Evaluation of Submarine Strain-Gage Systems for Monitoring Coastal Sediment Migration

摘要

Single and multiple strain-gage systems were respectively evaluated as in situ point and areal sensors for monitoring sand-height variations in coastal environments. Static loading tests indicate that gage response pressure is linear for sand heights up to 24 inches. Response pressures are a function of both sand height and aggregate density, with density being influenced by both sediment texture and degree of compaction. Poorer sediment sorting and greater compaction result in higher response pressures. Dynamic loading tests conducted in a re-circulating flume indicate that gage response is not significantly influenced by either hydraulic flow velocity, or the migration rates of varying-textured bed forms. Response dispersion levels under dynamic conditions are formidably high, as a result of packing and density inconsistencies induced by transport processes. This results in sufficiently low reproducibility to critically limit the systems' potential as quantitative research instruments.