Research On Sediment Erosion And Siltation Test In The Harbor Area Of Sanao Nuclear Power Plant

The SanAo nuclear power plant port is an important place for the provision of materials for the nuclear power plant construction and operation,which plays an important role in nuclear power plant operation.Since many ports in China have different levels of siltation,it is necessary to maintain adequate depths for ships access through remediation and dredging.On the basis of summarizing international related research achievement,simulating the erosion and siltation of the sea near the port of SanAo Nuclear Power Plant through physical model tests,and discussed the impact of wave,tide and engineering factors on erosion and siltation.The main research contents and conclusions are as follows:(1)The design method and production process of the sediment physics model test were introduced.After verification of the model's various tidal levels,water flow velocity and direction as well as sediment content at the measure points,verified the terrain erosion and siltation of the sea area near the nuclear power plant and the effect of the storm surge were performed on trial tunnel,the verification result meets the specification requires.(2)Analyzed the rising and falling flow fields in the waters near the site,the harbor basin under ordinary waves is micro scour and silt,but the storm surge caused a large scale of siltation in the harbor basin,the effect of wave-lifting-sand on sediment deposition in the sea area is particularly significant.(3)The sediment shape is related to the flow pattern in the harbor basin.The flow field in the harbor basin has a circulation under the influence of the breakwater and the drainage channel,the flow velocity in the central part of the circulation is relatively slow and gradually accelerates toward the periphery,the sediment deposition intensity in the center of the basin is the highest and gradually decreases toward the surroundings.(4)The average siltation intensity in the basin under ordinary waves is 0.26 m/a,and the annual sediment yield is about 403,000 m~3.The sediment deposition of the basin during the week's storm surge is about 236,000 m~3,compared with the pre-project,it has reduced 355,000 m~3,the siltation reduction rate is 60%,after reduce the length of the breakwater,the siltation reduction rate in the corresponding harbor reaches 79%,which proved that this kind of harbor basin with drainage channel can provide a dynamic effect.When the breakwater is short,the dilution effect of the drainage against the entrance sediment is stronger,and it has better effect on sand control and silt reduction in the basin.