Water Surfaces Overview
Water Surfaces are used for the following purposes in RocSlope:
- Pore Pressure - if the Groundwater Method = Water Surfaces then you can assign a Water Surface (e.g., Water Table, Piezo Surface) to calculate the Pore Pressure for a Material. Pore Pressure is proportional to the vertical distance from the Water Surface. For joints assigned with a Joint Property using Material Dependent Water Pressure Method, any portion of the joint which passes through the material will take on the pore pressure effects of the material.
- Joint Pressure - if the Water Pressure Method = Water Surfaces then you can assign a Water Surface (e.g., Water Table, Piezo Surface) to calculate the Water Pressure inside the Joints. Pressure is proportional to the vertical distance from the Water Surface. The selected Water Surface is used to compute the water pressure over the entire joint.
- Ponded Water - if a Water Table is defined above the slope surface, then Ponded Water is automatically created. The weight of Ponded Water is accounted for in the stability analysis, acting on the Free Surface of the block.
Water Surfaces are created and assigned as summarized below.
Adding Water Surfaces
Water Surfaces are created with the Add Water Surface or Add Water by Location options, and may represent a Water Table or a Piezo Surface.
Assigning Water Surfaces
In order for a Water Surface to be used in the RocSlope analysis, it must be either assigned to a Material or to a Joint Property.
Assigning Water Surfaces to Materials
Water Surfaces are assigned to Materials under the Water Parameters tab of the Define Materials dialog or with the Hydraulic Assignments Dialog. See the Assign Water to Materials topic for more details. In order for Material pore pressures to be used in Joint Water Pressure calculations:
- The Water Pressure Method must be set to Material Dependent for the Joint Property
- The Joint with the Joint Property must pass through the Material with the assigned Water Surface
Assigning Water Surfaces to Joint Properties
Water Surfaces are assigned to Joint Properties under the Water Parameters tab of the Define Joint Properties dialog. See the Define Joint Properties topic for more details.
Types of Water Surfaces
There are two different types of Water Surface:
The Water Surface Type is selected when you create a Water Surface with the Add Water Surface or Add Water by Location options.
Ponded Water
If a Water Table is defined ABOVE the slope surface, then Ponded Water is automatically created between the Water Table and the ground surface. The weight of Ponded Water is accounted for in the stability analysis, acting on the Free Faces of the blocks. See the Ponded Water topic for more information.