ABSTRACT
The aim of the present research project was to find suitable approaches for the assessment and evaluation of bearing capacity measurements with the TSD.
In a first step, the state of the art regarding bearing capacity measurements with the TSD were established. A further area of research is the empirical data available of TSD deployment. This was used as a transition to the introduction of possible bearing capacity parameters. A total of 26 bearing capacity parameters were identified, which are used as characteristic values of the structural substance of pavements.
Additionally, the influence of environmental circumstances on the measurement was analysed. It can be stated that the measuring speed has hardly any influence within the usual speed window (v > 20 km/h). Wheel load has an influence, but the scattering can be compensated by a linear correction approach. The temperature has a decisive influence, the correction approaches presented can also limit the influence to some extent, but these must be refined for the TSD measurement procedure.
At the same time, the deformation bowl calculation methods were also analysed. The area-under-the-curve method (AUTC) and the PEDERSEN method (2013) were compared by using 3D-Move simulation. The result was that the AUTC method shows deviations due to the tailtaming approach for stiff pavements, whereas the PEDERSEN (2013) approach shows very good agreement throughout.
In 3D-Move, a large number of simulations were carried out in which a lot of parameters were varied. For this purpose, all corresponding bearing capacity parameters were calculated, resulting in a sensitivity analysis that allowed statements about their respective significance. This makes it clear that the parameters of the SCI family are very reliable parameters for describing the stiffness of the layer under consideration. The same applies to the characteristic values of the stiffness backcalculation method (SBM).
