GGU-CONSOLIDATE: Test 3 - Consolidation (numerical) with real pore water pressure distribution

The assumption that the pore water pressure at time t = 0 is constant across the whole layer depth is not exactly true. Because of the infinite extent of the embankment in section, lower pressures result. In order to consider the real pore water pressure distribution, select the menu item "Edit/Pore water pressure (max)" and then the "Generate" button. Enter the values into the dialog box.

The foundation width of 12.50 m is approximately the crown width of the embankment and half of each slope width.

For "Distance foundation base - layer top [m]", the top of the uppermost consolidation layer should always be taken as reference. This is not necessarily ground level, but must be taken from the system to be investigated.

In this example, the top of the uppermost consolidation layer is 2.0 m below the embankment; you must therefore enter a value of 2.0 for "Distance foundation base - layer top [m]". After confirming with "OK" the program models the stress distribution across the consolidation layers in accordance with elastic-isotropic half-space theory.

Using the "Forward" button, navigate through the list to view the stresses at a depth of 10.5 m. As an alternative to the automatic generation of pore water pressures you can, of course, also enter the values manually.

Select the "System/Analyse" menu item. Evaluation of the analysis shows that the consolidation time for 80% settlement has now been reduced to approx. 330 days, which is, of course, still not satisfactory for the impatient client.

In the initial task formulation it was noted that the embankment tipping time was around 100 days. The influence of this will now be investigated.