沉入式大圆筒结构入土深度计算方法研究

Calculation method for embedded depth of embedded large cylinder

沉入式大圆筒结构是一种适用于软土地基的新型港口与海岸水工建筑物。本文在由水平力和力矩平衡条件建立的入土深度计算方法的基础上,进一步考虑竖向力平衡条件,建立了沉入式大圆筒结构满足稳定性要求的新的入土深度计算方法。针对一工程实例的设计条件,研究了土性指标取值、波浪力大小和竖向力平衡条件对沉入式大圆筒结构稳定性(入土深度)的影响。结果表明,土性指标和波浪力对大圆筒结构的稳定性均有显著影响,且土性指标的影响大于波浪力的影响;当竖向力较大时,竖向力平衡条件对大圆筒结构的稳定性也有较大影响。建议在实际工程设计中,应准确选取土性指标,并采用考虑竖向力平衡条件的稳定性计算方法。

One the basis of analysis on acting forces and the condition of equilibrium a new method for calculating the embedded depth of large cylinder built on soft foundation is developed. In the method not only the horizontal forces but also the vertical forces, including the friction forces acting on the inner and outer surfaces of the cylinder and the reacting force of soil at the bottom of the cylinder, are being considered in the analysis of equilibrium.The method is applied to investigate the influences of soil behaviors, wave forces and vertical forces on stability of cylinder as well as the embedded depth. It is found that though the behaviors of soil and wave acting force are the main factors affecting the stability of cylinder but in some cases the vertical forces must not be neglected, since they may also affect the stability condition of the cylinder.