**JACKET + TOPSIDE MODEL – OVERALL VIEW**

**JACKET – SECTIONS**

The 103.5 m height structure has four main vertical legs fixed on the seabed to support the loads. They are braced by five horizontal sets of elements in the Jacket, arranged equally spaced from the structure’s foot to a height of 80 m, and also by diagonal elements in every side of the Jacket. Each horizontal frame has a different size. All the elements have the same properties (S355 steel). Moreover, cans and stubs are applied in the joints to increase the stiffness.

**EIGENVALUE ANALYSIS**

**Eigenvalue analysis** provides dynamic properties of a structure by solving the characteristic equation composed of mass matrix and stiffness matrix. The dynamic properties include natural modes (or mode shapes), natural periods (or frequencies) and modal participation factors. The natural frequencies and the mode shapes of the system can be calculated from an eigenvalue analysis of the undamped free vibration system as shown in the equation:

MODE 1 – f = 0.440868 Hz

MODE 2 – f = 0.454736 Hz

MODE 3 – f = 0.518925 Hz