now, there is a choice." said Smith.
NASCAR support
The Hose Company received a Saturday call from Joey Logano Racing, a famous NASCAR team and driver.
"This team was building a kit car for one of the preliminary NASCAR races," said Smith. This team needed choices, without wasting time at a store as they were designing and moving fittings from custom to universal. They really needed The Hose Company inventory and experts on site to help make these adaptations. So, The Hose Company sent in a technician and his fleet vehicle, allowing the race team to walk right in and find all the parts."
Expanding since day one
The Hose Company began operations in 2013 as a supplier of hydraulic hose to the pile driving, drilling, marine construction, manufacturing and redistributing markets. This startup of six people has since grown substantially as the markets and clients have demanded industrial and sanitary hose offerings.
With growth like this, The Hose Company further expanded this year by opening a 7,000 square foot warehouse expansion and added additional loading docks to meet all the shipping demands of its hydraulic and industrial clients.
"We have added industrial and sanitary hoses to our product offering. So not only are we doing hydraulic, but [are] now offering new markets industrial hose and fittings," Smith said. "We cut our teeth on the toughest part of the construction industry, pile driving, while supporting all other construction sectors [and] added a focus on the waste management industry and material handling. Today, The Hose Company has mastered each area they have taken on and are supporting more sectors like the carwash industry, elevator companies and other OEMs that build equipment, like car crushers...."
The Hose Company started out selling B2B in the hydraulic markets. Today, they are doing much more with a fleet of retail and repair vehicles to handle on site with contractors, OEMs and more.
Educated responsiveness is a cornerstone of The Hose Company's strategy. The company's goal is to educate its customers on how best to care for and maintain hoses, but to also always be available when problematic situations occur. The Hose Company team believes their ability to help clients centers around a customer-focused inventory and superior educational resources.
"We want to speak the same language as our clients, so we offer one of the most comprehensive hose glossaries one can find online," said Luke Carpenter, hose team technician.
A manufacturer and distributor
The Hose Company manufactures Hydrauli-Flex, their brand of hydraulic hose in one-wire, two-wire, four-wire and six-wire hoses. The impressive part is The Hose Company carries and sells on a daily-basis 50-foot, 100-foot, 150-foot and 200-foot bundles of the large four-wire and six-wire hose. Many hose resellers in the market are working with The Hose Company as their supplier of this large hose.
The Hose Company is a major distributor for the products contractors know and trust from Anchor Fluid Power, Brennan Industries, Dixon Industrial, Kuriyama, Midland Metal, NovaFlex, NRP Jones, Thompkins Industries, Word Wide Fittings, ZSI and many others. The Hose Company's highly trained team can reference part numbers from all these major fitting sources to best assist clients in getting the right fitting the first time.
What's up in 2019?
In 2019, The Hose Company's big initiative was the expansion into the industrial parts hose, offering to start and service the entire job site. Customers that do pile driving will also need other hoses outside of hydraulics. They need lay flat hose, discharge hose, air flow hose and more.... When the company's repair fleet goes onto a job site, it can fix all hoses and fittings saving customers time and money.
"We really want to show our customers that we can deliver, and we deliver more more service, more advice, more help when they need it... just a lot more," said Smith.

Posted in PileDriver Magazine. Tagged as Edition 4, 2019.

 Binder Equipment Technology

New Jersey's most famous son once wrote that he was born to run, but you might say one of the Garden State's slightly less well-known sons was born to build.
Brendan Binder is the president and founder of Binder Equipment Technology, a Middlesex, N.J.-based company that supplies Leica Geosystems machine controls to a number of construction firms across the United States as well as a full range of support services.
Binder, along with his wife and company CEO Krissy, launched the independently-owned company in January of this year. He's hardly a newcomer to the heavy construction equipment industry, though. Prior to starting his own business, he was involved for many years in Binder Machinery Co., the company founded by his grandfather in South Plainsfield, N.J., in 1957 that was acquired by Komatsu Ltd. in 2016.
Binder says the lessons he learned working for the family-owned enterprise over the years continue to have a profound impact on the way he does business.
"Our focus was always on service and support for our customers and that's a philosophy we've carried forward into Binder Equipment Technology and something we take very seriously, which I think is a differentiator for us in the technology products distribution business," he said.
"I keenly understand the needs of contractors and the significant need of uptime and the cost of downtime that contractors can incur as it relates to construction equipment."
Binder knew soon after his family's business was sold that he wanted to start his own company. He also knew that he wanted to go in a slightly different direction, with a focus on machine automation and the growth opportunities that are available in the technology sector.
In March 2017 he attended CONEXPO-CON/AGG, North America's largest construction trade show, to explore potential partnerships for his new business. The very first exhibit he visited at CONEXPO was Leica Geosystems and signed a partnership agreement with the international manufacturer a short time later.
"I knew that Leica had a very strong reputation in machine automation and other precision products that they manufacture. I just knew that was a company that we wanted to partner with," he said.
Binder Equipment Technology offers a range of Leica Geosystems products for a variety of heavy construction projects, all with a focus on automation. That includes machine-controlled systems for bulldozers, excavators, graders and various other pieces of equipment.
One of the company's most popular offerings is the Leica iCON site construction software system that is geared specifically for the piling industry. As part of the system, a series of sensors are mounted on a machine's chassis and lead vertical system and are constantly determining where the lead is in relation to the machine body using a sophisticated GPS unit.
Shawn Dahl, Binder's technology solutions manager, says the Leica system is unique in that it allows the machine operator to do the work of several people.
"Instead of having to rely on a survey to manually lay out the fields, the operator is able to navigate the machine to the exact geodetic position of that designated pile location without having a surveyor in the field," he said.
"The machine is also able to [assess] where the pile is put in the ground and to gain information about how that pile was put into the ground. If it's a soil mixing situation, we're also able to extract data about the soil mixing [and] the depth that was achieved by that pile."
Binder Equipment Technology has already supplied the system to a number of larger civil contractors in the Eastern U.S. including New Jersey, Pennsylvania, Delaware, Maryland and New York State, including New York City and Long Island. The largest project the company has been involved with to date is 50 Hudson Yards in New York City. When complete in 2022, it will be the city's fourth largest commercial office tower at 985 feet tall with 2.9 million square feet of space.
Despite its involvement in several big-scale projects, Binder says his company plans to stick with the formula that made his grandfather's business so successful. A major component of that strategy is to continue providing education and training to clients and their employees on all products Binder sells.
"Education and training is key because when it comes to technology products, contractors who aren't already utilizing machine automation tend to shy away from it because of concerns about training and education for their employees," he said.
 "That's why we are very focused on ensuring that our customers' field support personnel are well educated and trained on the products that we sell and also have a direct line of support when they have questions they need answered."
One of the first decisions Binder made after launching his company was to join PDCA. It was in keeping with his family's philosophy of helping the organizations that help them.
"We've always felt it was important to have membership in industry organizations and associations, be involved in various committees and attend marketing functions because we understand the work associations do on our behalf," Binder said. "We also want to make that outreach to the pile driving market and really build our business by partnering with pile driving contractors throughout America who are looking to explore and implement machine automation into their organizations."
Although Binder Equipment Technology is not yet a huge player in the industry, the company's president says it is actively growing and plans to add more people in the near future.

