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.

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.

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."