Abstract:
Strong turbulent flow has a great influence on the bed form in the wave broken zone. Based on the wave flume experiments, studies of the bed form and forces acting on the sediment in the wave broken sections have been carried out. According to the analysis of the bed form, it is found that the form of the sand ripple, sandbar and wave in the same place is basically consistent; the wave height and wave period influence the size of the sand ripple and the sandbar; the higher the wave height, the higher the sand ripple and sandbar; the larger the wave period, the longer the sand ripple and sandbar, and vice versa. The near bottom velocity and pore water pressure have been measured along the wave broken sections. Comparing and analyzing the surface uplift force and excess pore water pressure, it is concluded that the values of uplift force and the bed excess pore water pressure amplitude are the same. At the same time, the bed elevation in the broken zone is observed and further studies are made of the relationship among surface uplift force, excess pore water pressure and bed elevation. The analysis results show that the surface uplift force has increased with the increase in the bed elevation and decreased with the decrease in the bed elevation. However, the relationship between the excess pore water pressure and the bed elevation is quite opposite.