Soil Types

The Soil Types tab is used to define the soil types found within the profile. If the soil properties are to be varied, then all layers for a given soil type are varied by the same amount. The following group boxes are found on this tab.

Note: The Non-Linear Curve Variation Parameters group box is only shown when the variation of non-linear parameters is enabled.

Soil Types

Name
The name of the soil used in drop down boxes to select the soil type and in printing of output.
Unit Weight
The unit weight of the soil used in the dynamic response of the system.
Initial Damping
The initial estimate of the material damping. This damping is used in the first iteration of the equivalent-linear site response analysis.
G/G$_{max}$ Model
The model used for the shear-modulus reduction.
Damping Model
The model used for the material damping.
Notes
The notes are only present to preserve one's sanity and are not used in any way.
Varied
The varied check box allows the non-linear properties of some layers not to be varied. This check box is only shown if variation of the non-linear soil properties is enabled.

Bedrock Layer

Basic properties of the half-space layer. The damping of the half-space layer does not change with strain so a good estimate of damping is important. The variation of the damping in the half-space layer is governed by the same model as all of the other soil types.

Darendeli and Stokoe Model Parameters

When the Darendeli & Stokoe model is selected for either the shear modulus reduction or material damping curve thie group box will become enabled. This properties are used to compue the Darendeli and Stokoe non-linear curves.

Non-Linear Property

Allows for editting of the non-linear property curves. If you want to make the curve permanent for use in other prrojects considering adding the curve to the library with the Non-Linear Curve Dialog.

Non-Linear Curve Variation Parameters

The non-linear properties are varied assuming a normal distribution with the provided values as the mean. The standard deviation can be computed using the Darendeli and Stokoe model, or a custom model. Regardless of the model it is required that the maximum and minium normalized shear modulus and minimum material damping values be considered and defined. Strata prevents the user from defined a shear modulus reduction less than 0.05 and a damping less than 0.01%.

When defining a custom model, the user can use a wide variety of functions and variables. In the formula for the standard deviation of the shear modulus, the following variables can be used:

strain
shear strain in percent
modulus
normalized shear modulus
Likewise, the following variables are available in the definition of the standard deviation of the damping:
strain
shear strain in percent
damping
damping in decimal
The following functions are available: