Earth pressure

Earth pressure models

class actions.earth_pressure.earth_pressure.EarthPressureBase(zGround, gammaSoil)

Bases: actions.earth_pressure.earth_pressure.PressureModelBase

Parameters to define a load of type earth pressure

Variables:
  • zGround – global Z coordinate of ground level
  • gammaSoil – weight density of soil
class actions.earth_pressure.earth_pressure.EarthPressureModel(zGround, zBottomSoils, KSoils, gammaSoils, zWater, gammaWater, qUnif=0)

Bases: actions.earth_pressure.earth_pressure.PressureModelBase

Parameters to define a load of type earth pressure

Variables:
  • zGround – global Z coordinate of ground level
  • zBottomSoils – list of global Z coordinates of the bottom level for each soil (from top to bottom)
  • KSoils – list of pressure coefficients for each soil (from top to bottom)
  • gammaSoils – list of weight density for each soil (from top to bottom)
  • zWater – global Z coordinate of groundwater level (if zGroundwater<minimum z of model => there is no groundwater)
  • gammaWater – weight density of water
  • qUnif – uniform load over the backfill surface (defaults to 0)
getPressure(z)

Return the earth pressure acting on the points at global coordinate z.

class actions.earth_pressure.earth_pressure.EarthPressureSlopedWall(Ksoil, gammaSoil, zGroundPnt1, XYpnt1, zGroundPnt2, XYpnt2)

Bases: object

Earth pressure on a sloped wall. A single soil type with no freatic is considered.

Variables:
  • Ksoil – pressure coefficient of the soil
  • gammaSoil – weight density of the soil
  • zGroundPnt1 – global Z coordinate of ground level at point of coordinates XYpnt1
  • XYpnt1 – (x,y) coordinates of point 1
  • zGroundPnt2 – global Z coordinate of ground level at point of coordinates XYpnt2
  • XYpnt2 – (x,y) coordinates of point 2
appendLoadToCurrentLoadPattern(xcSet, vDir)
getPressure(x, y, z)
class actions.earth_pressure.earth_pressure.HorizontalLoadOnBackfill(soilIntFi, qLoad, zLoad, distWall, widthLoadArea, lengthLoadArea=1, horDistrAngle=0)

Bases: actions.earth_pressure.earth_pressure.PressureModelBase

Lateral earth pressure on a retaining wall due to a surcharge load acting in horizontal direction on the backfill.

Variables:
  • soilIntFi – agle of internal friction of the soil (º)
  • qLoad – surcharge load (force per unit length)
  • zLoad – global Z coordinate where the line load acts
  • distWall – minimal horizontal distance between the wall and the area where the surcharge load acts (e.g.: a foundation)
  • widthLoadArea – width (perperdicular to wall) of the area on which the horizontal load acts (e.g.: a foundation).
  • lengthLoadArea – width (parallel to wall) of the area on which the horizontal load acts (e.g.: a foundation). We can take lengthLoadArea=1 (default) for a continous load
  • horDistrAngle – angle to distribute load in the direction of the lengthLoadArea (defaults to 0 to apply all the load to a length of wall =lengthLoadArea, which would be the case of a continous load)
appendLoadToCurrentLoadPattern(xcSet, vDir, iCoo=2, delta=0.0)

Append to the current load pattern the earth thrust on a set of elements due to the horizontal load.

Parameters:
  • xcSet – set that contains the elements (shells and/or beams)
  • vDir – unit xc vector defining pressures direction
getMaxMagnitude()

Return the maximum magnitude of the vector loads

getPressure(z)

Return the earth pressure acting on the points at global coordinate z

setup()

Calculate basic parameters

class actions.earth_pressure.earth_pressure.LineVerticalLoadOnBackfill(qLoad, zLoad, distWall)

Bases: actions.earth_pressure.earth_pressure.PressureModelBase

Lateral earth pressure on a retaining wall due to line surcharge load acting in vertical direction on the backfill. (J.Calavera, pg.41)

Variables:
  • qLoad – surcharge load (force per unit length)
  • zLoad – global Z coordinate where the line load acts
  • distWall – horizontal distance between the wall and the line surcharge load
getMaxMagnitude(xcSet)

