1. MaSSENA LATERAL BRIDGE SLIDE CASE STUDY
Jim Nelson, Iowa DOT

2. Project location
IA 92 over Small Natural Stream, 1.0 mile west of Jct. IA 148

3. Project location

4. Existing structure 40’ x 30’ Steel I-beam Constructed 1930
Reconstructed 1949
Overlay 1968
Retrofit rail 1992
Overlay 1998
1930 plan is 3 sheets
1949 bridge widened and raised. Plan is 3 sheets. Beam is 26 x 85 CB
1998 plan is 9 sheets to overlay bridge
2013 plan is 57 sheets

5. Existing structure Structurally deficient – sufficiency rating is 38.2
Bridge is not adequate for legal loads – posted “One truck at a time.”
Girders have section loss, large areas of severe rust and large areas of pack rust. Deck cracking noted – current sounding of overlay does not indicate delamination.
Abutment – map cracking and random cracking with efflorescence, large delaminated areas, shallow spalls, exposed reinforcing and severe scaling.
54 Timber piling – original plans are illegible on the length. I would assume 40 feet or so.
Stream has degraded 3 feet since the 1949 reconstruction. Scour critical - The footings have been protected with an articulating block mat.
Annual inspections are specified.

6. Proposed replacement bridge
Pretensioned Prestressed Concrete Beam Bridge

7. Mobility impacts Detour traffic for duration of construction
7 miles out of distance travel for detour
AADT (2012) – 1,460 w/ 16% trucks
User costs for 180 day detour
Indirect $437,000
Direct $15,000 (Co. Road Maint. & Detour Signing)
Original concept was 180 day detour. – Reduced to 9 day critical closure with $10,000/day.
We were looking for a solution to that would reduce mobility impact time to what the FHWA describes as a tier 3 ABC solution. Took the mobility impact down from entire construction season of several months to under 2 weeks.
User costs for 9 day critical closure $22,000.

8. Project staging area
120’ BTC (45”) with 6 beam cross section.

9. Utah DOT WANSHIP BRIDGE SLIDE
Utah completed this as a tier 1 project where traffic on Eastbound I-80 over a secondary road was detoured for less than 24 hours.

10. Bridge construction visualization

11. Semi-integral abutment
Abutment Diaphragm Details – sheet number 14

12. Sliding pad Superstructure Details – sheet number 15
Bonded PTFE surface on bearing pad detail

13. Project cost Let April 16, 2013 Winning bid $1.3 Million
Bridge unit cost - $112/SF
Historic bridge unit cost - $85/SF

14. Critical closure schedule

15. Massena lateral bridge slide web site
The web site contains project information, an extended construction visualization, a live project web camera and the contract documents including plans and specifications.

16. Construction progress

17. acknowledgements Designer – Iowa DOT
Constructability Review – Michael Baker Corporation
ABC Peer Exchange – Utah DOT
ABC Detail Testing – Iowa State University
Construction Administration – Iowa DOT
Prime Contractor – Herberger Construction Co., Inc.
Precast Wing Supplier – Cretex Concrete Products
Precast Beam Supplier – Cretex Concrete Products
HfL Grant – FHWA
Baker – Salt Lake City, UT
Herberger Construction Co., Inc. – Indianola, IA
Cretex Concrete Products – West Des Moines