What type of wall may be directly buried with selected backfill for straight runs?

The correct choice pertains to the classification of walls used in underground applications, specifically regarding their structural capacity to withstand lateral earth pressures. Type C walls are typically designated for use in environments where there are straight runs and where the structural integrity can be enhanced by the inclusion of selected backfill.

The term "Type C" indicates that these walls are designed to handle less compacted earth conditions and are suitable for direct burial applications. Their design allows for more flexibility in placement and enables them to accommodate selected backfill that can provide additional support during installation and over time.

It is crucial to have the right type of wall according to the soil conditions and the surrounding environment, as this affects the overall durability and performance of the burial structure. Properly selecting a Type C wall ensures optimal load distribution and minimizes potential structural failure, which is essential for maintaining the integrity of infrastructure placed underground.