GGU-DRAWDOWN: "Analyse" menu item

With this menu item you can begin calculating the installation. First, a plausibility control of the input data will be carried out. If necessary, you will see an error message, with an appropriate note on corrections. A dialog box with analysis preferences then appears. It can also be opened by pressing the [F5] function key.

You can control the type of calculation of the wetted filter length. Further to this, you can select whether the drawdown, and with this the wetted filter length, is to be calculated with the surcharge α, for achievement of the equilibrium state. If the "= fixed value" setting has been specified as the range in the "Edit/Base data" menu item, a further input box appears in the dialog box above, allowing the value for the range to be defined:

Using a random generator the program searches for the least drawdown within the excavation. This is almost always at the well edge. But it also makes sense to search inside the excavation, especially with excavations bounded by a polygon and complicated well installations. With "No. of hits for minimum drawdown" you define the number of points to be searched for by the random generator, within the excavation.

After selecting the "OK" button, the calculation of the installation takes place. If adequate dimensioning cannot be calculated, error messages will appear, with notes on recalculation.

Otherwise, intermediate results will be shown on the screen, which will also appear in the result legend and in the protocol. After successful calculation, the drawdown in the wells and in the centre of the excavation or, for rectangular excavations, in the centroid, will be displayed graphically on the screen. Additionally, "MUP" designates the most unfavourable point.