Soil Set [SIG]

Empirical relationships from the literature are utilized to generate nonlinear soil/rock springs when using beam-on-nonlinear Winkler foundation methodologies. Three parameters are crucial in creating these curves: pile dimensions, soil properties, and depth below the ground surface. Moreover, the soil resistance curves are generally derived in a force per unit length or force per unit area format. For instance, p-y curves are derived on the basis of force/length vs. displacement, and t-z curves are derived on the basis of force/area vs. displacement. At the depth below the ground surface where soil resistance is modeled, the geometry of the pile and the properties of the soil play a critical role in the production of soil curves. More specifically, for every unique pile geometry and for every node along the pile in the corresponding finite element model, a unique set of calculations must be carried out to generate nonlinear soil resistance curves that attach to said node.

OpenBrIM utilizes soil sets to generate nonlinear soil resistance curves on each Pile/Pile Layout. The Soil Set definition, when paired with the Pile/Pile Layout, ensures that the appropriate pile geometry and soil properties are matched. Therefore, for every Pile/Pile Layout, there must be a unique Soil Set definition.

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Fig. 1. How to define Soil Set

Soil Layers:

• Soil Layer: Enter the soil layer.

• Specify Top and Bottom Layers[Yes/No]: If the engineer wants to specify different soil properties at the top and bottom of a layer, this option should be set to Yes. Please note that the Top and Bottom layers must be defined separately using the Soil Layer tool.
  In OpenBrIM, the Top and Bottom layers must be specified with two separate layer objects. However, these objects must have the same soil material models and identical top and bottom elevation inputs. Details are shown in Fig. 2.
  Linear interpolation is performed for soil properties during the calculation of soil springs between the top and bottom layers.

• Top Layer: Enter the top soil layer.

• Bottom Layer: Enter the bottom soil layer.

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Fig. 2. How to Specify Top and Bottom Properties Separately for a Soil Layer

Water Table Elevation: This parameter specifies the global elevation of the water table. Suppose the vertical profile of the alignment is defined, value of the Water Table Elevation has to be entered accordingly.

Generate Report[Yes/No]: Users can choose whether to generate a Soil Set Report. If a Soil Set is assigned to any Pile/Pile Layout, the report will be generated automatically. It can be accessed via the DOCS button on the left sidebar.
The report includes general information about the Soil Set, Soil Layers, and p-y, t-z, q-z, and t-θ graphs and tables for all nodes.

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Fig. 3. Example p-y Graph from Soil Set Report

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Fig. 4. How to assign soil set to a pile/pile group

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Fig. 5. 3D Visual of Soil Set