Piezo lines are generally used when there are multiple water tables for different materials or when there is an artesian condition for one of the materials.
The method of pore pressure calculation is exactly the same for a Water Table or a Piezometric Line. However, Piezometric Lines are differentiated from the Water Table in Slide for the following reasons:
- The Water Table can be used to define ponded water, by simply drawing the Water Table above the External Boundary. A Piezometric Line drawn above the External Boundary, will NOT define ponded water.
- A Water Table allows you to define different Unit Weights for a material above and below the Water Table. This cannot be done with a Piezometric Line.
- A Water Table can be used in conjunction with a Pore Pressure grid, to ensure that pore pressures above the Water Table are always zero. (See the Water Pressure Grid topic for details.) Piezometric Lines cannot be defined in conjunction with Water Pressure Grids in Slide.