pypassive package

Submodules

pypassive.alqarawi_et_al_2021 module

class pypassive.alqarawi_et_al_2021.AlqarawiLogSpiral(soil_layer, retaining_wall)[source]

Bases: object

Compute passive pressure on retaining wall. ref: Alqarawi, A. S., Leo, C. J., Liyanapathirana, D. S., Sigdel, L., Lu, M., and Hu, P. (2012). A spreadsheet-based technique to calculate the passive soil pressure based on log-spiral method. Computers and Geotechnics 130.

calc_Mabg() → float[source]
calc_Magfp()[source]
calc_Moba() → float[source]
calc_Mobg() → float[source]
calc_Mq() → float[source]
calc_Mqh() → float[source]
calc_Mrw() → float[source]
calc_afp() → None[source]
calc_alpha1() → float[source]

Eq 1

calc_alpha2() → float[source]

Eq 2

calc_coords(zeta: float) → None[source]

Coordinates that define salient points

calc_kp() → float[source]

Rankine’s passive pressure coefficient for sloped backfill.

calc_l1(zeta: float) → float[source]
calc_moments() → None[source]
calc_passive_force_all(zeta: float) → float[source]

Determine the total passive force from moment equilibrium.

passive_force() → float[source]

Minize the passive force by changing, zeta, the center of the log spiral

pypassive.douglasdavis module

class pypassive.douglasdavis.DouglasDavis1964(soillayer, foundation)[source]

Bases: object

Deflection at upper (y1) and lower (y2) corners of the horizontally loaded rectangular area

Elasticity solution for horizontal loading on a vertical rectangle. Douglas, D. J., and Davis, E. H. (1964). Geotechnique Vol. 14(3), p 115-132

Parameters:

load (float) – Total horizontal load on the rectangular area

Returns Tuple():

A tuple of floats of corner deflections.

calc_c1c2() → Tuple[float, float][source]

Dimensions are defined in the Mokwa (1999) pg. 269

Returns:

Surface surcharge adjust distances to the bottom and top of the foundation.

Return type:

Tuple()

calc_influence_factors() → Tuple[float, float, float, float, float, float, float][source]

Influence factors equations are given in Mokwa (1999), appendix H, eqn. H.3 to H.7, pg. 380 - 381. I1 and I2 are combinations of influence factors required for calculating y1 at the top corners, and y2 at the bottom corners.

Returns Tuple():

A tuple of floats of influence factors (f1, f2, f3, f4, f5, I1, I2)

calc_kmax(load: float = 1) → float[source]

Initial elastic stiffness, based on ultimate load and average corner deflections.

Parameters:

load (float) – applied force

Returns float:

intial elastic stiffness

corner_deflections(load: float = 1) → Tuple[float, float][source]

Deflection at upper (y1) and lower (y2) corners of the horizontally loaded rectangular area

Parameters:

load (float) – Total horizontal load on the rectangular area

Returns Tuple():

A tuple of floats of corner deflections.

property influence_factors

Returns a dict key and value.

property kmax

pypassive.duncanmokwa_logspiral module

class pypassive.duncanmokwa_logspiral.DuncanMokwaLogSpiral(soil_layer, foundation)[source]

Bases: object

Compute passive pressure on retaining wall. ref: Mokwa, R. L. (1999). Investigation of Resistance of Pile Caps to Lateral Loading. Duncan, M. J., and Mokwa, R. L. (2001). Passive Earth Pressures: Theories and Tests

property Ep: float

The ultimate passive pressure.

property Eprc: None

Rankine passive earth pressure due to cohesion.

property Eprphi: None

Rankine passive earth pressure due to soil weight and friction angle.

property Eprq: None

Rankine passive earth pressure due to surface surcharge.

property Ppc: float

Passive force component due to soil cohesion.

property Ppphi: float

Passive force component due to soil weight and friction.

property Ppq: float

Passive force component due to surface surcharge.

property alpha: float

Passive failure angle with the horizontal

calc_Ep(w: float) → float[source]

Ultimate passive earth pressure Eqn F.1

Parameters:

w – the length of the failure surface on the ground

Type:

float

calc_Eprc() → float[source]

Rankine earth pressure due to cohesion acting on the vertical face in the Rankine region Eqn F.10

Returns:

