Client: Ampol
The innovative pile jack up repair provides a solution to underwater piles needing an extension of design life. The marine borer erodes the piles at seabed level and far more rapidly than rest of the structure, meaning the useful life of the facility is compromised.
The team uses a combination of innovative sonic non-destructive pile condition assessment and underwater inspection to assess and analysis the extent of erosion. The design solution will vary depending on the extent of the erosion and pile design criteria and use of the facility. The underwater pile insitu solutions extend from repair, including the use high strength carbon fibre wrap and reinforcement in combination epoxy or cementitious grout to in-situ replacement with the jack up pile solution.
The jack up pile allows the failed section of pile to be removed and replaced underwater from below seabed, whilst maintaining operational use of the wharf. The solution utilizes the structural capability of the embedded pile.
The jack up solution is economical utilizing relatively light weight equipment. The replacement pile jack up sections can be floated into position and positioned under the wharf with advanced rigging techniques, avoiding the use of traditional heavy barge or wharf cranage and piling equipment or access from above through the wharf deck. Material use is optimized replacing only the damaged section of pile.
Specially designed scour prevention fabric bags filled with cementitious grout are used to reinstate the pile embedment to meet or exceed the capacity of the existing seabed material and protect from future scour and borer attack.
The solution at Ampol has enabled the wharf to be operational throughout the replacement of 80% of the piles in the structure which have been subjected to accelerated borer attack at seabed.
The jack up pile design and method presented here is for timber pile replacement, can be adopted for other forms of structural remediation such as steel or spun pile repairs anywhere in the subsea, tidal zone to deck underside.
