Rocscience International Conference 2025 is going to take place in Sydney, Australia Read more

Search Results

Define Hydraulic (Phreatic Surfaces)

If the Groundwater Method = Phreatic Surfaces, then the Define Hydraulic Properties option allows you to assign Phreatic Surfaces to each material (or specify an Ru value).

  1. Select the Groundwater workflow tab Groundwater workflow tab
  2. Select Define Hydraulic Properties Hydraulic Properties Icon from the toolbar or the Groundwater menu. This will open the Material Properties dialog to the Hydraulics tab.
  3. TIP: the Hydraulics tab can also be accessed directly from the Material Properties dialog.

  4. Select the appropriate Material from the left of the dialog.
  5. If you have added any phreatic surfaces to the model you can assign them to the material using the dropdown menu as the Default Water Condition. You can also select Add Hydraulic Parameter Add Hydraulic Parameter Icon to use one of the below methods for calculating pore pressure. If you assigned a previously added phreatic surface, skip step 5 and 6.
  6. In the Add Hydraulic Parameter dialog, assign the Type and Value of the parameter as desired.
  7. Select OK. The hydraulic parameter is added to the Default Water Condition dropdown list for the currently selected material. You may also edit or delete the currently selected Default Water Conditions by selecting the Edit Hydraulic Parameter Edit Hydraulic Parameter Icon button or the Delete Hydraulic Parameter Delete Hydraulic Parameter Icon button, respectively.

Add Hydraulic Parameter


The Default Water Condition can be selected to be defined as a Pore Water Pressure (PWP). A constant PWP is applied to all the nodes for a geometry that has the assigned material.


The Default Water Condition can be selected to be defined as an Ru value.

An Ru value simply models the pore pressure as a fraction of the vertical earth pressure. The vertical earth pressure is estimated from the unit weight and height of each material directly above a given point. The Ru Value is normally between 0 and 1.

An Ru Value can be specified for a material if the Groundwater Method = Phreatic Surfaces in Project Settings.

If one soil type has regions of differing Ru values, then a different material will have to be defined for each different Ru value. Appropriate material boundaries will have to be added to the model, in order to define the different soil regions.

Stage Default Water Condition

If your model consists of multiple stages, and you require different default water conditions to be applied at different stages, for a given material, then within the Staging tab of the Material Properties dialog, use the Stage Hydraulic Properties option. This allows you to simulate, for example, the draw down of a water table at different stages.

To assign the staging of Default Water Condition:

  1. With the Default Water Condition entered in the Hydraulics tab of the Material Properties dialog, navigate to the Staging tab and select the Stage Hydraulic Properties checkbox.
  2. Now select the Add Stage button, until the number of rows is equal to the number of stages at which you need to specify a Default Water Condition. For example:
    • if you need to assign 3 Ru values at 3 different stages, then select Add Stage three times, so that a total of 3 rows appears in the data entry area below the Stage Hydraulic Properties checkbox.
  3. If the Add Stage button is disabled, this means that you have not set the Number of Stages in Project Settings. In this case, go to the Project Settings dialog, and define the number of stages.
  4. In each row, enter the Stage number at which the Default Water Conditions are to be assigned.
  5. In each row, select the Default Water Condition representing that you wish to assign at the specified stage.
  6. It is important to note that you only need to define the Stage and Default Water Condition information for the stages at which the Default Water Condition will change. You do not need to define this information at stages where the Default Water Condition does not change.
  7. If you accidentally add too many rows with the Add Stage button, click the mouse on the row number and select the Delete Stage button, to delete the row.
  8. When you are finished entering the Stage and Default Water Conditions, select OK to close the dialog.
  9. When the analysis is run, RS3 will use the Stage and Default Water Condition information in the Material Properties dialog, to determine the correct Default Water Condition to be used at each stage of the analysis, for each material.

Rocscience logo, click here to return to the homepage Portal Account Portal Account Log In Log Out Home Shopping Cart icon Click here to search our site Click here to close Learning Tech Support Documentation Info Chevron Delete Back to Top View More" Previous Next PDF File Calendar Location Language Fees Video Click here to visit Rocscience's LinkedIn page Click here to visit Rocscience's YouTube page Click here to visit Rocscience's X page Click here to visit Rocscience's Facebook page Click here to visit Rocscience's Instagram page Click here to visit Rocscience's Reddit page Bookmark Network Scroll down for more Checkmark Download Print Back to top Single User Multiple Users RSLog RocFall3 CPillar Dips EX3 RocFall RocPlane RocSlope3 RocSupport RocTopple RS2 RS3 RSData RSPile Settle3 Slide2 Slide3 SWedge UnWedge RocTunnel3 RocSlope2 BlastMetrix ShapeMetriX Fragmenter Commercial License Education License Trial License Shop safe & secure Money-back guarantee