Horizontal And Vertical Pore Pressure Gradients Under Double Dam Break Driven Swash Event
Date
2022-05
Authors
Journal Title
Journal ISSN
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Publisher
University of Delaware
Abstract
The impact that pore pressure gradients acting within the sediment bed have on
sediment transport within the swash zone is not entirely understood, partially due to
the difficulty associated with taking in situ measurements within this portion of the
beach. The goal of this experiment is to observe horizontal and vertical pressure
gradients under a variety of hydrodynamic conditions to further this understanding.
The following experiment makes use of new pressure sensor arrays and finite
differencing to approximate horizontal and vertical pore pressure gradients at two
cross-shore locations of a wave flume outfitted with a double dam-break mechanism.
These gradients were calculated and analyzed for three different types of swash-swash
interactions.
Large destabilizing gradients were observed atop the bed and slightly below
the sediment-water interface for a variety of cases. These gradients were less likely to
destabilize deeper sediments farther onshore. Additionally, it is likely that plug flows
were formed at the onset of waves and possibly during successive wave-wave
interactions.
Further development of the pressure sensor arrays used in this study would
enable more extensive and robust datasets. Additionally, with more robust sensors, a
similar experiment may be conducted in the field.
Description
Keywords
Sediment, Pressure gradients, Pore pressure