The Delft Sand, Clay & Rock Cutting Model, 2019a

Exercises.
16.6. Chapter 6: Water Saturated Sand Cutting.
16.6.1. MC: Soil Mechanical Parameters.
Which of the following soil mechanical parameters play a dominant role in the cutting of saturated sand?
The bold green answers are true.
1. The density of water.
2. The angle of internal friction.
3. The permeability of the sand.
4. The tensile strength of the sand.
5. The porosity of the sand.
6. The adhesion of the sand.
7. The angle of external friction of the sand.
8. The shear strength of the sand.
16.6.2. MC: Dilatation.
What is the definition of dilatation?
The bold green answers are true.
1. Dilatation is the increase of the pore volume of sand caused by gravitation.
2. Dilatation is the decrease of the pore volume of sand caused by shear stress.
3. Dilatation is the decrease of the pore volume of sand caused by dredging.
4. Dilatation is the increase of the pore volume of sand caused by shear stress.
5. Dilatation is the increase of the pore volume of sand caused by dredging.
6. Dilatation is the decrease of the pore volume of sand caused by gravitation.
16.6.3. MC: Cavitation.
Which statements are true?
The bold green answers are true.
1. Cavitation is in fact the boiling of water.
2. Cavitation at 10 degrees centigrade occurs at about 0.1 bar absolute pressure.
3. At 100 degrees centigrade cavitation will occur at about 100 kPa.
4. Cavitation is the vaporization of water.
5. Cavitation at 10 degrees centigrade occurs at about 0.01 bar absolute pressure.
6. High in the mountains cavitation will occur at a temperature lower than 100 degrees centigrade.
7. At an atmospheric pressure of 100 kPa cavitation occurs at 10 degrees centigrade.
8. High in the mountains cavitation will occur at a temperature higher than 100 degrees centigrade.
16.6.4. Calc.: Porosity.
If the porosity of sand is 42% before cutting (in situ) and 50% after cutting, what is the volume increase of
the sand (grains + pores) as a fraction?
n n 0.5 0.42
0.16
1 n 1
0.5
max i
max
16.6.5. Calc. : Density.
Assume a water density of 1.000 ton/m 3 and a quarts density of 2.650 ton/m 3 . What is the density of a sand
with a porosity of 40% (saturated sand)?
1 n n 1 0.4 2.65 0.41.00 1.99
(ton/m 3 )
s q w
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