海啸波作用下泥沙运动——Ⅳ.建筑物局部冲刷

基于波浪水槽实验，以沿海公路为对象，对海啸波作用下建筑物局部冲刷机理开展研究。实验采用1/10与1/20的组合坡度，选取N波作为入射波。实验对波高、波浪的上爬、回落和水跃过程、每个波作用后的地形进行了测量和记录。实验结果表明，N波作用下地形发生冲淤变化，在回落水流所形成的螺旋流作用下，路基向海侧形成明显的冲刷坑。路基所在位置是最主要因素，波高是次要因素，路基深度影响较小。路基位于滩肩侵蚀发生处，则最大冲刷深度相对较大。

Study of sediment transport by tsunami waves：Ⅳ：Local scour around structures

Tsunami scour around a coastal structure is one of the primary causes of structure damages. However, the mechanisms of tsunami-induced scour and beach erosion are less understood compared to that of tsunami run-up and tsunami inundation. A series of two-dimensional laboratory experiments of tsunami scour is conducted in accordance with coastal road conditions situated on a sandy beach. The initial 1/10—1/20 composite beach slope is respectively exposed to the N-waves. Measurements are made for the free surface elevations, the wave uprush and backwash processes, run-down jump, and the change of cross-shore beach profiles. The experimental result shows that there exists not only a profile change in the beach due to the impact of back sheet flows, but also the scour around the coastal road resulting from the helical flow. The location of roadway is a key factor affecting the scour depth along the coastal road. The incident wave height is also a contributing factor, but the depth of road embedment has little effect on the scour depth as shown in the experiments. The experiments reveal that coastal roads are vulnerable to tsunami damages due to serious scouring. The information reported in this study is useful for local authorities to better plan for tsunami disaster relief.