NICET - Highway Construction Inspection Practice Exam

What is a defining feature of stub or perched abutments?

1. They are longer than traditional abutments

2. They are constructed before the embankment

3. They allow for compaction of embankments without disruption

4. They function with complicated expansion joints

The correct answer is: They allow for compaction of embankments without disruption

Stub or perched abutments are specifically designed to support bridge structures while minimizing disturbance to the surrounding embankment. One of their key characteristics is that they provide an elevation that allows for full compaction of the embankment material around them. This enables the embankment to be constructed and properly compacted, thereby ensuring stability and integrity without undermining the structure itself. In this design, the abutment itself does not interfere with the process of compacting the embankment, which is crucial for the long-term performance of the bridge and the surrounding roadway. This feature is particularly important in maintaining the balance and strength of the structure, as well as in preventing future settlement or other issues that could arise from a poorly compacted embankment. Understanding this feature helps to realize how stub or perched abutments play a vital role in highway construction, especially in facilitating proper construction techniques that maintain the quality and safety of infrastructure.