Return an estimation of the maximum magnitude of the vector loads (it’s supposed to occur in a point placed 1/3L from the top)

getPressure(z)

Return the earth pressure acting on the points at global coordinate z

class actions.earth_pressure.earth_pressure.MononobeOkabePressureDistribution(zGround, gamma_soil, H, kv, kh, psi, phi, delta_ad, beta, Kas)

Bases: actions.earth_pressure.earth_pressure.EarthPressureBase

Overpressure due to seismic action according to Mononobe-Okabe

Variables:
  • H – height of the structure.
  • kv – seismic coefficient of vertical acceleration.
  • kh – seismic coefficient of horizontal acceleration.
  • psi – back face inclination of the structure (< PI/2)
  • phi – angle of internal friction of soil.
  • delta_ad – angle of friction soil - structure.
  • beta – slope inclination of backfill.
  • Kas – static earth pressure coefficient
getPressure(z)

Return the earth pressure acting on the points at global coordinate z

update()
class actions.earth_pressure.earth_pressure.PeckPressureEnvelope(phi, zGround, gammaSoil, zWater, gammaWater, H)

Bases: actions.earth_pressure.earth_pressure.EarthPressureBase

Envelope of apparent lateral pressure diagrams for design
of cuts in sand. See 10.2 in the book “Principles of Foundation Engineering” from Braja M. Das.
Variables:
  • H – height of the cut.
  • phi – effective friction angle of sand.
getPressure(z)

Return the earth pressure acting on the points at global coordinate z.

class actions.earth_pressure.earth_pressure.PressureModelBase

Bases: object

Basse class for objects defining earth pressures.

appendLoadToCurrentLoadPattern(xcSet, vDir, iCoo=2, delta=0.0)

Append earth thrust on a set of elements to the current load pattern.

Parameters:
  • xcSet – set that contains the elements (shells and/or beams)
  • vDir – unit xc vector defining pressures direction
  • iCoo – index of the coordinate that represents depth.
  • delta – soil-wall friction angle (usually: delta= 2/3*Phi).
getPressure(z)

Return the earth pressure acting on the points at global coordinate z.

class actions.earth_pressure.earth_pressure.StripLoadOnBackfill(qLoad, zLoad, distWall, stripWidth)

Bases: actions.earth_pressure.earth_pressure.UniformLoadOnStem

Lateral earth pressure on a retaining wall due to a strip surcharge load on the backfill. (J.Calavera, pg.40)

Variables:
  • zLoad – global Z coordinate where the surcharge load acts
  • distWall – minimal horizontal distance between the wall and the surcharge load
  • stripWidth – width of the strip
  • coef – is a coefficient = 1.5 (default) for the usual case of non-rigid walls. It can be redefined =2 for rigid walls
appendVerticalLoadToCurrentLoadPattern(xcSet, vDir, iXCoo=0, iZCoo=2, alph=0.5235987755982988)
Append to the current load pattern the vertical pressures on
a set of elements due to the strip load. According to 11.3.4 in the book “Mecánica de suelos” of Llano, J.J.S. isbn= 9788471461650 (https://books.google.ch/books?id=oQFZRKlix_EC)
Parameters:
  • xcSet – set that contains the elements.
  • vDir – unit xc vector defining pressures direction
  • alph – angle of stress spreading.
getMaxMagnitude(xcSet)

Return an estimation of the maximum magnitude of the vector loads (it’s supposed to occur in a point placed 1/3L from the top)

getPressure(z)

Return the earth pressure acting on the points at global coordinate z

class actions.earth_pressure.earth_pressure.UniformLoadOnBackfill(K, qLoad)

Bases: actions.earth_pressure.earth_pressure.UniformLoadOnStem

Lateral earth pressure on a retaining wall due to a uniform indefinite
load on the backfill.
Variables:qLoad – surcharge load (force per unit area)
getPressure(z)

Return the earth pressure acting on the points at global coordinate z.

class actions.earth_pressure.earth_pressure.UniformLoadOnStem(qLoad)

Bases: actions.earth_pressure.earth_pressure.PressureModelBase

Uniform lateral earth pressure on a retaining wall.

Variables:qLoad – surcharge load (force per unit area)
getPressure(z)

Return the earth pressure acting on the points at global coordinate z.