This study presents a seismic risk assessment of toppling in electrical equipment supported at its foundation caused by near-fault and far-field ground motions Mexico, for sites located on firm soil. A set of nine electrical equipment ranging in height from 3.0 to 5.08 m, block angle from 18.7 to 34.6 degrees, rigid block frequency parameters from 1.54 to 2.16 rad/s, and sizes from 1.58 to 2.49 m are used. Three conditions are analyzed 1) equipment simply supported on the foundation; 2) equipment anchored to the foundation; and 3) equipment supported on a seismic base isolator. The levels to achieve the failure and reliability of the toppling risk of each of the three conditions studies are computed. The study demonstrates that the mean annual rates of failure decrease monotonically with increasing block angle for both sites and the three conditions studied. This investigation concludes that the reliability for free-standing equipment due to nearfault ground motions is slightly higher than for equipment anchored to the foundation or equipment supported on a seismic base isolator. However, for equipment under the ground motions originated in a far-field source, the reliability for anchored equipment is slightly higher than for free-standing equipment or equipment supported on a seismic base isolator.
