A preparation technique for very homogenous sand models and CPT research

摘要

Delft Geotechnics has developed a technique for the preparation of very homogeneous sand models, based on the dynamic fluidisation-compaction method. By means of this technique very homogeneous sand models have been prepared with a relativedensity of between 30% and 70%, which are highly reproducible. The homogeneity of the density has been determined with a specially designed density measurement device. The measured local inhomogeneities are of the order of the accuracy of the soil sampler (0.9% of the porosity). The method has also been applied for a three sand layer system, with a tunnel face module implemented in the sand model. This has given very good and reproducible results.The homogeneous sand models have been used for CPT research. The CPT research consisted of the performance of CPT's at different g-levels, with different penetration velocities and different soil densities. Also, the diameter of the CPT's and the distance to the container wall were varied. The results have been compared with CPT correlations.