![Earthquake Lateral Forces according UBC 97: 1 Earthquake Lateral Forces according UBC 97](https://excel.civilmdc.com/wp-content/uploads/2021/12/Earthquake-Lateral-Forces-according-UBC-97.png)
Earthquake forces are called lateral forces because their predominant effect is to apply horizontal loads to a building. Although earthquake waves do impart a vertical component of force to buildings, the weight of the building normally provides sufficient resistance.