Matters needing attention in dredging construction of cutter suction dredgers

Before the construction of the cutter suction dredger, a control wire is arranged along both sides of the excavated river channel, fixed and eye-catching control piles are set up on each section, the left and right opening lines of the river channel are determined with colored flags of different colors, and the offset value of the center line of the channel. Do not exceed the design requirements. Install a water gauge on the winch rod to control the depth, observe and adjust the dredging depth at any time.

a. Determination of the direction of excavation: In order to analyze the influence of the direction of water flow on the construction efficiency of cutter suction dredgers, excavation tests with forward and reverse currents were carried out during the construction process. The sand content is about 7%-10% (volume ratio, the same below), while the countercurrent excavation is more efficient, with a sand content of 10%-12%, and up to 17%. Moreover, when excavating downstream, due to the pressure of the water flow, the mud delivery pipeline on the water is easy to bend, and the construction is affected to a certain extent; when excavating upstream, the pipeline is unimpeded.

b. Slope excavation: The designed excavation slope is 1:5. According to the technical specification for dredging construction, the stepped excavation method with the lower overhang and the upper undercut is adopted, and the side slope is formed by natural collapse, and the slope ratio is close to 1:4~1:6 between.