Return Walls in Bridges & Culverts: Location & Function

Return walls (also called return wing walls or abutment returns) are the short wall segments that connect the wing walls to the abutment stem at each end of a bridge or culvert.

Where They Sit

• Plan view: At the four corners of the structure (two per abutment).
• Elevation: Vertical or stepped, extending from the abutment face back into the embankment.
• Connection: They tie the wing wall (which retains approach fill) to the abutment (which supports the superstructure).

Primary Functions

1. Structural continuity: Transfer earth pressures from wing wall to abutment.
2. Embankment retention: Prevent approach fill from spilling around the abutment ends.
3. Scour protection: Guide flow parallel to abutment, reducing turbulence at corners.
4. Construction joint: Often a designated pour break between wing and abutment.

Typical Geometry

• Length: 1.5–3 m (5–10 ft) typical.
• Thickness: Matches wing wall (0.3–0.5 m).
• Reinforcement: Dowels into abutment stem; vertical/horizontal bars per design.
• Finish: Often exposed architectural concrete or stone veneer matching wing walls.

Culvert Specifics

On box culverts, return walls are the upstream/downstream extensions of the barrel walls that retain the roadway embankment. They may be integral (monolithic pour) or keyed construction joints.

Inspection Points

• Cracking at return/abutment interface (differential settlement).
• Erosion behind return (failed backfill drainage).
• Joint leakage (water staining, efflorescence).
• Impact damage (vehicle strikes on exposed corners).

Small but critical: return walls are the structural handshake between the bridge/culvert and the roadway embankment.