Nebraska Flooding Emergency Case Study

Acrow Reopens Critical Routes After Midwest Flooding

Detours providing relief to residents and first responders in northeast Nebraska

Major flooding in the Midwestern U.S. beginning in early March 2019 caused loss of life and massive property damage across five states. In northeast Nebraska, the Spencer Dam on the Niobrara River failed, releasing a surge of water, collapsing sections of road and three bridges downstream. In order to mitigate further economic losses and to reestablish safe and reliable routes for residents and first responders during the lengthy rebuilding, two detour bridges were ordered from Acrow.

Components for the projects began shipping in early July. The first bridge was constructed on Highway 281 in the Spencer Dam/Niobrara River area and consists of six spans of 100´ each with an 18´ roadway width. The second detour bridge is on Highway 12 west of the Village of Niobrara and also contains six 100´ spans, but with a 24´ width.

The Highway 281 bridge reopened on July 29 and the Highway 12 bridge on August 13. It is anticipated
the bridges will be in use for 12 to 16 months until the permanent structures are completed.

The bridge for Highway 281 was rented from Acrow, while the Highway 12 bridge was purchased. The purchased components will be warehoused by the state for future planned or emergency projects.

 

Nebraska Flooding Emergency Case Study Length of each bridge:
  • Six spans of 100' for a total length of 600'.
Bridge width:
  • The Highway 12 bridge is 24' wide.
  • The Highway 281 bridge is 18' wide.
Live load:
  • 2 lanes of HL-93
  • TL-2 Guardrail load
Deck surface:
  • Aggregate anti-skid epoxy
Bridge design
  • (A) Panel chords, diagonals & verticals, panel reinforcing chords and rakers to AASHTO M223 Gd 65
  • (B) Decking, raker brace, transom, diagonal brace, chord brace, swaybrace, transom brace to AASHTO M223 Gd 50
  • (C) Panel pins to ASTMA A 193 Gd B7
  • (D) Bolts to AASHTO M164M - A325
Bridge finish:
  • All major components galvanized to AASHTO M111-ASTM A123
  • All bolts are hot dipped galvanized
  • All pins are electro galvanized