Introduction Dredging Engineering: OE4607

In dredging, trenching, (deep sea) mining, drilling, tunnel boring and many other applications, sand, clay or rock has to be excavated. The productions (and thus the dimensions) of the excavating equipment range from mm3/sec - cm3/sec to m3/sec. In oil drilling layers with a thickness of a magnitude of 0.2 mm are cut, while in dredging this can be of a magnitude of 0.1 m with cutter suction dredges and meters for clamshells and backhoe’s. Some equipment is designed for dry soil, while others operate under water saturated conditions. Installed cutting powers may range up to 10 MW. For both the design, the operation and production estimation of the excavating equipment it is important to be able to predict the cutting forces and powers. After the soil has been excavated it is usually transported hydraulically as a slurry over a short (TSHD’s) or a long distance (CSD’s) or mechanically. Estimating the pressure losses and determining whether or not a bed will occur in the pipeline is of great importance. Fundamental processes of sedimentation, initiation of motion and erosion of the soil particles determine the transport process and the flow regimes. In TSHD’s the soil has to settle during the loading process, where also sedimentation and erosion will be in equilibrium. In all cases we have to deal with soil and high density soil water mixtures and its fundamental behavior. The lecture notes are complemented with the book The Delft Sand, Clay & Rock Cutting Model, by Dr.ir. Sape A. Miedema and available at www.iospress.nl. Additional information can be found on www.delftdredging.com, www.dredgingengineering.com, www.dhlldv.com and www.dscrcm.com.