Handhole enclosures must be designed to withstand which of the following?

Handhole enclosures are crucial for providing access to underground utility systems, and as such, they must be engineered to handle a variety of loads. When stating that they must be designed to withstand "all loads likely to be imposed on them," it emphasizes the need for these enclosures to have a robust construction. This requirement ensures safety and longevity in their installed location, as handhole enclosures can be subjected to traffic, heavy machinery, and natural environmental factors.

The design must account for various scenarios such as the weight of passing vehicles, the potential for soil settlement, and even the effects of nearby construction activities. This comprehensive approach to load consideration mitigates the risk of damage to the enclosure or the infrastructure it protects. In contrast to other options, which may only cover specific aspects of load-bearing (like just traffic loads or machinery), this choice captures the broader responsibility of ensuring the integrity of the enclosure regardless of the specific conditions it might encounter.