A recent development in the testing and designing of weirs is the use of probabilistic methods. In these kind of analyses the variation in soil properties plays an important role. The variation in soil properties is hard to determine because soil samples get slighlty disturbed during sampling. Because of this the variation in soil properties following from the laboratory research is larger than in reality. Through the sampling of large volumes of soil a small undisturbed sample can be trimmed under conditioned circumstances in the laboratory. Deltares has also developed a series of large laboratory devices to test fibrous peat. These tests also contribute to approaching the real soil behaviour. This last year a sampling device, the Deltares Large Diameter Sampler (DLDS), is developed to take samples with a large diameter. The development is supported by TKI Deltatechnologie.
The last months soil samples were succesfully taken untill a depth of 4.5 m at several locations. With the device samples with a diameter of 400 mm and a maximum height of 1000 mm can be taken.
Also samples were taken with the Sherbrooke sampler to test the quality of the DLDS samples.