Posted in PileDriver Magazine. Tagged as Edition 4, 2019.

 DuroTerra

In 2014, DuroTerra leaders took on a wonderful opportunity when they launched their company while working with Austria-based Tiroler Rohre, GmbH (TRM), a manufacturer of ductile iron piles. These piles have been used in Europe for more than three decades and in the United States for more than 10 years.
"The sister company of DuroTerra, LLC, is a specialty geotechnical contractor in the Northeast U.S. and has installed more than 50 successful ductile iron pile projects," said Rimas Veitas, P.E., who along with partners Chad Graybill and Christian Littlefield (owners of Helical Drilling and who have more than 80 years of combined experience in the specialty contracting and engineering industry) comprise the DuroTerra's corporate team.
Brendan Fitzpatrick, P.E., a prior vice president at Geopier Foundation Company, joined the team in 2014 as director of engineering/marketing and manages operations of the company.
With its corporate office and distribution yard located in the Greater Boston, Mass. area, DuroTerra is a distribution company specializing in ductile iron piles, which it distributes through a client base across U.S. and Canada along with select locations throughout Latin America.
"In addition to material supply, DuroTerra also provides its customers with project feasibility assessments and preliminary design evaluations based on geotechnical site conditions and foundation plans to help evaluate the construction and technical suitability of the system," said Veitas.
 "We also provide equipment and construction support to assist installers in getting adequately set up for a ductile iron pile job and following construction guidelines to aid in the installer's construction success."
Benefits of ductile iron piles
Ductile iron piles are a modular, low-vibration driven pile system. The system utilizes a medium-sized excavator and percussion (demolition-type) hammer to install the piles, making it well suited for constrained urban sites or interior renovation work where overhead clearances are 18 feet or higher.
"The equipment needed is simple and makes installation simple," said Graybill. "While the system has been used cost-effectively on wide-open sites, the vast majority of our customer's projects include building additions, interior retrofit work or tight, urban development sites. The system is versatile and can be installed to develop capacities ranging from 25 to more than 100 tons in either end-bearing on a competent bearing layer (i.e., rock or very dense ground) or by using an oversized pile shoe and continuously pumping grout during driving to create an efficient grout-to-ground bond zone for frictional capacity."
Littlefield added, "Projects primarily include industrial and manufacturing additions and improvements, warehouse retrofits, commercial and residential buildings and additions and the occasional bridge support and municipal application. When a project uses ductile iron piles, the pile can go 150 feet without mobilizing a large crane. All that is needed is an excavator."
When asked how contractors can find out whether ductile iron piles would be the right choice for their project, Littlefield said that besides meeting directly with project teams and participating in industry events, "Our team works with geotechnical contractors, engineers and owners to evaluate applicability of ductile iron piles for their projects. Involvement and feasibility assessment occur at all stages from early design phases prior to the selection of foundation systems through bidding (including value engineering opportunities) and even into construction when specified solutions are encountering issues and teams are looking for alternatives."
Littlefield says the system is more cost-effective compared to micropiles, which can help a contractor secure the job.
Fitzpatrick, who has more than 20 years of design/build geotechnical construction experience, concurs.
"I encourage all of our existing and future customers to provide us with project information (structural foundation plans, geotechnical reports, boring logs, etc.) to evaluate and discuss whether the system is well-suited for their project. While it'd be great for all projects to make sense for ductile iron piles, we recognize that there are many different foundation solutions available to project stakeholders. We want to make sure that our solutions are providing value against other options."
As for a project that stands out, DuroTerra was recently brought in as an alternative to a micropile system on an active project where a new interior mezzanine level was being constructed for an international shipping company. The project had overhead clearance restrictions of generally about 30 feet, but as low as 24 feet in some locations.
"After encountering conditions that required the specified micropiles to go deeper than planned, the project team was looking for alternatives to avoid costly foundation overruns," said Fitzpatrick.
"The ductile iron pile system was selected on a 1:1 replacement of the 50-ton micropiles and construction immediately proceeded to keep the project schedule on track. A total of 116 piles were installed in only six days, while working around existing distribution facility operations."
He adds that the success of the ductile iron pile system for this project has led to ductile iron pile solutions on three other similar projects for the same international shipping company.
"The most notable was a large interior project installed by PDCA member GeoStructures, Inc. near the Philadelphia International Airport. The project involved another mezzanine expansion and required more than 330 piles installed to depths ranging from 70 to over 100 feet to develop capacities of 45 to 75 tons. Overhead clearances were limited to around 35 feet in many locations, but did drop to 25 feet in limited locations. The pile installations were completed in four weeks while working around active facility operations."
[Editor's note: GeoStructures, Inc. received a PDCA Project of the Year Award for the above-mentioned project; read the full story on page 75 of this edition of PileDriver.]
These projects, Fitzpatrick says, along with a number of other similar jobs, illustrate some of the advantages of the system when working on projects with tight access, overhead clearance restrictions and vibration-sensitive conditions.
PDCA membership and the future
A relatively new member of PDCA, DuroTerra recently joined the association at the suggestion of Larry Moore, P.E, past president of PDCA and COO of GeoStructures, Inc.
"We joined as a way to become more connected with the pile driving community," said Veitas. "We are looking forward to being better connected with contractors in the driven piling industry."
As for the company's plans, Veitas says that like most companies, DuroTerra is focused on growth.
"From a start-up company five years ago to having successful projects with customers in about half of the U.S. and Canada we see growth opportunities both geographically as we develop a greater customer base in the U.S. and abroad, and also by raising awareness of the DuroTerra™ brand and the benefits offered by the ductile iron pile system. Despite its long-term use in Europe and availability in the U.S., many contractors and engineers are not yet familiar with the system and the substantial benefits it provides in the right application."

