The extension of the harbor at the Shekou docks in Shenzhen required the extraction of twenty year old ThyssenKrupp sheet piles. The 24m long sheet piles were encapsulated in a brick wall and after such an extended period in the ground bearing such heavy loads were stuck firmly in the soil. After failing with a long line of electric and hydraulic extracting equipment the client chose the powerful ICE 1412C vibratory hammer to extract the piles.
 
Vibratory hammers generate vibrations to overcome soil friction and extract a pile. At the site in Shekou the soil layer at minus 12-18m was made up of silty clay. This type of soil requires a hammer with high frequency to set the pile in motion and overcome the soil friction. Once the pile is in motion the hammer must keep on going in order not to keep hanging in the clay layers. The 1412C’s cooling system allowed the hammer to work without interruption and extract the pile in one motion. Besides these difficult soil conditions, extracting a sheet pile that has been in the soil for twenty years poses a lot of extra challenges. The shear from the compacted soil requires a great force to overcome the soil friction, but as these piles were exposed to seawater, and some interlocks were rusted or corroded making the piles vulnerable to breaking, the power of the vibro needs to be dosed very carefully to extract the pile in one piece.
 
Because the sheet piles were type 5, the clamp width of the 320TU exceeded the width of the sheet pile. ICE clamps are carefully paired with each hammer type, as we guarantee the clamps clamping force exceeds the hammers maximum eccentric forces to ensure safe operation. The client decided to fit the piles to the clamp by cutting off one side of the sheet pile allowing sufficient space for the jaws to get a proper grip on the sheet pile. Not only did the 1412C not break the piles like other hammers did, it also enabled the client to on average extract 12 sheet piles a day (whereas previously they managed 3-6 a day at most), seeing the job to completion within 6 weeks and ahead of schedule.
 
The majority of the Arcelor sheet piles came up as good as new showing few signs of wear, ready for reuse. ICE has 40 years of experience building reliable vibratory hammers and clamping systems to get your job done.