An Analysis Of The Motion And Strength Of Jack-up During Emplacement

This paper presents analysis method of Jack up's motion and strength during emplacement. It studies the dynamic responses of Jack up during its'emplacement to confirm the force of collision to security verification and that has a great important guiding significance in emplacement of jack-up.This paper reviews the development process and the status of jack-up, and summarizes the domestic and international study of dynamic response and structural strength analysis. Based on the drawings and the jack-up's operation manual, the paper establishes the jack-up's geometric model and finite element model for hydrodynamic and structure calculation in SESAM software and Ansys software. And it calculates the jack-up's dynamic response during emplacement under two kinds of sea conditions, and analysis the leg's final length and driving depth when the collision between the pile shoe and the seabed occurs in SESAM software. According to the soil characteristic, the paper calculates the collision force and takes a security verification of the jack-up after the collision in Ansys software.The result shows that the jack-up can take the emplacement operation safety under the condition that the wind velocity is 21knots, the maximum wave height is 2.5 meter and the wave period is 4 second. And when the wind velocity is 27knots, the maximum wave height is 3.5 meter and the wave period is 5 second, the lifting system will not be damaged. As a result, it is suitable to take the emplacement operation under it.