Rankine earth pressure due to cohesion acting on the vertical face in the Rankine region

Return type:

float

calc_Eprphi() → float[source]

Rankine earth pressure due to soil weight, Eqn F.6

Returns:

Rankine earth pressure due to friction and soil weight

Return type:

float

calc_Eprq() → float[source]

Rankine earth pressure due to surcharge in the Rankine region F.13

Returns:

Rankine earth pressure due to surcharge

Return type:

float

calc_Mc() → float[source]

Moment due to cohesion about point O Eqn. F.11

Returns:

moment due to cohesion

Return type:

float

calc_Ppc() → float[source]

Earth pressure due to cohesion, Eq F.12

Returns:

Earth pressure due to cohesion

Return type:

float

calc_Ppphi() → float[source]

Earth pressure due to self weight of the soil and friction angle Eqn F.7

Returns:

Passive force from self weight and friction angle

Return type:

float

calc_Ppq(w: float) → float[source]

Passvive force at the wall face due to surface surcharge Eqn F.14

Returns:

Passive force due to surface surcharge

Return type:

float

calc_Rankine_passive_earth_pressures() → None[source]

Compute Rankine passive earth pressures

calc_diagonal_dist(w: float, xo: float) → float[source]

Compute, the diagonal distance from the log spiral center to the end of the log spiral Eq F.3.g

Parameters:

  • w – length of the failure surface on the ground surface

  • xo – abscissa of the log spiral center

Type:

float

Type:

float

Returns:

r, the diagonal distance from the log spiral center to the end of the log spiral

Return type:

float

calc_hd1(w: float) → float[source]

Calculate the height of Rankine earth presssure region behind the log spiral region. during log spiral radius minimization, Eq. F.3.c

Parameters:

w – length of the failure region on the surface

Type:

float

Returns:

hd, the height of the Rankine earth pressure region

Return type:

float

calc_hd2() → float[source]

Calculate the height of Rankine earth presssure region behind the log spiral region, after log spiral radius minimization. Eq. F.4.a

Returns:

hd, the height of the Rankine earth pressure region

Return type:

float

calc_l1() → float[source]

Vertical moment arm of the passive force, Ppphi, from the log spiral center, l1. F.4.b

Returns:

l1, moment arm l1

Return type:

float

calc_l2(w: float) → float[source]

Moment arm of the log spiral weight from the log spiral center, l2. Eqn F.4.d

Parameters:

w – the length of the failure surface on the ground

Type:

float

Returns:

moment arm l2

Return type:

float

calc_l3() → float[source]

Moment arm of the Rankine passive force from friction, from passive region behind the log spiral region, l3. Eqn F.4.e

Returns:

moment arm l3

Return type:

float

calc_l4(w: float) → float[source]

Moment arm of the surcharge force from the log spiral center, l4. Eq F.8

Parameters:

w – the length of the failure surface on the ground

Type:

float

Returns:

moment arm l4

Return type:

float

calc_l5() → float[source]

Moment arm of Rankine passive force from cohesion, from passive region behind the log spiral region. Eq F.9

Returns:

moment arm l5

Return type:

float

calc_log_spiral_r() → float[source]

Compute, log spiral radius at any angle theta from ro. Eq F.2

Returns:

r, log spiral radius

Return type:

float

calc_log_spiral_ro(xo: float) → float[source]

Compute, ro, the starting radius of the log spiral. Eq F.3.e

Parameters:

xo – abscissa of the log spiral center

Type:

float

Returns:

ro, initial radius of the log spiral

Return type:

float

calc_log_spiral_theta(xo: float) → float[source]

Compute, log spiral angle theta. Eq F.3.f

Parameters:

xo – abscissa of the log spiral center

Type:

float

Returns:

theta, log spiral angle

Return type:

float

calc_log_sprial_soil_weight(w: float) → float[source]

Compute the weight of the log spiral region Eqn F.5

Parameters:

w – lenght of the failure surface on the ground

Type:

float

Returns:

the weight of the log spiral

Return type:

float

calc_moment_arms(w: float) → None[source]

Compute remaining quantities and moment arms after determing log spiral radius from minimization

calc_r(xo: float, w: float) → float[source]

Adjust the center of the log spiral such that the diagonal distance and the log spiral radius at the end of the log spiral are equal, i.e. minimize abs(log_spiral_r - r)

Parameters:

  • xo – abscissa of the origin of the log spiral

  • w – length of the failure surface on the ground surface

Type:

float

Type:

float

Returns:

r, the distance from the log spiral center to the end of the log spiral

Return type:

float

calc_yo(xo: float) → float[source]

Compute ordinate of the log spiral center. Eq. F.3.d

Parameters:

xo – abscissa of the log spiral ordinate.float = 5 * self._h

Type:

float

Returns:

yo, ordinate of the log spiral center.