Posted in PileDriver Magazine. Tagged as Edition 4, 2019.

Sunroc Corporation

With approximately 850 employees across the U.S. in four regions northern Utah, southern Utah/Las Vegas, Idaho and Wyoming Sunroc Corporation provides construction materials and services throughout Utah and the Intermountain West for both public and private sector customers.
The company was first established in 1937 as Utah Service when founder W.W. Clyde purchased a small service station in Springville, Utah. Directly adjacent to the station, he added a hardware store and lumber yard. Since that time, Sunroc Corporation has continued to grow beyond the Utah Service hardware store and service station, expanding to nearly 50 operating locations including masonry block plants, aggregate facilities, construction offices, asphalt plants and concrete facilities.
"Essentially, Sunroc Corporation is a wholly-owned subsidiary of Clyde Companies, Inc., a family-owned and operated company headquartered in Orem, Utah," said Mark Wimmer, Sunroc vice president. "Our president, Scott Okelberry, oversees the growth, operations and vision of the company and reports to the president of the Clyde Business Group at Clyde Companies, Inc. His vice presidents, Russell Leslie and myself, lead the construction and construction materials divisions of the company, respectively."
Sunroc specializes in pile driving and earth shoring operations, including precast prestressed concrete piles, H-piles, pipe piles, sheet piles, soldier piles and soil nail/shotcrete, at present.
"We recently completed work on a high-profile project for UDOT, driving piles for the SR-68/I-215 Interchange Bridge," said Eric Hendriksen, general manager of the piling and shoring division.
This a major interchange that is relied on by motorists traveling between Salt Lake and Davis counties. Plans called for 16-inch by ½-inch wall pipe piles, driven [to] lengths up to 125 feet. We were chosen by the general contractor as a subcontractor for the pile driving work because of the relationship of trust and proven results we have with them.
Work began in July on UDOT's highest priority project, Mountain View Corridor 4100 S to SR-201, a two-year project consisting of four miles of new roadway with two lanes in each direction, with biking and walking trails, 13 bridges and six pedestrian bridges.
When asked how Sunroc differs from its competitors, Hendriksen doesn't hesitate.
"Our perfect safety record, for sure. Our core group of people has been together for decades and I believe we have far more experience than competitors in our area."
Added Wimmer, "Sunroc is unique in the large variety of construction and material services provided from earthwork, excavation, shoring, piling, ready mix, sand and gravel, asphalt paving and masonry products with an excellent footprint in the Intermountain West. What else differentiates us is that we are large enough to take on large projects, but still provide personal service and detail in each of our individual locations."
Leslie agreed: "Over the last few years through acquisition, we have significantly increased our footprint and have brought on some very qualified employees that are experts in their chosen fields. We strive to do the project right the first time. If there is an issue, we work to quickly remedy the situation. We have been very successful in doing multiple projects with the same customer. This happens because of our ability to establish and maintain exceptional relationships with owners and customers."
PDCA and the future
Sunroc has been a PDCA member for many years.
"My previous employer was a member from the early days of the organization, joining in the first or second year," said Hendriksen. "I have been connected for many years and have maintained membership with each change in business structure from Desert Deep Foundations LLC to DDF Inc. and now Sunroc. Aside from the benefits we derive (education, networking and making connections with other contractors, suppliers and manufacturers, etc.), I feel it's important to support the driven pile industry as a whole, helping promote, publicize and educate others on the benefits of driven piles, while alleviating unfounded concerns sometimes associated with driven deep foundations."
As for what the next five to 10 years hold for the company, Hendriksen said, "My plan is to continue for the next five or six years, training others to pick up the ball and keep moving it forward. I have learned a lot since my first experience with driven piles in 1983, and I still have lots more to learn. Hopefully, by the time I'm ready to step away, Sunroc will be widely recognized not only for excavation and civil work, but also as the most reliable and trustworthy source for driven piles and earth shoring in the region."
Said Wimmer, "The company plans to continue to grow and provide more services both organically and through acquisition over the next one to 10 years."
Leslie agrees, "There are still areas that I feel we have the ability to grow in geographically. As long as the markets continue moving forward in a positive way, we will continue to grow."

Posted in PileDriver Magazine. Tagged as Edition 4, 2019.

Deep Foundations for the Salt Lake City International Airport Redevelopment Program

