STUDY ON SEDIMENT CARRYING CAPACITY OF BREAKING WAVE IN MUDDY COAST

The muddy coast is an important part of the sea coast of Chinas mainland. The muddy plain coast have smaller bank slope, the breaking wave strengthens turbulence of water near the bottom of sea bed during the stormy. Sediment incipience and suspension become easier. Thus high sediment concentration is formed. The determination of sediment carrying capacity is of great significance and value to sediment transport, sediment deposition and erosion. The study on sediment carrying capacity under wave action is not yet mature, and the calculation results of various formulas showed larger difference, while the sediment carrying capacity under the breaking wave action is relatively less studied. In this paper, Bagnold's energy balance principle is used to deduce the formula of sediment carrying capacity under breaking wave action. The coefficient of the formula is calibrated by the flume test data. The calculated values of sediment carrying capacity formula are compared with the field measured data during Weipha typhoon in Lianyungang sea area. The maximum value of the measured vertical line average sediment concentration is respectively 2.27kg/m(3) and 1.67kg/m(3) at point on the isobath of -3m and -5m. The calculated value of formula is 2.22kg/m(3) and 1.73kg/m(3), respectively. The calculated value of sediment carrying capacity formula is compared with other field and test data. The comparison results show that the calculated values can better reflect the measured sediment concentration. Under the breaking wave action, The sediment concentration is very complex in time and space distribution. The vertical distribution of sediment concentration has many form characteristics. Therefore, when the formula of sediment carrying capacity is calibrated, it is necessary to screen the measured sediment concentration. When the formula of sediment carrying capacity is applied, the characteristics of breaking wave and sediment in the sea area should be fully understudied.