Zhang, Sijing (Wuhan University of Technology) | Wang, Lizheng (Wuhan University of Technology) | Xiong, Aokui (Wuhan University of Technology) | Chen, Shunhuai (Wuhan University of Technology) | Jin, Yan (Wuhan University of Technology)
At present, there are many problems in the middle reaches of the Yangtze river, such as the river channel twists and turns, and the instability of the river, which severely limits the large scale of vessels in inland river and the development of long-distance waterway transportation. A canal is currently being planned to address the problem, and two other issues have to be taken into consideration besides the basic construction cost of the canal. For one thing, restricted waters impose significant effects on ship navigation, so the limit of canal scale is important. For another, the ship wave has a wash effect on the riverbank and breakwaters, which increases the cost of bank embankments and breakwaters (a part of additional construction cost of the canal). In order to help find the optimal scale of the canal, which balances the ship's navigation performance and the construction cost of the canal, a study of the ship's resistance and ship wave propagation in different scale canals is carried on
In this paper, numerical simulation of a river-to-sea ship is conducted based on RANS equations in deep water at first, both in fixed condition and free condition (i.e. the trim and sinkage are allowed). And the validity of the numerical method is verified by comparing the calculation results with the experimental data. Subsequently, for varying water depth, water width and ship's speed, the ship resistance, the wave height at the bank are predicted by the verified numerical methods and the results are analyzed.
The region along the Yangtze river plays an important role in the development of China's economy, for it makes the western undeveloped region and the eastern developed regions connected together. In order to facilitate the development of Yangtze river economic Zone, it is necessary to build large-scale Vessel with greater load tonnage. In this environment, the navigation structure also needs to be improved to meet the needs of the ship's development. In fact, the current channel condition of the Yangtze river is the important factor that restricts the navigation capacity and sets limits on the economic development along the river. For example, there are twists and turns in the middle reaches of the Yangtze river, as shown in Fig. 1.
A new model is established to estimate the reaction forces and torques on cutter head of cutter suction dredger in rock dredging. In our model, the cutting parameters of the teeth on cutter head are determined by numerically simulating the relative positions between the teeth and rocks, then those parameters are used for calculating the forces on the teeth. Summing up all the forces on all the teeth and the moments of all the teeth around the axis of the cutter head, the reaction forces and torques on cutter head can be obtained. The proposed model is effective for estimating dredging loads.
Cutter suction dredger is a highly efficient and core piece of dredging equipment, which is widely used in the waterway dredging, port construction, and reclamation and other projects. The loads on the cutter head have great effects on the design of bridge structure and mooring of the ship, because the loads are transferred to the ship body through the bridge and are resisted by the loads on the mooring system. It is essential for the accurate calculation of the dredging loads that are imparted onto the bridge structure while dredging for safety. Pan (Pan, Yang and Tang, 2009) and Yang (Yang, Zhu, Fan and Pei, 2012) analyzed the dynamic loads on the cutter head in dredging sediment based on two-dimensional cutting theory. Li (Li, Jiao, Huang, Jia, Wei, Liu, Ai and Lu, 2013) simulated the sediment dredging process of the cutter suction dredger. With the development of dredging industry, the cutter suction dredgers are now used for dredging soft rock or hard rock rather than just for sediment or soil. Gao (Gao, 2007) introduced the technicals related to the rock dredging with cutter suction dredger. Yao (Yao, 2011, Yao and Yang, 2011) and Chen(Chen, 2012, Chen and Yang, 2013) investigated the methods to estimate the dredging loads of the large cutter suction dredger with the theory from coal mining. Ma (Ma, 2015, Ma, Ouyang, Yang and Liu, 2014) built a model to estimate the dynamic loads on cutter heads. In Ma’s model, the two-dimensional rock cutting theory was used to calculate the cutting forces, and the effects of some dredging parameters were investigated. However, in all of the models for estimating the dredging loads, the effects of the breakout angle on the cutting forces for rock cutting have not been considered except two-dimensionally, which can result in underestimating the fluctuation of the dredging loads.
In this paper, Combined with the Meizhou coal terminal, wave physical model tests are used to study of navigation channel on the impact of wave propagation. The results of physical model tests indicate that the navigation channel has a great effect on wave propagation: the change of wave height can be up to about 68 percent in heading wave of channel, especially, when the angle of incident wave is smaller, the change is bigger. With the angle of incident wave increased, the location of maximum wave height is closer to the navigation channel. The wave height will be bigger in the harbor on the condition of low water level because the navigation channel reduce the rate of wave broken. The results provide some reference to the planning and design of port and navigation works.
Zuo, Shuhua (Key Laboratory of Engineering Sediment of Ministry of Communications, Tianjin Research Institute of Water Transport Engineering, State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology) | Wang, Yingqi (Key Laboratory of Engineering Sediment of Ministry of Communications, Tianjin Research Institute of Water Transport Engineering) | Zhang, Ningchuan (State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology)
Pan, Lihong (East China Normal University, Shanghai Hydraulic Engineering Design & Research Institute) | Zhu, Jianrong (East China Normal University) | Wu, hui (East China Normal University) | Du, Xiaotao (Shanghai Hydraulic Engineering Design & Research Institute)
Li, Bei (Tianjin Research Institute for Water Transport Engineering) | Zhang, Zheng (Tianjin Research Institute for Water Transport Engineering) | Zuo, Shuhua (Tianjin Research Institute for Water Transport Engineering. State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology) | Zhang, Yun (Port Engineering Department, Tianjin University)
Based on the characteristic of the currents and sediments in the research area, a 2D numerical model for the current field by waves is established in the paper. The unstructured grids are applied to fit the boundaries of the Yangshan sea area and the regulation project, thus the calculation accuracy is improved. Verifications with the observed data indicate that the simulated results can reflect the current fields in the region. Based on the numerical model it is rechecked and reasearched the influence of branch blocking in different stages of northern port construction on the changing processes of hydrodynamic, including tide process, velocity and tidal prism, in the main channel waters and the branches. The paper is to provide the scientific basis for the construction of Yangshan Port’s subsequent engineering.
The Yangshan Deepwater Harbor lies in the Qiqu archipelago, which is located about 32 km northwest to Luchaogang Harbor in the Nanhui District, in northern Hangzhou Bay, and on the south side of the Yangtze Estuary, 86 km from the center of Shanghai（Fig. 1）. The Yangshan Deepwater Harbor is the first offshore deepwater harbor in China. The sea area is composed of southern and northern island chains. The southern island chain is from east to west starting from Dayangshan Island and the northern island chain is from northwest to southeast starting from Dawugui Island. The water depth of the main channel to Yangshan Harbor from Dayangshan Island to Dawugui Island is more than 10 m and Yangshan Harbor is the nearest deepwater harbor with natural advantages for Shanghai(ZUO et al., 2009a, 2009b, 2009c). The Yangshan sea area belongs to strong current flow and high suspended sediment concentration. The seabed evolution is aroused by suspended sediment transport