Location

Chicago, Illinois

Session Start Date

4-29-2013

Session End Date

5-4-2013

Abstract

An existing 40 foot diameter sheet pile cell (cell) was used to support a dry fly ash loading platform at an electrical power generating facility on the Ohio River. The cell was designed and constructed in 1986 for support of a coal barge unloading crane but was never put into service. The cell has leaned riverward several inches in the years after construction. Stability analysis indicated a less than adequate overturning factor of safety without any additional loads. The addition of the loading platform could result in an overturning failure. A stabilizing system which provided a horizontal stabilizing force of 750,000 lbs. was developed, designed and subsequently installed. The system included a tension belt steel channel bent about the cell circumference connected to two-1¾inch diameter high strength tension bars at each end. The tension bars extended 100 feet landward and were anchored to two pile caps. The pile caps were supported on a tripod of three-120 ton working load HP14x117 piles driven on a 4:1 batter. The horizontal stabilizing force for the cell originates from four-200 foot long rock anchors (20 foot long bonded length) installed in each pile cap at a nominal angle of 45- degrees from the horizontal. The tension belt channel elongated 3 inches during anchor proof testing while the strand anchors elongated approximately 18 inches. It was necessary to test the anchors in pairs to maintain a balanced loading condition on the tension belt channel, requiring adjusting and balancing the load in the anchors and tension bars continuously to maintain the pile caps in a neutral position. Each anchor proof-test required six hydraulic cylinders and four power packs operated simultaneously at different pressures. After each pair of anchors was proof-tested, the anchors were de-stressed until all pairs had been proof-tested. Then the anchors were reloaded in pairs and locked off at 50% of the 120 ton design load.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Seventh Conference

Publisher

Missouri University of Science and Technology

Publication Date

4-29-2013

Document Version

Final Version

Rights

© 2013 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Apr 29th, 12:00 AM May 4th, 12:00 AM

Stabilization of Existing Sheet Pile Cell in the Ohio River

Chicago, Illinois

An existing 40 foot diameter sheet pile cell (cell) was used to support a dry fly ash loading platform at an electrical power generating facility on the Ohio River. The cell was designed and constructed in 1986 for support of a coal barge unloading crane but was never put into service. The cell has leaned riverward several inches in the years after construction. Stability analysis indicated a less than adequate overturning factor of safety without any additional loads. The addition of the loading platform could result in an overturning failure. A stabilizing system which provided a horizontal stabilizing force of 750,000 lbs. was developed, designed and subsequently installed. The system included a tension belt steel channel bent about the cell circumference connected to two-1¾inch diameter high strength tension bars at each end. The tension bars extended 100 feet landward and were anchored to two pile caps. The pile caps were supported on a tripod of three-120 ton working load HP14x117 piles driven on a 4:1 batter. The horizontal stabilizing force for the cell originates from four-200 foot long rock anchors (20 foot long bonded length) installed in each pile cap at a nominal angle of 45- degrees from the horizontal. The tension belt channel elongated 3 inches during anchor proof testing while the strand anchors elongated approximately 18 inches. It was necessary to test the anchors in pairs to maintain a balanced loading condition on the tension belt channel, requiring adjusting and balancing the load in the anchors and tension bars continuously to maintain the pile caps in a neutral position. Each anchor proof-test required six hydraulic cylinders and four power packs operated simultaneously at different pressures. After each pair of anchors was proof-tested, the anchors were de-stressed until all pairs had been proof-tested. Then the anchors were reloaded in pairs and locked off at 50% of the 120 ton design load.