About Positioning Steel Piles of Cutter Suction Dredger
The cutter suction dredger is equipped with two positioning steel piles on both sides of its tail end. The positioning steel pile and winch anchor cable system work together to achieve accurate positioning of dredging operations, as well as the lateral and forward movement of the cutter head and the hull, ensuring that dredging operations proceed along a certain trajectory.
The entire pile body of the positioning steel pile is formed by bending steel plates into a tubular shape and welding, and small positioning steel piles are also made directly from seamless steel pipes. The top of its lower end is equipped with a conical cast steel pile head to facilitate the positioning of the steel pile and its insertion into the underwater soil layer. Some are still pouring cement into the pile body, with inlet and outlet holes at the lower end to increase the weight of the positioning pile itself. Positioning steel piles are generally installed in clamps on both sides of the tail end wall of the dredger; Alternatively, it can be installed on the positioning pile trolley in the groove at the tail and fixed with clamps to prevent the positioning steel pile from swinging.
(1) Structure for positioning steel pile heads
In order to facilitate the insertion of steel piles into underwater soil layers and adapt to the insertion of various hardness mud and sand layers underwater, there are various forms and structures of steel pile heads.
(2) Steel Pile Materials and Welding
Steel pile materials are generally made of high-strength welded structural steel, and the properties of the steel are shown in Table below
| Material No | Tensile Strength MPa |
Yield Strength MPa |
| SM50 | 500～620 | >300 |
| SM58 | 580～730 | >440 |
(3) Steel pile strength
According to various known conditions, calculate the force on steel piles under different working conditions (such as excavation depth, wind direction, flow direction, and operation), and take the maximum force for steel pile strength verification. When working in coastal areas with surging waves, some designs also take into account the effects of wave forces and the three-dimensional periodic motion of the hull caused by waves on the steel piles (the latter is mainly based on model experiments).
