To limit the probability that, during construction, the sides of the unsupported excavation will not be stable, which could lead to excessive displacement of ground, which could lead to damage to adjacent buildings.
To direct Code users to the requirements of Articles 4.2.5.1. and 4.2.5.2. with respect to design and construction of unsupported excavations.
To exempt unsupported excavations from the requirements of Sentence 4.2.5.3.(1).