During the summer of 2014, the Salt Lake City Department of Airports (SLCDA) broke ground on one of the most complex construction projects in Utah history. In order to keep pace with the demands of the nearly 23 million people that use its facilities each year, the SLCDA initiated a $3.6 billion redevelopment program that will transform the current Salt Lake International Airport into one of the nation's most efficient airports. The first phase of the program features a modernized three-story terminal building, two new concourses, several new parking structures and the longest bridge constructed in Utah all supported by a deep foundation system consisting of over 95 miles of driven steel piles!
Installing this massive deep foundation system by December 2018 was critical to keeping this high-profile program on schedule and setting the stage for its successful delivery. Ralph L. Wadsworth Construction Company, LLC (RLW) was the firm selected to shoulder the burden of getting the project started correctly. Working as a subcontractor to HDJV Construction, a joint venture between Holder Construction and Big-D Construction, RLW overcame a multitude of challenges related to schedule, design, safety and logistics.
Schedule
The schedule for pile driving operations was aggressive and unforgiving. From start to finish, the project required more than 5,300 separate pipe piles (16"×0.5"), and 550 H-piles (14"×102') to be delivered, driven, spliced, welded, cut and poured. (A partial aerial view of the site is in Figure 1.)
The schedule required the team to work year-round and in all types of weather conditions, driving 60 to 80 piles each day. At the peak of the work, RLW had more than 30 construction professionals working at the site, using day and night shifts as well as weekends.
Pile depths and weights
The individual pipe pile lengths ranged from 45 feet to 80 feet per piece (Figure 3), and the weight was 82.8 lb. per foot. Several piles were installed to depths that ranged between 88 to 120 feet, which required the team to splice piles together.
Logistics
This project required 26 different lengths of pile, many in excess of 80 feet. Beyond handling the sheer quantity of pile pieces, their length created challenges for transporting, storing and maneuvering them at the site. Manufactured in California and Mississippi by Skyline Steel, the piles were transported by barges and then by rail to Salt Lake City. Trucks with extra-long beds carried the more than 70-foot-long piles through city streets to the project site, transporting no more than six piles at a time. RLW carefully scheduled deliveries around traffic patterns and managed inventories to minimize the amount of storage space required on-site.
RLW's team also procured and modified specialized pieces of equipment to unload trucks and move piles around the site (as shown in Figure 4). These machines used clamping forks to hold the large piles in place while moving allowing the team to transport them efficiently and, more importantly, safely.
The massive size and scope of the entire construction program together with a single point of site access demanded extensive coordination with other contractors and trades working at the Airport. RLW met with other contractors several times each week to plan deliveries, adjust storage areas and coordinate sequencing details.
Special innovations: Techniques, equipment and materials
Several factors made this 130-acre site unique. First, the soil conditions and geology fluctuated substantially within the vast construction area. Second, the various structures each had specific engineering requirements that called for different pile sizes and lengths. Lastly, some of the work needed to be performed in small areas, either pinched between or immediately adjacent to existing structures still in operation. No two areas were exactly alike, which compelled a customized area-by-area approach to pile driving.
In order to efficiently drive pile in these varied conditions, RLW utilized its full breadth of equipment optimizing equipment strengths to specific challenges. Seven different sized ICE hammers, both hydraulic and diesel, were used according to area soil conditions and proximity to buildings. Six different sized Manitowoc cranes were used, engaging both swinging and fixed leads, to maximize production and safety.
For the work performed immediately next to the existing airport terminal, vibration and noise impacts needed to be minimized to avoid disrupting airport operations. RLW used special equipment and techniques to mitigate these pile driving affects, including predrilling, sound curtains, optimized hammer selection and automated vibration monitoring with real-time text and email notifications if vibrations reached allowable limits.
Many piles were specified to be driven to depths of 120 ft., which required splicing that had to be UT tested. In order to maintain the aggressive schedule and execute high quality splicing operations, the team drove the first (bottom) pile during the day. Night shift crews welded the second (top) pile together with the first (as shown in Figure 2). Day shift crews finished driving the extended pile the following day. By performing all the welding operations at night, RLW was able to keep the hammer continuously working through daylight hours to maintain the schedule. This efficient approach allowed the team to continue installing 60 to 80 piles each day.
Unique application of piles
Part of this project included extending an existing concrete tunnel proposed to provide underground transportation for passengers between terminals. The tunnel had a bottom elevation of 28 feet below grade, and since the water table was only five feet below grade, an earth shoring and dewatering system was required to expose the work area.
A significant challenge arose when the geotechnical engineer-of-record calculated that the required dewatering efforts would cause the tunnel to settle about seven inches the structure's allowable settlement tolerance was less than half an inch.
The owner and the design team developed several designs to support the existing tunnel and limit the settlement due to dewatering. The frontrunner was a proposed solution to use micropiles drilled through the tunnel's six-foot-thick mat footing floor. The significant drawback to this solution was that it would damage the tunnel's existing waterproofing and expose the tunnel to potential long-term water-penetration issues.
Although this work was outside RLW's original scope, its on-site management team learned of the problem and seized the opportunity to find a better way using driven piles. RLW's team proposed driving 20 piles to a depth of 120 feet on both sides of the existing tunnel. Beams would then be placed on top of the driven piles and would span overtop the tunnel. These beams would then be connected to the tunnel's lid using threaded rods and welded connections. Hydraulic jacks installed between the beam and driven pile would allow the system to adjust to compensate for any differential settlement that might develop along the length of the tunnel. The strength of RLW's driven pile method was that it was quick, simple, flexible and required no modifications to the existing footing below the water table mark.
After reviewing RLW's solution, the owner and design team scrapped the other designs and selected the driven pile option, concluding that "it offered the best value to the project" (Figure 7 depicts this solution). The implemented solution worked beautifully.
Construction problems and creative solutions
Part of the redevelopment program included a pedestrian bridge to connect the new terminal to the existing airport facilities. The original plans for this bridge used 36-inch and 48-inch caissons drilled to depths approaching 80 feet. Once installed, the plans called for a 10-foot to 13-foot concrete column to then be poured as a separate component on top of the drilled shaft.
Challenges for the general contractor arose in the constructability of such a design in the middle of an operating airport. Situated between the airport's busiest domestic terminal and the international terminal, the structure spanned over a central walkway, the staff bus stop, the long-term parking bus stop and the airport's retail delivery access point. In order to minimize disruptions to daily operations and reduce safety risks to passengers at the airport, this work had to be completed at night, with working hours restricted to an eight-hour window between 9 p.m to 5 a.m. Moreover, the actual production hours were further limited by the requirement to mobilize all equipment to the work area, perform the work, clean, demobilize the equipment to a storage area and reinstall safety devices all within the eight-hour window.
Once again, RLW saw an opportunity to improve this design concept using driven piles. Its team met with the general contractor, airport, geotechnical engineer, and structural engineer and proposed revising the design to use continuous 36"×0.5" and 48"×0.5" driven steel piles instead of caissons and columns. This structurally acceptable design allowed the foundation work and column work for the bridge to be completed as one unit, cutting the construction time by half. The new piles were driven and vibrated to depth, and were left extending 10 to 12 feet above the existing ground elevation. Beyond its schedule advantage, this approach also had other benefits to the project. First, it did not require holes to remain open for any length of time, thereby eliminating the public safety risk of the proposed design. Second, it afforded the use of dynamic testing methods, which immediately verified the pile capacities and allowed the embedment length to be reduced by 33 percent saving the project significant cost savings. RLW installed two piles per night with minimal disruption to airport customers and operations. (Construction of the pedestrian bridge is shown in Figure 8.)
Innovative project management
Typically, a new airport would be built at a separate location either across town, similar to Denver's approach with its international airport, or on a parcel adjacent to an existing airport. The new Salt Lake City International Airport is unusual because it is designed to be constructed in phases on the existing footprint. This presented numerous challenges that required a high level of coordination between the construction team and airport operations.
RLW's pre-construction support for the foundation design of the pedestrian bridge and the dewatering and earth shoring of the tunnel demonstrates a spirit of true partnership. Participating in the design process was not part of the firm's scope or contract, yet RLW's project team repeatedly demonstrated a willingness to share ideas openly and a passion for thinking creatively. This collaborative approach was consistent with the Construction Manager at Risk (CMAR) contracting method used by the airport and the general contractor, which allowed the construction team to provide input during design.
During construction, RLW's management team adopted a proactive management approach for scheduling, pricing and coordination. They coordinated with the owner's construction and QA/QC teams on quality requirements, hold points and materials testing and certification. They coordinated with the FAA to ensure that all piling and foundation operations met federal guidelines including those for crane heights and temporary lighting for night construction work. Using weekly schedule updates, the team pre-planned all operations, using night shifts and weekends to complete key activities on time.
This proactive pre-planning approach paid off during the summer months when temperatures rose to over 100 degrees during a critical time when significant field welding was required. The heat posed a major safety risk to the workers dressed in full leathers. Even cooling vests and shaded work areas were insufficient to protect the welders from heat exhaustion. Night work was discouraged at the site due to its potential for negative impact on flight operations. Exceptions required a detailed plan and routinely took over two months to approve. Fortunately, RLW's management team identified the risk of approval delays as part of an internal brainstorming session held well before the start of work. As a contingency, the team had submitted several alternate work plans to the airport for review, and worked through the approval process for each, not knowing if they would ever be needed. One of these included a directional lighting plan that allowed limited work at night. Armed with an approved work plan, RLW had the flexibility to separate the crews, leaving some to drive pile in the day and moving others to weld at night. Not only did this mitigate the safety risks from the heat, but the cooler temperatures also expedited UT weld testing and ultimately allowed the project to gain 17 days on the schedule.
Conclusion
In summary, RLW met the challenge of this difficult job through the use of cost saving value engineering methods in the design and construction of the deep foundation systems. Both client and owner appreciated RLW's quality of work and their ability to meet a demanding project schedule in a safe and productive manner.
When overall excellence is discussed concerning large deep foundation projects, partnering with the owner and stakeholders must be at the forefront. RLW's relationship with its owners and general contractors is second to none due in large part to the open communication and close collaboration maintained throughout the project. The project NCR log never carried more than five items at any one time and project completion showed less than 25 total issues logged. The success of this project is a testament to the close collaboration within the project team is an excellent example of how the simplicity, durability and flexibility of driven steel piles still reigns supreme in the deep foundation marketplace.

