波浪作用下加固软基上大圆筒结构稳定性分析

在大型通用有限元软件ABAQUS平台上，通过二次开发，将软黏土的循环强度与D-P屈服准则相结合，基于拟静力分析建立了波浪循环作用下考虑软土地基弱化效应的大圆筒结构稳定性计算模型。结合某工程，对大圆筒结构的稳定性进行了分析。结果表明，考虑地基循环弱化效应时，大圆筒结构的稳定性安全系数显著降低；打设排水板对地基加固后，结构稳定性安全系数显著提高；在同一圆筒入土深度下，随着地基加固深度的增加，大圆筒结构稳定性安全系数明显增大。考虑地基循环弱化效应时大圆筒结构稳定性安全系数减小程度在30 %左右，建议在实际设计中应考虑软土地基循环弱化效应对大圆筒结构稳定性的影响。同时在地基不满足承载要求时，打设排水板加固软土地基是提高大圆筒结构稳定性的有效途径。

Stability analysis of large cylindrical structure for strengthening soft foundation under wave load

A quasi static finite element method for stability analysis of the large cylindrical structure considering the cyclic weakening effect of soft foundation under wave load was developed by combining the concept of cyclic shear strength with D-P yield criterion. Then the proposed method was numerically implemented in the framework of the general-purpose FEM software ABAQUS. According to a project, the stability of the large cylindrical structure was analyzed. The results show that the stability safety factor of the large cylindrical structure decreased obviously when strength weakening of soft ground was considered while increased remarkably when the soft clay was reinforced by driving drainage plate. And the stability safety factor of the large cylindrical structure increased obviously with the increment of reinforced depth for the same embedded depth of the large cylinder. Weakening degree of the stability safety factor of the large cylindrical structure is 30% when strength weakening of soft ground is considered; so it is suggested that the strength weakening of soft ground should be considered in practical design. Besides, reinforcement of soft soil by driving drainage plate is an effective way to increase the stability safety factor of the large cylindrical structure when the soft ground can't satisfy the bearing requirement of the structure.