St. Lawrence Cement Company engaged the services of Dente Engineering to conduct a Preliminary Geotechnical Investigation of sites in Camden, New Jersey and Philadelphia, Pennsylvania. The sites were being considered for development with a new Slag Cement Grinding Building and Bag House, 100,000 Metric Ton Bulk Storage Piles and 50,000 Metric Ton Silos up to 225 feet in height. The project also included the rehabilitation of an existing relieving platform dock and the construction of a new dolphin system and ship loader with connecting conveyors along the Delaware River. The Camden site was eventually selected and a detailed Geotechnical Study of the site was undertaken.
The surficial overburden at the Camden, New Jersey site consisted of fills overlying a very loose inter-layered deposit of silt, fine sand and peat extending to depths of about 25 ft. below grade where glacial outwash was encountered. The outwash extended to bedrock at depths estimated at several hundred feet. Older buildings in the area, one to four stories in height, and the existing relieving platform docks were supported upon timber friction piles.
The development planned at the site posed several design challenges in the selection of suitable foundations for the varied structures because of the large axial and lateral foundation loads, vibratory loadings and the settlement limitations of the mill and associated conveyors and storage silos. To assist in the selection of the most economical foundation type, a test pile program was undertaken and included both dynamic and static axial load testing of nominal 11 to 16-inch diameter open and closed end steel pipe piles and timber piles. A lateral load test was also conducted on a 16-inch steel pipe pile as part of the program.
Based on the results of the pile test program, the Mill itself was constructed upon a six-foot thick concrete raft foundation supported upon 50 plumb and battered 16-inch concrete-filled closed end steel pipe piles. Similarly, the silos were constructed upon an eight-foot thick concrete raft foundation supported upon about 500, 16-inch concrete-filled closed end steel pipe piles. The relieving platform was stabilized with H-Piles and the mooring dolphins and ship loader were supported upon 120, 18 to 60-inch diameter steel pipe piles. The more lightly loaded Office Building, Baghouse and Conveyors were supported upon wood piles. Pavements at the site consist of cast in place concrete. Roller compacted concrete was used to form the heavy equipment pavement beneath the bulk material piles and in heavy traffic areas of the site.
Dente Engineering provided geotechnical engineering services in connection with this development. These services included conducting a site reconnaissance; monitoring of test borings, observation of the pile test program, performing analyses and providing recommendations relative to foundation design and construction, including installation criteria for driven piles, review of construction documents, construction observation, and designing a settlement monitoring program and evaluation of its results. |
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