Posted in PileDriver Magazine. Tagged as Edition 4, 2019.

Valero Refining C5 Alkylation Project

In August 2017, Cajun Industries was approached by Burns & McDonnell to assist in a constructability study, as well as a budgetary pricing exercise for the new C5 Alkylation Unit at the Valero St. Charles facility in Norco, La. It did not take long to realize that the project would present a challenge for the Cajun team. The new Alky unit would be located inside the existing facility on a footprint that was barely larger than one acre in size. Nearly 800 14-inch by 90-foot-long precast concrete piles were scheduled to be installed in a space that measured roughly 200 feet long by 200 feet wide.
Early works
At this point of the project's life, the engineering was in the early phases. The project team, composed of Burns & McDonnell and Valero employees, knew the unique and challenging project would present many obstacles along the way. Approximately eight months before the project began, Burns & McDonnell reached out to Cajun and began discussing the many possible strategies for execution.
The design for the new Alky Unit involved large foundations ranging from five to nine feet below the existing grade. Cajun's Deep Foundations Unit along with Cajun's Baton Rouge Civil Business Unit worked together to present two different options for the project. The plan was simple either drive piles first or dig first. Given the poor soil conditions in south Louisiana, the decision was made to install piles from existing grade using a pile follower to reach design top of pile elevation. In addition to this execution strategy, Cajun used its sheet pile design abilities to engineer and install sheet piling around three of the four sides of the project footprint. The sheet pile retaining system would allow the foundations to be excavated safely without undermining the adjacent roads.
Challenges and solutions
As Cajun prepared to mobilize the project, the team began putting together a plan to work safely and efficiently while operating in such a small area. Surrounded by roads on three sides and an operating unit on the other, the only laydown room Cajun had available was the project footprint itself. It was recognized very quickly that storing full length 90-foot precast concrete piles would not allow for much maneuverability. Additionally, Valero's safety policy states that contractors must pre-drill any pile locations that are within the length of the pile to prevent damage to adjacent structures.
At this point, it was very clear that two-piece, spliced concrete piles would be necessary to execute efficiently. By utilizing spliced piles, the project team was able to reduce crane size as well as cut the required laydown area in half. Cajun solicited Boykin Brothers for the fabrication of the precast piles on the project. Together, they were able to utilize two different splices. Since not all piles carried a load in tension, a common drive fit compression splice was used on approximately 20 percent of the piles, saving the project time and money. The remainder of the piles carried a tensile design load. These piles would be cast using the Liemet Tension splice. The Liemet splice provides a cost effective solution without spending excessive time and energy to get the job done. Four pins, one at each corner, delivers a reliable connection that is strong enough to bear almost any tensile load.
Scope of work
The Valero Refining C5 Alkylation Project provided an opportunity for Cajun to showcase multiple facets of its pile installation abilities. After successfully installing six probe piles and performing dynamic testing on each, a static test pile location was determined. After installing the four reaction piles and erecting the test frame, Cajun switched gears to sheet piling while the 14-day load test setup time ensued.
Cajun was tasked with providing a stamped design engineering package to install sheet piling on three of the four sides of the project. Knowing the foundation placement would require deep excavations along with the heavy road traffic that took place just on the other side, Cajun implemented the temporary retaining system approach. After the design was approved by Burns & McDonnell engineering, the project team began procuring and installing over 150 pairs of sheet piling. Cajun worked together with Skyline Steel to develop a plan consisting of multiple custom corners and almost 700 wall feet of NZ-19 hot rolled sheets.
Just as Cajun was completing the sheet piling installation, the test pile program was complete and it was time to enter into production. Cajun began installing production piles in mid-July 2018 with a target completion date of Oct. 31 Cajun successfully installed the 797th precast concrete pile exactly on Oct. 31. The execution by the project team was nearly exactly as planned. Battling the south Louisiana summer rainstorms coupled with extreme temperatures, Cajun performed day in and day out completing the project on time and with zero injuries.
Safety
Cajun's number one priority is the safety of its employees. The company's goal is to foster an atmosphere where employees are confident in their safe return home each day. Cajun instills a safety culture that allows everyone to feel comfortable stepping up to recognize and correct any unsafe conditions or hazards that may arise. This was consistently displayed by field employees exercising their stop work authority to prevent hazards before they became an incident. On a more detailed level, Cajun uses a mentoring program where any employee that has been with the company for less than 90 days is assigned an experienced mentor who is responsible for coaching and instilling the Cajun safety culture in new personnel. The mentorship program allows all Cajun employees to grow and succeed in their new position.
In addition to the deep-rooted Cajun culture, the project teams implement a well-funded incentive program for its craft level employees. Each employee received a gift for a job well done at the end of the project. These gifts included monthly project safety lunches, along with the end-of-project gifts like power tools, fishing gear, iPads, outdoor cookers and big screen TVs!
Completion
In the end, Cajun was commended by Burns & McDonnell and Valero for completing a successful and safe project. The Valero C5 Alky project was a true testament to Cajun's continued excellence in construction.

