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

The Delft Sand, Clay & Rock Cutting Model.
16.6.6. Calc.: Permeability.
What is the value of the mean permeability km as used in the cutting equations for water saturated sand?
Consider a sand with the following properties:
Initial permeability: k i=0.0001 m/sec
Maximum permeability: k max=0.0004 m/sec
ki
kmax
0.0001
0.0004
km
0.00025 (m/sec)
2 2
16.6.7. Calc.: Dilatancy.
What is the value of the dilatancy ε?
Consider a sand with the following properties:
initial porosity: n i=40%
Maximum porosity: n max=50%
nmax
ni
0.5 0.4
0.20
1
n 1
0.5
max
(-)
16.6.8. Calc.: Transition Velocity.
Give the equation for the transition velocity from non-cavitating cutting to cavitating cutting.
v
c
d z 10 k
c h
1 m
1 i
16.6.9. Calc.: Cutting Forces & Specific Energy.
Consider a sand with the following properties:
Angle of internal friction: φ=36º
Angle of external friction: δ=24º
Initial permeability: k i=0.00005 m/sec
Maximum permeability: k max=0.00025 m/sec
initial porosity: n i=42%
Maximum porosity: n max=50%
The cutting blade has the following properties:
The cutting angle: α=60º
The shear angle: β=20º
The blade height: h b=0.2 m
The thickness of the layer to be cut: h i=0.1 m
The width of the blade: w=1 m
Coefficients for the cutting equations:
The coefficient for non-cavitating cutting: c 1=0.35
The coefficient for cavitating cutting: d 1=4.5
General constants:
The density of water: ρ w=1.025 tons/m 3
The gravitational constant: g=9.81 m/sec 2
A: What are the horizontal cutting forces at 0 m, 15 m and 30 m water depth for the non-cavitational cutting
process at a cutting velocity of 0.5 m/s?
Page 410 of 454 TOC Copyright © Dr.ir. S.A. Miedema