###### Abstract  
In the past several years, a series of artificial islands have been constructed on the top of coral reefs by China in the South China Sea by way of reclamation. A large number of revetment breakwater also has been built along the margin of these artificial islands. The stability of these revetment breakwater is the precondition for the normal service performance of these reclaimed coral sand islands. In this study, taking the reclamation engineering in the South China Sea as the background, a series of wave flume physical model tests (geometrical similarity scale is set to 1:10) are performed to investigate the dynamics and the stability of the revetment breakwater and its reclaimed coral sand foundation under the impact of regular wave. Experimental results show that the revetment breakwater has a maximum final settlement of 6 mm if built on loose coral sand foundation. Furthermore, there is indeed excess pore pressure generated in the reclaimed coral foundation with a maximum magnitude of 1.5 kPa. It is found that the excess pore pressure has not caused liquefaction in the coral sand foundation due to the fact that the accumulation of excess pore pressure only occurred in the first 10 cycles of wave loading. Finally, it is concluded that the revetment breakwater and its reclaimed coral sand foundation basically are stable under regular wave impacting. However, excessive water overtopping would be a potential threat for the vegetation behind the breakwater, as well as for the desalinated underground water of the reclaimed lands. stability of breakwater; reclaimed coral sand foundation; South China Sea; regular wave; revert breakwater; physical modeling +
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in the South China Sea will be impacted frequently by huge waves in their service period. Stability of these revetment breakwaters is the precondition for the safety of the artificial islands in the South China Sea. Therefore, it is of great engineering significance to study the stability of the revetment breakwater in the South China Sea under the long-term impact of the extreme waves. Many scholars have carried out a series of works on the stability of breakwater under the impact of ocean waves. Numerical analysis and physical model tests are mainly included. Remarkable progress has been made in the past 20 years on the aspect of numerical analysis. Many scholars have studied the stability of various types of breakwaters and the dynamic response of their seabed foundation by adopting elastoplastic finite element model developed by themselves or the commercial companies [6; 7; 8; 9; 10; 11; 12; 13]. However, the deformable seabed foundation was often regarded as a permeable but rigid medium in these models. In order to overcome this shortcoming, [PERSON] et al. [14; 15] successfully developed an integrated numerical model FSSI-CAS 2D/3D, which can take fluid-structure-seabed interaction into consideration. This model has been successfully applied to study the dynamics of seabed foundation and the stability of breakwater in a practical project [16]. In addition to numerical methods, it is also of great significance to carry out physical model tests to study the stability of large-scale breakwater in important projects in which complex conditions are frequently involved. A series of wave flume tests were carried out by many scholars to study the effect of different waveforms, in which regular and irregular waves were mainly involved [17; 18; 19]. These works have proved that regular waves would cause greater damage to breakwaters than random waves. It is noteworthy that [PERSON] [20] pointed out that the effect of the two kinds of waveform on breakwaters is basically the same if the wave height of regular waves is equal to the average value of the maximum 20 wave heights of irregular waves in a certain period of time. The conversion relations of wave impact on breakwaters induced by random waves and regular waves has also been deduced [21].