Tutorial Soils

Soils in GEOlib are added in a generic way, this means that there is one basis soil class which is meant to be the input for all the separate D-Serie products. For this reason it is possible that the parameter locations are not as you are used to in the D-Serie products.

Parameters in the Soil class are clustered based on physical meaning. I.e. cohesion and friction angle are clustered in the MohrCoulombParameters class; reloading_swelling_constant_a is stored in the IsotacheParameters class and permeability parameters are stored in the StorageParameters class.

Since parameters are clustered in different classes as the Soil class, it is required to fill in parameters in these respective classes. Below an example is given on how to to initialise a soil with a friction angle and cohesion.

from geolib.soils import Soil, MohrCoulombParameters

mohr_coulomb_parameters = MohrCoulombParameters(cohesion=5, friction_angle=25)
soil = Soil(mohr_coulomb_parameters=mohr_coulomb_parameters)

Another method is to first initialise the soil and then change the values, for example:

from geolib.soils import Soil

soil = Soil()
soil.mohr_coulomb_parameters.cohesion = 5
soil.mohr_coulomb_parameters.friction_angle = 25

Lastly, the parameters can be passed as a dictionary, for example:

from geolib.soils import Soil

kwargs = {"cohesion": 5,
          "friction_angle": 25}
soil = Soil(mohr_coulomb_parameters=kwargs)

When initialising the Soil class all values given should be parameters of the class itself. Otherwise an error is thrown, for example:

from geolib.soils import Soil
soil = Soil(name="Peat", cohesion=0.5)

will result in:

pydantic.error_wrappers.ValidationError: 1 validation error for Soil
cohesion
    extra fields not permitted (type=value_error.extra)

That is because the cohesion value should be set through the mohr_coulomb_parameters parameter. Note that when the Soil class is intialised without the user defining the parameters, it will be populated with default values.

Many parameters can be initialised as either a stochastic variable or a float. When the parameter is filled in as a floating value, the value is automatically translated to a stochastic variable with a mean of the input float and a standard deviation of 0. This step is required to stay consistent in sending parameters to the corresponding models

Below three examples are given on how to input a stochastic variable in the soil.

from geolib.soils import Soil, MohrCoulombParameters, StochasticParameter

cohesion = StochasticParameter(mean=5, standard_deviation=0.5)
mohr_coulomb_parameters = MohrCoulombParameters(cohesion=cohesion)
soil = Soil(mohr_coulomb_parameters=mohr_coulomb_parameters)

from geolib.soils import Soil

soil = Soil()
soil.mohr_coulomb_parameters.cohesion.mean = 5
soil.mohr_coulomb_parameters.cohesion.mean = 0.5

from geolib.soils import Soil

kwargs = {"cohesion":{"mean": 5,
                        "standard_deviation": 0.5}}

soil = Soil(mohr_coulomb_parameters=kwargs)

When the parameters, required for the corresponding model are set, the soil can be added to the soil list of the corresponding model. Note that, for non-filled in parameters, the default value is used. Below an example is given on how to add a soil in D-Settlement. For an overview on how to pass the complete workflow for each model, see the other Tutorials.

from geolib.soils import Soil, MohrCoulombParameters
from geolib.models import DSettlementModel

mohr_coulomb_parameters = MohrCoulombParameters(cohesion=5, friction_angle=25)
soil = Soil(mohr_coulomb_parameters=mohr_coulomb_parameters)

dset_model = DSettlementModel()
dset_model.add_soil(soil)

Certain soil input are enumerations. For example, “soil_type_nl” which is an input for D-Foundations. Below an example is shown on how to set an enumeration for the soil.

from geolib.soils import Soil, SoilType

soil = Soil()
soil.soil_type_nl = SoilType.CLAY

Note that this “SoilType” enumeration is reused for three different soil parameters: “soil_type_nl”, “soil_type_be” and “soil_type_settlement_by_vibrations”. However only “soil_type_nl” accepts SoilType.SANDY_LOAM.