Uplift pressures inside foundation (multiple-wedge analysis)
If failure planes are defined inside the foundation (multiple-wedge analysis), the "properties" button highlighted in yellow in the figure below allows access to the distributions of the uplift pressures inside the foundation.
The pressure distribution is divided according to each of the failure planes (wedges). The user must choose the active wedge using the drop-down list in the upper right corner of the dialog box. In the figure below, the first wedge is selected. The pressure distribution is expressed in terms of water height (piezometric height) along the wedge line from U/S toward D/S. In the figure below, the first wedge distribution is composed of two values:
- L = 0.000m; H = 17.270 m
- L = 9.434m; H = 16.224 m
The first value correspond to the most upstream point (L = 0.000m) having a piezometric height of 17.270 m. The second value (L = 9.434m) corresponds to the distance along the wedge from to the first point. In this case, since the first wedge has only two points for the distribution, the second point will correspond to the total length of this wedge.
Let's select the second wedge (Wedge #2) as shown in the figure below. In this case, the distribution is composed of three values. The intermediate value (L = 3.500m) correspond to drainage holes crossing the wedge profile. By default, CADAM3D calculates automatically the distribution according to USACE guideline (1995). However, the user may
The user may define his own distribution by clicking on the radio button "user defined distribution". At this point, the user can add a piezometric height by indicating a value of L between L = 0.000m and L = 10.000m for the example of wedge # 2 below as well as the corresponding water height and then click the Add button. Another option is to modify existing heights. To do so, the user must select a value from the list and then change its height value (H=) by clicking the Update button. Finaly, the user may delete a selection as long as it is not the first or the last one in the list.