CPTu data can be used to directly estimate induced settlements due to an external load. CpeT-IT uses the following simple formula (based on 1-D consolidation) to estimate vertical settlements:
where:
q: applied footing pressure
h: calculation layer thickness
Iz: stress reduction factor according to Boussinesq
MCPT: Constrained modulus of soil layer
After you have selected a CPTU file from the CPT file Manager click on then settlements calculation tool button 
. The following dialog will appear:
Settlements calculation dialog
All properties used for the calculation can be entered on the fields that appear at the top of the dialog. When all input data are entered the calculation is performed by clicking on the Calculate button. The Graphical results tab will display the calculation results using the three plots available. The Tabular results tab displays the numeric calculation results inside a table as shown in the picture below:
Numeric results of settlements calculation
Double clicking inside the table initiates the procedure to export the results in a XLS file format.
To preview the settlements report, click on the Report button.
Settlements report preview dialog
Creep settlements are estimated using the simplified approach suggested by Messi (1994) where:
where M is estimated from the CPT.
Note The plots left axis scales used are taken from the Cone resistance qt plot in the Basic plots tab of the main application window. |