河岸侵蝕對附近居民來說，是對他們的生命財產造成嚴重影響的自然災害之一。這種現象是河岸材料在被軟化及沖刷下而導致，其中影響因素有水流、船造浪、農業活動和河岸基礎設施等。由於土壤和水的界面十分複雜，因此土壤力學與流體力學間相互作用的研究十分少見。本研究目標為評估河岸在波浪作用下的力學行為模式。透過離心機模型試驗模擬，以評估波浪的動態壓力和侵蝕率之間的關係。在20g 人造加速度的離心機模型試驗結果中，模擬出了原型高度0.22-0.24 公尺的波浪。在靜水位高度，量測到的最大衝擊壓力約為28 kPa。試驗結果也表示波浪的頻率變化對衝擊壓力的影響並不大。 此外，侵蝕過程分為三個階段：侵蝕階段、張力裂縫階段和破壞階段。根據研究結果顯示，侵蝕率與波浪的衝擊壓力和土壤強度有關。當河岸材料的黏土占比增加時，侵蝕率會下降，在河岸材料侵蝕率為0.078 公尺/小時的條件下，“黏土區”的臨界侵蝕距離為2 -2.4 公尺。;Riverbank erosion is one of the natural disasters causing significant negative influences on the economy and life of people living near riverbanks. This phenomenon is triggered by softening and washing materials of the riverbank under factors such as water current, ship - waves, agricultural activities, and infrastructures on the riverbank. The interface of soil and water is so complicated that there is rarely research to study the interaction of hydrodynamics and soil mechanics. This study aims to evaluate the mechanical behavior of the riverbank under the effect of water waves. Several centrifuge simulations were performed to estimate the relation between the wave dynamic pressure and the erosion rate. The results indicated that the river waves could be generated with 0.22 m - 0.24 m in prototype under the artificial acceleration of 20 g. The maximum impact pressure is around 28 kPa at the still water level. The frequencies of waves are not essential to affect the impact pressure. Additionally, the erosion process is divided into three stages: erosion stage, tension crack stage, and failure stage. Based on the results, the erosion rate is dependent on the impact pressure of waves and soil strength. The erosion rate is decreased when the percentage of clay is increased, with the critical erosion distance of the “clay zone” of 2 m - 2.4 m and the erosion rate of 0.078 m/h.