Posted in PileDriver Magazine. Tagged as Edition 4, 2019.

Foundation Support for International Shipping Company

The foundation support for this international shipping company's project had to be constructed inside the active warehouse under an expedited schedule without disruption to concurrent facility operations. The client required areas of the building be turned over on a nightly basis for use by their operations. This meant that cleanup of pressure grout and spoils generation, along with minimal vibration, were of paramount concern. GeoStructures and fellow PDCA member, DuroTerra, worked with the project geotechnical engineer, Dynamic Earth, to develop a unique application of small-diameter DuroTerra ductile iron piles (DIPs), driven inside with low headroom equipment, to successfully achieve 90 to 150-ton ultimate capacity in soil without a pressure grouted bond between the pile grout-soil interface. Over 300 piles approximately 75 feet long were successfully installed with multiple rigs in less than a month to meet the client's turnover dates a feat that would not have easily been accomplished using drilled micropiles or other deep foundation techniques.
Innovative methods
Small diameter DIPs were driven in five-meter sections with a unique plug-and-drive connection that develops a cold (friction) weld when driven using a high frequency breaker hammer mounted on an excavator, which rapidly advances the pile through soil with minimal vibration. The compression fit bell and spigot connection enables DIP sections to be driven to depths of more than 100 feet and achieve moderate to high capacity in end bearing. Although only used as reaction anchors on this project, the system can also be installed with an oversized end cap to create a grouted friction pile by pumping grout during installation.
Unique application of piles
DuroTerra DIPs, typically driven to end bearing on rock, achieved their capacity terminating in dense granular and stiff clays as project geotechnical borings did not encounter rock.
Construction problems and creative solutions
The challenges
Adding deep foundation support within an existing active warehouse facility presented several challenges to the team:
Finding a cost-effective foundation solution which could be installed in an efficient, time-sensitive manner.
Constructing foundations inside the active building without disruption to operations or generating spoils and with minimal vibration.
Develop 90- to 150-ton ultimate pile capacity in soil where the bearing stratum generally began 65 feet or deeper below ground surface and rock was not reachable.
Install piles inside the warehouse with low headroom equipment and minimal horizontal clearance working around existing structure and active distribution equipment.
Soil conditions consisted of five to 10 feet of sandy fill with variable amounts of clay and organics, overlying 50 to 55 feet of very loose to loose alluvial sands, underlain by 20 to 25 feet of denser alluvial sands, overlying stiff to hard residual clays. Grouted micro-pile and ground improvement options were not compatible with the operational restrictions or soil conditions, so the geotechnical engineer recommended a DIP foundation be used to support the new column footings.
The solutions
GeoStructures and new PDCA member, DuroTerra, worked with the project geotechnical engineer, Dynamic Earth, to recommend supporting the new mezzanine footings on a DIP foundation system. DIPs had numerous advantages over a drilled micropile or traditional driven pipe or H-pile:
Uses a high frequency impact hammer for installation, which reduces vibrations to very low levels.
DIP elements come in 16.4-foot (5 m) long sections with a bell and spigot connection, which eliminated the need for threaded or welded splices, minimized waste and provided a workable length pile for the limited site head room, all things that sped up construction.
Installed with a small excavator, allowing for construction with as little as 22 feet of headroom working within a small footprint at each pile cap location.
Driven to end bearing, the DIPs did not require a pressure grouting operation to develop capacity between the grout-soil interface.
Using a design-build approach and multiple load tests performed as production progressed, the designers were able to optimize pile design lengths, capacities and reduce the number of piles to support the footings in the dense lower alluvium and the hard-residual clays.
Project management
Production DIPs were installed to the top of the bearing stratum about 65 feet below ground surface while four static axial load tests were performed concurrently to maintain the aggressive schedule. Once load tests confirmed DIP design capacity, piles were driven to final tip elevation.
Design changes to driven piles
The project team ultimately selected DIPs over drilled micropile or traditional pile or steel piles due to cost, schedule, operational and performance advantages. This was the right solution for the client.

Posted in PileDriver Magazine. Tagged as Edition 4, 2019.