Return type:

float

property hd: float

The vertical height of the Rankine passive earth pressure region behind the log spiral region.

property l1: float

Vertical moment arm of the passive force, Ppphi, from the log spiral center.

property l2: float

Moment arm of the log spiral weight from the log spiral center.

property l3: float

Moment arm of the Rankine passive force from friction, from passive region behind the log spiral region.

property l4: float

Moment arm of the surcharge force from the log spiral center.

property l5: float

Moment arm of Rankine passive force from cohesion, from passive region behind the log spiral region.

property log_spiral_weight: float

The weight of the soil in the log spiral region

passive_force() → Any[source]
property r: float

Log spiral radius

property ro: float

Log spiral initial radius

property theta: float

Angle of the log spiral

property w: float

The width of the log spiral along the surface.

property xo: float

The horizontal distance of the log spiral center from the wall.

property yo: float

The vertical distance of the log spiral center from the top of the wall.

pypassive.mokwaduncan_hyperbolic module

class pypassive.mokwaduncan_hyperbolic.MokwaDuncanHyperbolic(pult: float = 0, kmax: float = 1, delta_max: float = 1, rf: float = None)[source]

Bases: object

Influence factors for computing the deflection of horizontally loaded vertical rectangle. ref: Mokwa, R. L. (1999). Investigation of the Resistance of Pile Caps to Lateral Loading.

Use consistent units for calculations and adjust the units in postprocessing the results.

calc_rf() → float[source]
Failure ratio as defined in Duncan and Change (1970). The ratio of the asymptotic

stress of the hyperbolic curve to the soil strength.

Returns float:

Failure ratio

hyperbolic_force_displacement(ys: Any = []) → Any[source]

Hyperbolic force-displacement curve.

Parameters:

  • ys (Any) – horizontal displacements

  • pult (float) – Failure load

  • dmax_height_ratio (Any) – Ratio of the assumed displacement at failure to the height of the rectangular area (footing depth, retaining wall height).

pypassive.soil module

class pypassive.soil.RetainingWall(height: float, width: float = 1, depth: float = 0, omega: float = 0, backfill_surcharge: float = 0, backfill_slope: float = 0)[source]

Bases: object

property b
property beta
property h
property omega
property q
property z
class pypassive.soil.SoilLayer(c: float, phi: float, unit_weight: float = 120, delta: float = None, modE: float = 600000, nu: float = 0.5, alphac: float = 0.0, surcharge: float = 0)[source]

Bases: object

Class for soil layer, with layer properties.

property alphac
property c
property delta
property gamma
property modE
property nu
property phi
property q

pypassive.utility_functions module

pypassive.utility_functions.ovesen_3D_effects_correction(phi: float, width: float, height: float, depth: float, spacing: float)[source]

Ovesen-Brinch Hansen Method of correcting for 3D Effects in Passive Earth Pressures.

Parameters:

  • phi (float) – Mohr-Coulomb phi parameter, soil friction angle, degrees

  • width (float) – Width of the foundation/retaining wall.

  • height (float) – Height of the foundation/retaining wall.

  • depth (float) – Distance from the top of the soil layer to the top of the foundation/retaining wall.

  • spacing (float) – If multiple close-by footing or retaining wall

pypassive.utility_functions.rankine_passive_pressure_coeff(phi: float, c: float) → float[source]

Compute Rankine earth pressure coefficient. Use consistent units :param phi: Mohr-Column phi parameter, friction angle in degrees :type: float :param c: Mohr-Column c parameter, cohesion in F/L^2 :type: float :param height: wall height in units of length, L :type: float :param gamma: unit weight of the soil in F/L^3 :type: float :return: kp, coefficient of passive earth pressure :rtype: float

Module contents