Large-diameter Cylinder Traits Of Anti-dumping

With the persisting development of water carriage project and the requirement of ships' enlargement, the large diameter cylinder structure is becoming a widely used structure in harbor, sea-route and offing engineering because of its advantages, such as its convenience in construction, lower expense, excellence of wearing and adapting to dicky environment. However, the interaction between the large diameter cylinder structure and the soil is so complex, especially its capability in resisting capsizal is still ambiguity, that in practical engineering, the designers have to make decision by their own experience or the experiment data collected from small size models..So this dissertation is aimed to discuss the capability in resisting capsizal of the large diameter cylinder structure by simulating the interaction between the large diameter cylinder and the soil through numerical value method.This dissertation took the usage of limited element method to simulate the large diameter cylinder, the soil and their interaction, which is based on the results of the research about capsizal experiment and theoretics analysis related to the large diameter cylinder. In the simulation, the load caused capsizal is located at the top of the cylinder. The nonlinear stress-strain behaviors of internal stuffing and the bedding was modeled via Drucker-Prager type. By transforming gravity field into initial stress state on each element, the initial gravity field was carried out. The dissertation considered the limit of capsizal as the moment that the press at the hallux becomes zero and analyzed the pressure at the bottom of the internal stuffing by using the ABAQUS software, then, calculated the efficient-rate in resisting capsizal and compared the results calculated by capsizal experiments and experience expressions to illuminate the effect of limited element simulation method.Through the numerical analysis, rules concerning internal stuffing in resisting capsizal can be obtained relation to the friction angel of internal stuffing, diameter of the cylinder, height of the cylinder, intensity of the bedding soil and the depth of the cylinder inserted. That the effect in resisting capsizal is more prominent while the value of internal stuffing's friction angel is larger, and the increasing rate will reduce in the process. The internal stuffing can't resist capsizal only through the friction between the wall of the cylinder and itself, but also through the slippage at a certain level in itself. And the effect will enlarge when the diameter of the cylinder becomes larger. However, change of the height of the cylinder has little effect on resisting capsizal. Of course, the better the mechanical feature of bedding soil is, more capability to resist capsizal it will provide to the internal stuffing. But there is only a little effect on resisting capsizal of the internal stuffing when the structure is in the form of flat buried.In addition, through the numerical analysis about the effect of resisting capsizal of the burying structure, rules concerning the structuer's resisting capsizal can be obtained relation to the friction angel of internal stuffing, diameter of the cylinder, height of the cylinder, intensity of the bedding soil and the depth of the cylinder inserted. Which is: When increasing the internal friction angle of the internal stuffing to a appropriate value can improve the resisting capsizal of capability of the whole structure. The capability of resisting capsizal can be improved by enlarging the diameter of the cylinder while exacerbated by increasing the height of the cylinder. And the capability of resisting capsize will be enhanced when the mechanical feature of bedding soil is better. Additionally, increasing the burying depth of the structure can improve the capability of resisting capsizal effectively.