Hudson River Seawall/Green Island Condo

CD Perry of Troy, N.Y., a is a heavy civil, marine and industrial contractor. The company was awarded a contract by Luizzi Brothers of Albany, N.Y., a private developer and site work contractor, to install 525 timber pile in support of the foundation for a seawall built on the face of the island on the shore of the mighty Hudson River. The overall project is a $65-million transformation of an abandoned oil terminal in Green Island, N.Y. to a luxury condominium site including a marina, restaurant and performing arts amphitheater, the latter of which CD Perry was contracted to install the permanent sheeting.
The timber piles were installed during the harsh winter conditions in upstate New York using a few classic pieces of machinery: a 1972 Vulcan 1 single acting air hammer powered by a 1979 newly rebuilt Ingersoll/Rand 750 CFM air compressor and combined with a newer 2015 Tadano Mantis 15010 telecrawler.
To increase efficiency for driving the piles, the holes were predrilled with a Kobelco SK70 mini excavator equipped with a rotary attachment, which kept ahead of the pile crew.
The timber pile phase of the project was completed on time and on budget with the coveted combination of safety and production.
The project team included a combination of CD Perry personnel: operations manager Lance Farrell; project manager Dan Espey; assistant project manager Jared Henkel; and crew members Todd Beauharnois, Toby Adair Don Emory and Nicolle Benjamin. Coordination between Luizzi Bros. project team members Chuck Pafundi (project manager) and Brian Gross (superintendent) and Alex Ryberg with GRL Engineers, the testing company, was critical to the project's success.
"The project faced some upfront challenges with the winter conditions, as well as the compressed overall schedule being one of the first activities on the critical path of a $65-million project holds a lot of responsibility," said Tyler Fane, general manager at CD Perry. "I'm very proud of our team in their accomplishment of providing satisfaction to yet another project owner, and getting the job done safely and efficiently."

Posted in PileDriver Magazine. Tagged as Edition 4, 2019.

Permanent Canal Closures and Pumps, Cofferdams and Permanent OPEN CELL™ Retaining Walls

