Modeling And Numerical Simulation Analysis Of The Stability And Ballast Pressure Of Super-size Caisson

With the development of world economy and globalization, as the bridge linking the world, ports get a new development opportunity. Our country has constructed lots of large-scale ports to meet the continually increment of the imports and exports. The gravity caisson is widely used in the districts with well foundations. But the current Gravity wharf design standard is generated from the experiences of building small-middle-size ports in the past. While building the super-size caisson with huge size and weight, we do not have a successful engineering example to follow. Therefore, the study of the super-size caisson plays a critical role in the development of economy and the ports.In the first section of this paper, the previous researches of correlative study are concluded and summarized. And then the model tests of Fujian Meizhouwan super-size caisson bulk cargo port is carried thought in the laboratory. According to the model theory, the size of the caisson and the real load are modeled in a proper ratio. In the model tests, the loads are assembled in a way that happened when the port runs daily. The purpose of the model tests is to verify the stability of the super-size caisson under the action of the assembled loads during constructing and running periods of the port. According to the results of the tests, it is suggested that while constructing the port the breast wall should be placed before the backfilling. This sequence can effectively reduce the displacement of the caisson during the construction. Under the combined loads, the seaward displacement of the caisson is pretty small, the caisson structure is deemed to be steady. In the destructive tests, the seaward displacement of the caisson became larger under the increased loads. Therefore, overloading of the stacking yard should be prohibited when the port running.After the model tests, based on the large finite element software ABAQUS, three-dimensional numerical model of the super-size caisson is built in the numerical simulation analysis to verify its stability. The results show a good agreement between numerical simulation and the model tests. According to the deformation and stress concentration of the super-size caisson, some reasonable suggestions are put forward to guide the construction and daily running of the port. Besides the simulation of the stability of the super-size caisson, the three-dimensional numerical model of the silo is built to analyze the barn pressure. Then the results of numerical simulations have been compared to those that calculated according to the ballast pressure formula in the current Gravity wharf design standard. It shows that the difference between the two results is small. In the actual engineering, the filling materials of the silo may be different, not only single. The simulation results of this situation show that the ballast pressure formula in the current Gravity wharf design standard is not suitable for the calculation of the ballast pressure in the not-single filling materials situation.