Experimental Investigations of Dynamic Wave Force on Seabed around a Geotextile Mattress with Floating Curtain

Xie, L.; Zhu, Y.; Huang, W., and Liu, C., 2015. Experimental investigations of dynamic wave force on seabed around a geotextile mattress with floating curtain.

A new technique called geotextile mattress with floating curtain (GMFC) may be an advisable alternative countermeasure against seabed erosion, since it can allow deposited sediment dunes to form naturally at upstream and downstream sides of GMFC when installed in erosive flow. However, cyclic loading of wave actions can lead to liquefaction of the seabed under the mattress, reducing the maximum friction resistance of the mattress, even leading to instability of the GMFC structure. Thus, in this study a series of physical model tests in a rectangular flume were carried out to investigate the behavior of a single GMFC and the hydrodynamic environment around GMFC subjected to wave loading. The wave force on seabed was recorded by pressure gauges installed on the flume bed. Experimental results indicated that some area of the unmovable bed around GMFC suffered much higher hydrodynamic pressure under the wave action. The areas directly facing the bottom openings of GMFC are more prone to bear higher cyclic force of wave actions. Moreover, the results also illustrated that the highest cyclic force of wave actions on the seabed appears at a distance of the mattress-curtain height to the GMFC centerline. The parametric study indicated that the opening ratio has a significant impact on the wave force properties.