The Permanent Canal Closures and Pumps (PCCP) project is the capstone piece of New Orleans' extensive hurricane risk-reduction system constructed following Hurricane Katrina in 2005. The project encompasses three separate pump stations and floodgate structures located at the mouths of three outfall canals on the south shore of Lake Pontchartrain. These three canals, running from the south to north, act as the primary conduits for discharging stormwater from New Orleans.
Prior to Hurricane Katrina, these canals were operated with pump stations located in a series two to three miles upstream of the mouths at Lake Pontchartrain. This left long stretches of levee on each side of the canals exposed to storm surges entering from the lake. Three levee failures occurred along these canals during Katrina two at London Canal and one at 17th Street Canal. The failures resulted in major flooding of the city, causing catastrophic damage and loss of life.
Following initial canal levee repairs after Hurricane Katrina, the US Army Corps of Engineers (USACE), in partnership with the Louisiana Coastal Protection and Restoration Authority (CPRA), took action to move the line of flood protection to the mouths of these three canals at the edge of the lake. By cutting off the storm surges from Lake Pontchartrain at the entrance to the canal, more than 10 miles of canal levee would no longer be exposed to storm-surge water elevations, significantly decreasing the risk of failure.
Initially, temporary pump station and gate systems were installed (the interim closure structures) at each canal to provide this increased protection. The goal of the PCCP project was to replace these temporary structures with permanent pump stations designed to protect against a 100-year storm surge and evacuate the stormwater from the associated design event. This closure system would also allow non-storm canal flows to bypass the pump station and flow directly to Lake Pontchartrain. During specified storm conditions, this bypass canal is closed off by lift gates to complete the floodwall protection at the mouth of each canal. Stormwater in the canals, collected from the New Orleans area, is then pumped over this flood barrier and into the lake.
The project was completed by the design-builder PCCP Constructors JV (Kiewit Louisiana South Co., Traylor Bros. Inc. and the M.R. Pittman Group, LLC) with Stantec, Inc. as the lead designer, PND Engineers, Inc. as the cofferdam designer, and GeoEngineers, Inc. as the cofferdam numerical modeler.
The PCCP project incorporated some of the deepest and largest excavations ever accomplished in this region and required a significant structure, along with careful construction sequencing, in order to successfully complete the project. Two cofferdams and two substantial permanent retaining walls were required for each site. For the small cofferdam enclosing the by-pass structures, a classical, braced-frame cofferdam was deployed with an excavated depth of 18 feet. The second, larger cofferdam enclosed the pump station footprint. The largest of these pump station cofferdams at the 17th Street Canal was 265 feet long and 165 feet wide. The deeper pump station cofferdams posed compelling challenges, given the 50-foot excavation depth and the necessity to limit interferences and penetrations from the cofferdam and the permanent structure.
The New Orleans area presents extreme challenges to a deep cofferdam. Common to most of the southern Louisiana region is a high water table. Underlying soil deposits are primarily composed of unconsolidated clays with occasional sand layers to a substantial depth below the surface. The history backdrop of the PCCP project included the notorious geotechnical failures near the site; the difficult, soft ground conditions; large magnitude of hydrostatic loading; the uniqueness of the cofferdam support system; and the need for unobstructed access to the subsurface permanent work.
After evaluating preliminary designs and overall costs of different cofferdam systems, the design-builder selected the OPEN CELL SHEET PILE™ system. An OPEN CELL system with a pile-supported tremie is an innovative and unique design application for a deep cofferdam.
The design was made complex by the project criteria, soft ground conditions and complex site layout. In addition, the pump station cofferdams needed to be fully un-watered to EL -50 feet without excessive ground improvement. The project footprint at each site was limited for by-pass structure and pump station due to the existing canals, levees and floodwalls where the design-builder needed to maintain canal flow throughout construction. This meant that each step of design required careful analysis and operations planning to protect the site and the city from storm and flooding events. This required detailed planning in the site layouts, operations and sequence of construction.
Innovative measures
The OPEN CELL cofferdam design was a unique application of the OPEN CELL SHEET PILE system. Rather than using the system to support an engineering fill structure, the system supported the in-situ soft soils of the site and retained and sealed the cofferdam on all four sides from water intrusion into the large field of construction. The design-build team advanced the OPEN CELL system design under an intense review process by the USACE, given that no guidelines existed for such a structure within the USACE's design practice. The team presented and defended this shoring method, which had never before been used for a project of this magnitude and historical legacy.
Meticulous force-based design, soil structure interaction numerical modeling and physical testing were all techniques used to present and gain USACE acceptance of the shoring design. The cofferdam in which the impressive permanent pump stations would be constructed was a short-lived but vital feature to enable the design-build team to bid, win and successfully deliver a major infrastructure project to USACE for the civil defense of New Orleans from storms and flooding.
For the pump station designer, the OPEN CELL cofferdam offered flexibility in design development of the permanent structure without any need to contemplate or coordinate the locations of obstructions or interferences from temporary cofferdam struts or braces.
For the construction team, the resulting cofferdam system enabled planning of work operations completely free of obstruction or interference, with optimal production rates and the ability to place large equipment near the face of the cofferdam and hoist large equipment and materials into the field of construction.
Unique application of piles
Unlike a braced cofferdam and closed cell structure, the OPEN CELL structure mobilizes the available soil resistance via the large exposed diaphragm area of the tailwall system. The tailwall is simply a long series of flat web sheet pile that extend into the retained earth at junctions between each curved face arc. Adhesion and friction of soil to the flat web sheet pile creates a portion of the net resistance. The extensive series of interlocks in each tailwall, acting similar to the deformation on rebar, mobilizes the balance via bearing against the soil fabric. The two mechanisms and the selected spacing of tailwall elements create a block of mechanical stabilized soil, with the face arc retaining the forces arising from earth and hydrostatic pressure, as well as from equipment. This configuration is also highly efficient, given that steel sections are almost exclusively working in tension. A simple analogy is that the face arc of the OPEN CELL system is like the canopy of a parachute, and the tailwall mimics the effect of shroud lines anchoring the face arc to the surrounding soil. In soft ground, the mechanism is most effective, since even with weak soil the available capacity can be mobilized across a large area.
Given the extreme hydrostatic pressure in the unwatered condition, the OPEN CELL cofferdam design for PCCP captured and utilized the driven pipe piles to provide stability at the base of the excavation and to augment the lateral capacity of the tailwall system. While OPEN CELL walls were able to safely support the excavation work prior to unwatering the cofferdam, the extreme earth, equipment and hydrostatic loading on the cofferdam system after unwatering required additional support. For this support, the design-build team incorporated the lateral and vertical support of a tremie-placed concrete seal slab and permanent piles in the bottom of the cofferdam to support the base of the OPEN CELL cofferdam walls. This component was common to all three project sites.
The cofferdam and tremie slab acted as an integrated system to enable the design-builder to perform the deep excavation required to build the pump station foundation and superstructure in a dry work environment. The tremie slab was sealed, which meant the slab resisted full hydrostatic 1.6 tons per square foot of uplift and soil heave pressure under the slab without venting or water pressure relief pumping from under the slab. The challenge of the sealed slab was to develop a system strong enough to safely support the uplift pressure, yet efficient in order to limit the depth of excavation to place the seal slab. A conventional gravity-supported seal slab would have needed to be over 30 feet deep to resist the 51 feet of water head pressure at the base of the slab. This slab depth would have resulted in additional excavation and cofferdam wall undermining.
In order to optimize the concrete seal slab, the design-build team incorporated the tension capacity of the permanent pipe piles designed to support the permanent pump station structure. By "nailing" the temporary concrete seal slab to the underlying soils, the slab achieved additional uplift resistance against the large hydrostatic forces. At the 17th Street pump station cofferdam, 465 separate 24-inch- and 30-inch-diameter pipe piles and adhesion to perimeter cofferdam sheet piles helped to provide uplift resistance hold down the concrete seal slab.
A single shear ring welded to head pipe pile provided reliable mobilization of the concrete seal tributary to the pile section. Concrete adhesion to the temporary cofferdam sheet piles provide vertical resistance to uplift around the perimeter of the cofferdam. The design-builder was able to achieve high production rates and tight tolerances while driving the permanent piles through highly turbid waters within the cofferdam prior to unwatering. The final top elevation of the permanent piles were 50 feet below the water surface. This underwater pile driving was made possible by the use of hydraulic impact hammers.
Cost saving measures
The OPEN CELL cofferdam represented a material savings on steel versus a traditional braced frame cofferdam alternative. However, the primary cost saving associated with the cofferdams was the efficiency of construction after the sheet piles were installed. The OPEN CELL cofferdams provided a free field of construction within the cofferdam excavation across a large area. Cost-saving efficiencies were realized in the excavation of the cofferdam and the construction of the permanent structures within the cofferdam confines. This free field of construction allowed for the placement of large permanent equipment, formwork panels and material quickly and safely without having to adjust or allow for internal bracing and the sequential removal or re-strutting of cofferdam walls and walers.
The robust strength capacity of the OPEN CELL cofferdam system also permitted the construction crews to place heavy equipment loads near the cofferdam face without additional pile supports to distribute the load away from the walls. This free field of operation outside of the cofferdam also resulted in efficiencies and cost savings in construction.
Innovative project management
The PCCP project was developed as a design-build project the first major project of its kind for the USACE, MVN District. Under this context, the design of the pump station, pump station cofferdam and permanent retaining walls were developed concurrently in order to compress schedule and deliver the project on time. In order to execute the project successfully, the cofferdam design and subsequent start of construction needed to occur before completion of the permanent pump station design. Simultaneously, both the pump station and pump station cofferdam designs were subject to independent design review by USACE and their engineering and agency partners.
The cofferdam design was developed based on the initial design development and general project criteria of the pump station and surrounding support structures. Modifications to the cofferdam occurred in real-time as design progressed on the permanent pump station and surrounding structures. The open field of the OPEN CELL cofferdam allowed for additional flexibility and optimization for the permanent structure design because internal bracing or re-strutting of the cofferdam walls was not required.
Management or mitigation of environmental considerations
The OPEN CELL cofferdam system proved to be an optimal and robust solution to achieve the stated USACE design objectives for the PCCP project. These objectives were consistent with the project mission to provide for public safety and property protection within New Orleans.
The city and surrounding areas are now better protected as a result of the project. The threat of adverse environmental ramifications from wide-spread flooding of the surrounding neighborhoods and city are immense as evidenced by the results of Hurricane Katrina. The application of this innovative support of excavation method using driven pile technology will continue to grow and evolve to address new environmental issues that arise from society's demands and new pressures arise from the effects of climate change.

Posted in PileDriver Magazine. Tagged as Edition 4, 2019.