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3.10: Nomenclature

  • Page ID
    33412
  • a1, a2

    Coefficients for weighted permeability

    -

    a, \(\ \tau_\mathrm{a}\)

    Adhesion or external shear strength

    kPa

    A

    Adhesive force on the blade

    kN

    c, \(\ \tau_\mathrm{c}\)

    Cohesion or internal shear strength

    kPa

    C, C1

    Force due to cohesion in the shear plane

    kN

    C2

    Force due to cohesion on the front of the wedge

    kN

    C3

    Force due to cohesion at the bottom of the wedge

    kN

    Fh

    Horizontal cutting force

    kN

    Ff1

    Friction force on the shear surface

    kN

    Ff2

    Friction force on the blade

    kN

    Fn1

    Normal force on the shear surface

    kN

    Fn2

    Normal force on the blade

    kN

    Fv

    Vertical cutting force

    kN

    Fd1

    Deviation force on the shear surface

    kN

    Fd, d2

    Deviation force on the blade

    kN

    Fx1, 2

    Cutting force in x-direction

    kN

    Fy1, 2

    Cutting force in y-direction

    kN

    Fz1, 2

    Cutting force in z-direction

    kN

    g

    Gravitational constant (9.81)

    m/s2

    G, G1

    Gravitational force on the layer cut

    kN

    G2

    Gravitational force on the wedge

    kN

    hi

    Initial thickness of layer cut

    m

    hb

    Height of blade

    m

    hb,m

    Effective height of the blade in case Curling Type

    m

    I

    Inertial force on the shear plane

    kN

    ki

    Initial permeability

    m/s

    kmax

    Maximum permeability

    m/s

    km

    Average permeability

    m/s

    K1

    Grain force on the shear plane

    kN

    K2

    Grain force on the blade or the front of the wedge

    kN

    K3

    Grain force on the bottom of the wedge

    kN

    K4

    Grain force on the blade (in case a wedge exists)

    kN

    ni

    Initial porosity

    %

    nmax

    Maximum porosity

    %

    N1

    Normal force on the shear plane

    kN

    N2

    Normal force on the blade or the front of the wedge

    kN

    N3

    Normal force on the bottom of the wedge

    kN

    N4

    Normal force on the blade (in case a wedge exists)

    kN

    p1m

    Average pore pressure on the shear surface

    kPa

    p2m

    Average pore pressure on the blade

    kPa

    Pc

    Cutting power

    kW

    R1

    Acting point of resulting forces on the shear plane

    m

    R2

    Acting point of resulting forces on the blade

    m

    R3

    Acting point of resulting forces on the bottom of the wedge

    m

    R4

    Acting point of resulting forces on the blade (in case a wedge exists)

    m

    S1 

    Shear force due to friction on the shear plane

    kN

    S2 

    Shear force due to friction on the blade or the front of the wedge

    kN

    S3 

    Shear force due to friction at the bottom of the wedge

    kN

    S4 

    Shear force due to friction on the blade (in case a wedge exists)

    kN

    vc 

    Cutting velocity component perpendicular to the blade

    m/s

    vd 

    Cutting velocity, drag velocity

    m/s

    vr1 

    Velocity of grains in the shear surface

    m/s

    vr2 

    Relative velocity of grains on the blade

    m/s

    vd1 ​​​​​​​

    Deviation velocity of grains in the shear surface

    m/s

    vd2 ​​​​​​​

    Deviation velocity of grains on the blade

    m/s

    vx1,2

    Velocity of grains in the x-direction

    m/s

    vy1,2

    Velocity of grains in the y-direction

    m/s

    vz1,2

    Velocity of grains in the z-direction

    m/s

    W Width of blade m
    W1 Force resulting from pore under pressure on the shear plane

    kN

    W2 Force resulting from pore under pressure on the blade/ front wedge

    kN

    W3 Force resulting from pore under pressure on the bottom of the wedge kN
    W4 Force resulting from pore under pressures on the blade, wedge kN
    Z Water depth m

    \(\ \alpha\)

    Cutting angle blade

    rad

    β

    Shear angle

    rad

    ε

    Dilatation

    -

    φ

    Angle of internal friction

    rad

    φe

    Angle of internal friction perpendicular to the cutting edge

    rad

    λs

    Strengthening factor

    -

    λ1 

    Acting point factor for resulting forces on the shear plane

    -

    λ2 

    Acting point factor for resulting forces on the blade or front of wedge

    -

    λ3 

    Acting point factor for resulting forces on the bottom of the wedge

    -

    λ

    Acting point factor for resulting forces on the blade

    -

    δ

    External friction angle

    rad

    δe

    External friction angle perpendicular to the cutting edge

    rad

    \(\ \iota\)

    Deviation angle blade

    rad

    ρs

    Density of the soil

    ton/m3

    ρl

    Density water

    ton/m3

    θ

    Wedge angle

    rad

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