NICET - Highway Construction Inspection Practice Exam

What distinguishes a pedestal or spill-through abutment from other abutments?

1. It is constructed after the embankment

2. It must be built before the approach embankment

3. It connects rigidly without expansion joints

4. It is taller than traditional abutments

The correct answer is: It must be built before the approach embankment

A pedestal or spill-through abutment is particularly distinguished by the fact that it must be built before the approach embankment. This is critical in ensuring that the structural integrity and the alignment of the bridge or roadway are maintained during construction. The positioning and stability of the abutment play a vital role in supporting the load of the structure and accommodating any hydraulic or lateral forces acting on it. When an abutment is constructed before the approach embankment, it provides a solid foundation for the approaching roadway, which can help in the proper seating of the bridge deck. This order of construction can also facilitate better drainage and reduce the chances of erosion or settling that could impact the stability of both the embankment and the bridge structure. Conversely, while the height of the pedestal or spill-through abutment may vary, it is not inherently taller than traditional abutments, as the design is often determined by specific site conditions and engineering requirements rather than a fixed height differential. Additionally, the construction sequence involving embankments and abutments revolves around ensuring optimal load distribution and alignment rather than the rigid connection without expansion joints.