Tough Driving Conditions At Grand Calumet River Remediation
Sometimes projects turn out to be easier than expected, but La Crosse, Wisconsin-based J.F. Brennan Company, Inc. knows you can't count on that. That's why the experienced piling and dredging specialist tries to anticipate the unanticipated. Such was the case at the Grand Calumet River remediation project in Gary, Indiana, where J. F. Brennan was hired to dredge nearly six miles of the river.
J.F. Brennan was the dredging subcontractor to Earth Tech, who was employed by U.S. Steel - a company that had been working with the EPA on the Grand Calumet River project since the early 90's. J.F. Brennan's portion of the project involved removal of impacted sediment, thereby widening and deepening the channel in a portion of the river that had been closed by silt.
"This was a very complex project," commented Anthony Binsfeld, president of J.F. Brennan. "It is the largest environmental remediation project ever done with hydraulic dredging in the western hemisphere."
The Grand Calumet River project had three phases. First was the construction of a CAMU (Contained Active Management Unit), a structure into which the dredged spoils are placed. The second phase entailed construction of a project-specific water treatment plant - a system designed to clarify return water before discharging it into the river. The final phase was the hydraulic dredging. That involved the removal of more than 700,000 cubic yards of impacted sediment and placing it into the CAMU, a permanent holding area that will be capped once the material has been dewatered.
During the course of project planning, the project team engaged in some "what if" contingency planning. That led to a review of bank stability because of the proximity of a U.S. Steel coke plant that had been located on the river for over 100 years. "From the review we concluded that, after dredging, there was a bank failure likelihood," Binsfeld recalled. To prevent the bank from caving in and disrupting plant operations, the riverbank had to be stabilized before dredging could begin. Consulting engineers conducted a slope stability investigation and recommended installation of steel sheet piling.
Due to the hard driving soil conditions, J. F. Brennan found it difficult to install piles to the required depth. "From borings that gave us blow counts in excess of 100-blows/ft., we knew the job was going to be difficult," Binsfeld remarked. "We had a list of methods to use and tried several drivers."
Initially, J.F. Brennan tried a mid-sized vibratory driver with mixed success. Some sheets could be driven to grade, but not at the desired production rate. Next they tried impact hammers, but found they were causing excessive damage to the pile tops. Finally, Binsfeld turned to Hammer & Steel for help. "I've worked with Joe Dittmeier for many years," he explained. "Hammer & Steel helped us find the best equipment for the job."
The advantage that a company like Hammer & Steel offers in a situation like this is that they have such a large range of equipment available. "Some of our competitors represent only one manufacturer," explained Hammer & Steel's regional manager, Mike Ormsby. "We've gone out and sought the best products within a number of different categories from a number of different manufacturers," he said. With such diverse product offerings, Hammer & Steel has a unique ability to solve a wide range of problems.
"When J. F. Brennan came to us, they had already tried several methods," Ormsby recalled. Since they needed to pick up production, Hammer & Steel suggested trying two PVE Model 52M vibratory drivers-equipment much larger than normally required for the 40' piling sections. They worked very well.
"These PVE systems are an extremely high quality tool, able to drive piling in the toughest driving conditions," commented Ormsby. The 52M-system features 4500 in. lb. eccentric moment, a 750 HP power unit, and forced lubrication of the exciter gearbox.
The pile driving work began in November 2002 and was completed in March 2003. The units performed trouble-free. The unique warm-up features came in handy during the cold months of January and February 2003. Approximately 3,000 wall feet of JZ-120 heavy cold-formed piling was installed.
"Even with the PVE units, it was still tough driving," said Binsfeld, "but they worked well. It was a challenging project, as we knew it would be. We relied on Hammer & Steel to help out, and they came through for us."