Security Analysis Of Steel Sheet Pile Quay-wall Under Ship Collision

Since the reform and opening up, with the sustained and rapid development of China’s national economy, the rapid development of marine transportatio, the amount of foreign trade is increasing by year. The increased entering leaving the port frequency of ships leads to the frequent accidents of collision between ship and wharf. It has also leads to great financial losses and casualties, and the indirect loss is immeasurable. Also it brings security risk to the wharf. As a significant type of wharf, the sheet-pile quay-wall has a lot of advantages such as low cost, simple structure, convenient and quick construction, and greater adaptation to the complex geological conditions and so on. The steel sheet pile has advantage of light weight, great strength, tight lock, better water stop, easy pile sinking and it has been widely used in large deep-water wharf engineering. In engineering at present, qualitative theoretical analysis method is widely used in studying the collision between the ship and the wharf. Field measurement analysis method and model test analysis method are adopted in the more important project. However, the finite element method has just started. But because of the rough result of qualitative theoretical analysis, there may be a big difference between the result and the physical truth. Also both the field measurement analysis and model test analysis need plenty of manpower, material resources, financial resources and long time, and it can’t give the situation of the deformation and stress transfer within the structure in every moment. Therefore, this thesis uses finite element method for analysis of steel sheet pile quay-wall.Firstly, it shows the current situation of domestic and foreign of the collision research between ship and wharf, the calculative theory and method of ship impact force and the calculative method of sheet-pile wall. Then it expounds nonlinearity of the soil material, nonlinearity of the pile-soil contact and nonlinearity of collision process. And the thesis details the selection of unit types, the selection of material types, the definition and selection of contact pairs and so on.Then, it establish numerical mode by the finite element analysis software ANSYS, and conduct a finite element analysis on the steel sheet pile quay-wall under its own weight and cargo loading. Then it comes to some reference value result to the wharf design. It analyze the effect of placement of horizontal load, the thickness of steel sheet pile, elastic modulus of backfill and angle of horizontal load on steel sheet pile of wharf by numerical simulation and fit the colculation results to summarize some rules.Finally, it studies the security of wharf structure between ship and steel sheet pile quay-wall by LS-DYNA. It’s verifyed that security of wharf structure under the normative speed impact. It analyze the effect of DWT of ship, speed of ship, elastic modulus of backfill on impact force, equivalent stress of steel sheet pile, pressure of breast wall and energy of soil by numerical simulation. Then we compare the impact force bewteen FEM and empirical formula of domestic and foreign, and summarize some rules. It provides theoretical reference basis for the design, maintenance and reconstruction of similar wharf and research impact force for collision between ship and similar wharf.