Zum Einfluss der Teilsättigung auf den Plattendruckversuch

On the influence of partial saturation on the plate load test.

Different soil tests for compaction control are used in earthworks in order to assess the compaction degree and the loading stiffness of the subsoil or the prepared planum. An example is the static plate load test, which allows to derive quickly and easily the subsoil stiffness from punctual measurements. The obtained stiffness modules for first loading and reloading of the subsoil are used for the design of pavements of roads and air fields. A large influence, widely disregarded in practice and also by design codes, appears with unsaturated soils, which represent the regular case in the field. Due to capillary effects the results of the plate load test can be strongly influenced, which may lead to misinterpretation of the stiffness modules Ev1 and Ev2. In this contribution the impact of degree of saturation and soil suction on compaction control with the plate load test will be discussed. For this purpose, results of model plate load tests on an unsaturated sand at a model scale will be presented.