Performance of an Anchored Sheet-Pile Wall

Port of Freeport has built a new General Cargo Dock and Transit Shed. The project included a 12m high-anchored sheet-pile wall and a relieving platform supported by auger cast-in-place piles. Detailed instrumentation of the dock system was undertaken. The instrumentation included inclinometers, strain gauges and total earth pressure cells on the sheet-pile wall and strain gauges on the anchor rods. Measurements were made over a period of six years to determine deflection, moment and soil pressure on the sheet-piles and tension on tie backs at various stages. The deflections measured in the sheet-pile wall were surprisingly larger than originally calculated. A parametric study was conducted to determine what factors might have been responsible for the large and unexpected deflections. It was concluded that the high deflections were due to the manner in which the backfill was placed and the reduced section modulus: It was determined that the manner in which the sheet-pile was installed did not provide the section modulus as expected. Alternative methods of construction should be examined for future dock construction, which will eliminate the high construction stresses observed in the present project.