Bathymetric Surveying Of The Maintaining Dredging For The Port On Muddy Coast

As the deepwater berth scale being larger and water channel deeper, the maintaining dredging will become one of the major tasks for the port authority. Particularly for port on muddy coast, the maintaining dredging is a long-term and complex work. The bathymetric surveying directly affects the result of the excavation volume. Present bathymetric survey technologies are mainly used to guarantee the safety of navigation. However,under the premise of navigation safety, it is of great significance to determine the water depth of maintenance dredging reasonably and reduce the cost of the maintaining dredging by improving the bathymetric surveying technology for the maintaining dredging of port on the muddy coast.In this paper, the development history of the bathymetric surveying technology is firstly introduced and the characteristics of the fluid mud are discussed. Through the large quantity work of field surveying, data analysis, precision checking and etc., the following results in bathymetric surveying for the maintaining dredging are obtained.1. For the port on muddy coast, the boundary of the high frequency ultrasonic survey is the top interface of the fluid mud. The fluid mud volume, called"watered excavation quantity"is incorporated in the excavation volume. The fluid mud has no effects on the safety of navigation, but dredging the fluid mud needs a lot of human and material resource which will bring about a lot of waste.2. The bulk density value of the fluid mud interface for the maintaining dredging is determined in the paper.3. The method to survey the fluid mud interface for the maintaining dredging is developed. By data collecting and checking, the conclusion can be drawn that the bathymetric surveying for the maintaining dredging can meet the demand of the interface surveying for the dredging.The methods developed in this paper have been applied in the maintaining dredging of Tianjin Port. The result indicates that the application has produced large economic benefits for the port on muddy coast.