Construction method of cutter suction dredger

Dredger

The cutter suction dredger is a watercraft widely used in the field of dredging, desilting and land reclamation. The entire work process can be completed continuously in one go. It is an efficient and low-cost underwater excavation machinery. Below, we will introduce the construction methods of the cutter suction dredger.

Ⅰ.Cross-excavation method

The basic construction method of the cutter suction dredger is the cross-excavation method, which can be further subdivided into the steel pile positioning cross-excavation method and the anchor cable positioning cross-excavation method. The steel pile positioning cross-excavation method uses two steel piles alternately inserted into the riverbed as swing centers and uses the left and right swinging cables at the front of the cutter head to swing the ship back and forth for sand excavation.

When the cutter head swings to the right (left) edge of the excavation groove, the left (right) pile is lowered, and the right (left) pile is raised. At the same time, the right (left) cable is relaxed and the left (right) cable is tightened, causing the cutter head to swing back to the left (right). The distance that the ship moves forward is called the forward distance.

Ⅱ.Main and auxiliary pile method

Due to the two swing centers of the ship's body, there will be overlapping and missing parts in the sand excavation trajectory. In order to overcome this disadvantage, the main and auxiliary pile method (also known as the single pile forward method) can also be used. One steel pile is used as the main pile, and the swing center of the cross-excavation is always the centerline of the excavation groove. Another steel pile is used as an auxiliary pile for forward pile replacement.

Because there is only one dredging swing center, the sand excavation trajectory of the cutter head is parallel to each other. As long as the forward distance of the steel pile is maintained appropriately, over-excavation and under-excavation can be avoided. In order to accurately control the amount of pile replacement, a pair of sightline marks should be added on both sides of the centerline of the excavation groove.

The excavation width of the steel pile cross-excavation method is limited by the length of the ship (including the length of the cutter head extension). According to experience, the excavation width is generally 1.2 to 1.4 times the length of the ship, and the angle between the left and right swing of the dredger and the centerline of the excavation groove should be about 40 degrees. When the excavation width exceeds the excavation width of the cutter suction dredger, it must be constructed in sections.

The above are some construction methods of the cutter suction dredger. We hope it can be helpful to you.