The clayey soil containing calcareous nodules has unique characteristics of pipeline hydraulic transportation. In order to avoid pipeline blockage, effective engineering and technical measures can be adopted by CSD.
1) When using high-concentration mud pipeline transportation, the difference of dredged soil quality should be fully taken into account, and relevant construction parameters should be reasonably determined and controlled according to the transport characteristics of different soil materials.
2) Calcareous nodules and hard plastic clay are prone to pipe blockage during pipeline transportation. Pipe blockage can be solved by increasing the transportation velocity to 4.8m/s and controlling the concentration below 20%
3) When calcareous nodules and hard plastic clay block the pipeline, it is better to use water flashing from the reverse direction which is proven an effective method;
4) For the problems of difficult pipeline laying, long construction time, and easy wear and leakage, it is necessary to further explore the use of new pipeline materials and underwater mud discharge pipeline laying process and CSD on the basis of summarizing successful field experience.
