NICET - Highway Construction Inspection Practice Exam

What characterizes a mechanically stabilized abutment?

1. It uses lightweight materials for support

2. It employs reinforced backfill to support bridge seats

3. It has no direct connection to the bridge seat

4. It is primarily designed for pedestrian bridges

The correct answer is: It employs reinforced backfill to support bridge seats

A mechanically stabilized abutment is characterized by its use of reinforced backfill, which plays a critical role in supporting bridge seats. This reinforcement typically consists of geogrids, soil reinforcement layers, or other structural materials that enhance the stability and load distribution of the backfill. By mechanically stabilizing the backfill, the abutment can effectively transfer the loads from the bridge to the ground, thereby ensuring that the structure can withstand various forces, such as those from traffic or environmental conditions. This use of reinforced backfill is essential for maintaining the structural integrity of the bridge, especially in varying soil conditions or under heavy loads. It is also significant for the overall performance of the abutment in preventing excessive settlement or lateral movement, ensuring a stable foundation for the bridge seat. Understanding this concept is crucial for highway construction inspection, as it highlights the importance of proper design and materials in bridge abutment construction to ensure safety and longevity.