Theoretical Analysis And Model Test Of Bearing Capacity Of Suction Caissons With Taut Wires In Soft Clay

As exploration and production of oil resource progresses into deep waters, suction caissons with taut wires may be an important offshore foundation. However, because the work mechanism of this offshore foundation is different from the traditional gravity foundation and pile foundation, it lacks sophisticated design code at present. So it is important work to evaluate the capacity of suction caissons with taut wires. In this article, the studies are emphasized on the method of theoretical analysis and model tests of suction caisson in clay.First, the analysis of bearing capacity of suction caissons with taut wires is based on the theories of the upper bound limit analyses and the limiting equilibrium. The formulas of deriving and parametric study are described in this paper. Based on the characteristic of the two methods, I have compiled programs to calculate capacity of suction caissons with taut wires.Second, model tests of bearing capacity of suction caissons in soft clay were conducted in order to detaile the methods of upper bound limit analyses and limiting equilibrium in calculating reasonably capacity of suction caissons with taut wires. In model test, two suction caissons with slenderness ratio of 4, 6 and the load inclination degrees of 20°, 30°and 40°were used to study the failure mechanism under different load inclination degrees and capacity with different slenderness ratio, different load inclination degrees. We can obtain the capacity of suction caisson is affected by the changes of slenderness ratio and load inclination degrees. We obtained the failure models of suction caisson are affected by the inclination degrees and capacities are changed with different slenderness ratio and load inclination degrees. The failure models of suction caisson are same, when the caissons are with the same inclination degree and different slenderness ratio. The model tests of results are also compared with those from upper bound limit analyses and limiting equilibrium. We obtain that the method of upper bound limit analyses and limiting equilibrium are reasonable on calculating the capacity of suction caisson.At last, I compared the method of upper bound limit analyses and the method of limiting equilibrium on failure model, failure mechanism, parametric study and course of calculating. The method of upper bound limit analyses can not express the failure model, but the method of limiting equilibrium can express the failure model. The method of upper bound limit analyses can calculate the capacity of suction caissons in the case of rotation at failure. However the method of limiting equilibrium can only calculate the capacity of suction caissons with loading at the optimal loading point (no rotation at failure)...