本報告是海工學門海岸空間利用第六整合型計畫「海域地形變遷」之一三年期子計畫之總結報告,研究範圍是針對沙質海床在波浪作用下之孔隙水壓反應,將之歸納並進而提供實驗時海床表面之懸浮飄沙之觀察結果。主要執行方式是採二維造波水槽試驗配合理論驗證。試驗用土壤採用中值粒徑d50分別為0.085mm及0.125mm之沙土,其反應特性歸納為三類。研究分析指出沙質土壤之反應與沈泥有許多不同,特別是在液化反應機制與孔隙水壓之消散能力,但兩者在液化後土壤有明顯之懸浮漂沙發生則有一致之結果。 This report summarizes the three-year experimental studies on mechanism of wave-induced seabed instability for one of the subprojects of the Coordination Project entitled "Geomorphologic Changes in Marine Areas". It is found from 2-D wave flume tests on two sandy seabeds (d50=0.085mm and 0.125mm) that under wave loading the sand responses can be classified into three categories based on pore pressure built-ups. The characteristics of the fluidized responses in sands are much different from those in silts, especially no resonance mechanism is clearly identified in sands. However, significant sediment suspensions are similarly observed in fluidized tests as were on previous fluidized silt tests.
Suspended sediment density