Direct Simple Shear (DSS)-test
Since the beginning of 2009, the geotechnical laboratory of MOS Grondmechanica has specialized equipment for conducting Direct Simple Shear (DSS) tests. The 4 configurations which MOS Grondmechanica currently has are interesting for research on weak material and particualarly on peat in areas where the risk of shifting needs to be determined. They are mainly used to research the strength of dykes.
In this test, a sample (clay, peat) is consolidated. Through the use of a large number of rings around the sample, a KO consolidation occurs. After consolidation , the sample is shifted horizontally. This is called undrained, by maintaining the height at a constant level and by varying and registering the stress that is needed for this. The shifting takes place by shifting the bottom of the sample at a constant speed. This shifting occurs under plane strain conditions.
Direct Shear (DS)-test
The DS test is a similar test as the DSS test. The difference with the DSS test is that the shifting surface is horizontal with a constant load applied to the top.