The Model Of Undrained Shear Strength Of Saturated Clay After Cyclic Loading And Its Application

Embedded large cylinder structures often embed in sand or clay soil, these kinds of structures which under the force of wind, current, ice especially random wave keep their stability by deeply embedded in the seabed. Structure-seabed coupling system under wave action is one typical embedded structure, because of its complicated dynamic interaction, there isn't being definitude analytic method can follow now. Study on dynamic responses of this structure has important value at engineering application and academic research.Wave load is the most frequent and severe of all the loads on the offshore foundation. As there's being contact interface and dynamic interaction between soil and structure, contact analysis becomes more complicate. It is generally held that offshore clay foundation is under undrained condition after a few hours to several days wave load. Increased strain, accumulated pore pressure, degraded undrained shear strength accompany changed internal structure is produced by sustaining wave action and upper building may unstable failure.In this paper, a dynamic finite computational model of the structure-wave-seabed coupling system is established based on MSC.Marc. The undrained shear strength after cyclic loading model and pore pressure model which are fit for saturated clay have been introduced into the coupling system by user's program interface in MSC.Marc. A new way to do dynamic analysis has been established. The numerical results are approximated to experiment observed data because of the advantaged model and reveal failure mechanism of the coupling system to some extent. Results of this paper lay a good foundation for the instability study of this kind of structure.