Creating an Irregular Surface Load

Select a load case either in the Load Description tree or using the Load Case Selector list in the Standard toolbar.
In the Main Navigator, in the Loads & Factors > Add Load for Mat Foundation group, select Add Irregular Surface Load. The Irregular Surface Details open in the Load Description pane.
Type the Number of Points to use as vertices for the irregular shape.
Note: This must be an integer greater than two to define a polygon.
Specify the pressure:
1. Select the Unit value to use for the pressure from the drop-down list.
2. Type a Pressure value.
Specify the location of each vertex:
1. Select the length Unit from the drop-down list.
2. Type an X and Y coordinate value.
3. Repeat step 3b for each vertex point.
Type an elevation value, Y.
Click Add. The load is added to the current load case in the Load Description Tree and is drawn graphically in the View wwindow.