To limit the probability of insufficient depth of concrete or masonry for an adequate bond with anchor bolts, which could lead to inadequate withdrawal resistance, which could lead to an inability to resist expected wind loads, which could lead to overturning, lifting, sliding or excessive deflection of the superstructure.
Where building elements are required to provide fire resistance, this is to limit the probability of excessive deflection of the elements, which could lead to compromised fire resistance, which could lead to harm to persons.
To direct Code users to Sentence 9.15.2.3.(4), which contains requirements for piers.