Can Friction Pendulum Bearing (FPB) AKA. Friction Pendulum System (FPS) suppresses the effect of an earthquake from every direction or only from one direction?
Please take a look at the tests which seem to be made from only one direction. Tectonic hazards/Shake-table
Here's an article about triple-PDB systems which has some nice diagrams of each level within the system. From one of the pictures, it seems clear that the circumferential symmetry means a PDB handles vibrations in at the very least all axes in the plane.
from the article,
The Triple Pendulum™ isolator's inner pendulum consists of an inner slider that slides along two inner concave spherical surfaces. Properties of the inner pendulum are typically chosen to reduce the peak accelerations acting on the isolated structure and its contents, to minimize the participation of higher structure modes, and to reduce structure shear forces that occur during service level earthquakes.
