Investigation of stress-strain relationships in soil is usually carried out with triaxial tests where undisturbed, remoulded or compacted specimens are subjected to different stress levels and drainage conditions to simulate as closely as possible the different situations that can occur in the subsoil on site and the possible effects of construction, excavations, embankments, landslides, etc.
How to prepare a clay undisturbed sample for triaxial testing
Place the clay block on the turntable. This apparatus is used to prepare any size of cylindrical soil sample. Grease the cutter that will be used to obtain the cylindric sample from the clay block and place the cutter with the sharp edge towards the sample. Place a plate between the compressing platen and the cutter and lower the compressing platen in order to hold the clay block. With a blade cut out the outer part of the sample. In order to remove further layers, keep moving the two rods of the apparatus towards the center. When this procedure is finished, cut out the sample cylinder. Use an extender of the cutter in order not to damage the sample cylinder with the plate. Extrude half the sample from the cutter cylinder using a specific tool and then continue manually to avoid damaging the sample. Place a wet porous disk on the base adapter and a wet paper disk over it and place the sample in the triaxial cell. The use of lateral filters will speed up saturation and consolidation processes. After closing the triaxial cell, lay gently the piston load on the top cap and adjust the axial displacement transducer. The sample is ready for testing.
Watch the video below that demonstrates the preparation of a clay undisturbed sample.
Visit CONTROLS Group site if you want to find more about the aforementioned apparatus, triaxial cell, and sample preparation accessories.