Load bearing analysis of suction bucket structure and analysis of foundation envelope under different loading modes

It is an important way to evaluate the stability of foundation that should establish the envelope of bearing capacity of foundation under different loading modes by means of numerical analysis or test. According to the engineering geological conditions, we establish a three-dimensional large-scale numerical model of suction bucket-stratum by finite element method. The deformation and bearing capacity of bucket foundation under horizontal load, vertical load and bending moment are calculated. The results show that with the gradual increase of load, the displacement of composite bucket foundation increases linearly at the initial stage, increases exponentially at the later stage, and becomes unstable at last. Appropriate vertical load is beneficial to improve the horizontal and bending moment bearing capacity of composite bucket foundation, while excessive vertical load is unfavorable to the stability of foundation. The failure envelope of bucket foundation plays an important role in structural design, foundation stability judgment and overall safety evaluation. Under the action of limit horizontal load (or limit bending moment and limit vertical load), the limit rotation angles are close to 7‰. The safety margin of vertical load is the largest, which can increase by 500% and remain stable; The safety margin of bending moment is the smallest and can only increase by about 46%.