Impact of ship waves on soil embankments - A new measurement system for quantifying stresses in water and saturated soils = Auswirkungen von Schiffswellen auf die Stabilität von Uferböden - Ein neues Messsystem zur Quantifizierung von Spannungen im Wasser und dem gesättigten Boden

Abstract

The renaturation of river and coastal embankments needs to include ecological aspects and the stability of shorelines. The impact of waves caused by heavy ship traffic could lead to erosion processes and to the degradation of soils along the coast. To evaluate the stability of shorelines it is necessary to quantify soil stability parameters as well as stress impacts of the waves. Therefore, stress measurements of ship waves were carried out at Kiel Canal. In order to determine the three main stresses (σ1, σ2, and σ3), the averaged mean stress (MNS), and the oc-tahedral shear stress a new developed stress state transducer system was firstly tested. This newly constructed system (Mudflat-SST) is equipped with an exchangeable battery for long time measurements and waterproof, which allows measurements in water and saturated soils. The sensors heads were placed above and below the middle water level for determining the effect of waves and a potential drag effect. During two periods, different types of ships were measured such as container vessel, cargo ship, ferry, and catamaran. Maximum stress impacts of 3 kPa were determined. The results show different kind of waves regarding their period or expression for the different ship types. In order to quantify the maximum stress impact of breaking waves, further research is needed to optimize sensor head´s location in the water and saturated soil.