# Seismic Anchor Movement

When connecting the piping with various large mass (in comparison with the piping) structures, equipment and buildings will be mutual seismic movements of these structures, the effect of which should be considered when calculating the strength of the piping.

Since the building has a very large mass, due to the action of inertial forces, it can move in opposite phase to ground movements, rotate, etc.

If the pipe is in the building and has a point of attachment on different floors or different building structures, it is necessary to take into account forces arising from mutual displacements, which can be obtained based only on building analysis without the piping. It should be borne in mind that this approach is valid, only if the mass and stiffness of the building or the building structure much higher than mass and stiffness of the piping. If the mass and stiffness of the structure is comparable with the mass and stiffness of the piping, the settlement requires simultaneous piping and building structure analysis.

Seismic anchor movements set by the user for any supports in the form of independent linear displacements along the X, Y, Z axes. Restraints must have a rigid or elastic links in each direction. All seismic anchor movements are associated with a particular phase number (grouped support in several phase groups).

For example, all supports attached to the same building structure move synchronously and therefore they are assigned the same phase number. Supports attached to another building structure or to the ground must be assigned to another phase number, as their displacement occur independently of each other.

Calculation of seismic anchor movement is made to determine the forces generated in the piping as a result of the relative displacements of anchors, which can be attached to independent building structures, foundation plates and equipment.

 Property Description Phase group Support phase group name and number Along the X axis Maximum possible support displacement along the X axis Along the Y axis Maximum possible support displacement along the Y axis Along the Z axis Maximum possible support displacement along the Z axis