Transcript 2013_AASHTOware_JCM
Superload Move
April 06, 2013
Prasad Nallapaneni & Jonathan Mallard
Structure and Bridge, VDOT
Superload - Route
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Superload- Details
Total Distance : Approximately 96 Miles Number of Structures: 62 (61 VDOT) Bridges: 25 Culverts: 37 VDOT Structures: Analyzed in-house: 47 Third Party Analysis: 16
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Superload - Detials
Analysis Method: In house: LFR/LRFR –
»VIRTIS if available »Compared Simple span moments with HS20 ratings
Third Party: LRFR -16 Bridges Verified hand calculations / LFR analysis Structures Jumped: 5 (five)
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Superload - Permit
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Superload - Permit
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Superload - Jump
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Superload - Restrictions
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Superload - Crabs
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Superload
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Superload
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Superload
Attempt Made:
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Run few bridges in 6.5 with Non Standard Gage Vehicle
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Compare with calculations received from Third Party and in-house STAAD runs
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Superload
Bridge Fed ID: 24505
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Superload
Bridge Fed ID: 24505 Wheel Configuration: Straight
Dead Load Moment (K ft) Capacity (K Ft) Rating Factor Live Load (K ft)
BrR Model
1550 6271 2.01
2355
Hand Clacs
1519 6221 2.09
2246
% Diff Reason
2.04% 0.80% -4.22% Model has slightly higher Superimposed loads Round of error 4.83% May be round off error in Distribution Factor. No detail output in BrR for Live Load. 14
Superload
Bridge Fed ID: 25334
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Superload
Bridge Fed ID: 25334 Wheel Configuration: Straight
Dead Load Moment (K ft) Capacity (K Ft) Rating Factor Live Load (K ft)
BrR Model
5701 15475 1.11
8805
Hand Clacs
5691 15463 1.19
8233
% Diff Reason
0.18% 0.08% -6.48% Round Off Round Off 6.95% May be round off error in Distribution Factor. No detail output in BrR for Live Load. 16
Bridge 24231
Superload
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Superload
Bridge Fed ID: 24231 Wheel Configuration: Straight
Dead Load Moment (K ft) Capacity (K Ft) Rating Factor Live Load (K ft)
BrR Model
320 1828 2.07
729
Hand Clacs
320 1828 2.19
688
% Diff Reason
0.0% 0.08% -5.6% 5.93% May be round off error in Distribution Factor. No detail output in BrR for Live Load. 18
Superload
Difficulties Faced
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Installation issues with 64 vs. 32 bit Long time run process Memory issues Run only from bridge explorer Not able to get a detailed LL output.
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Superload
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Superload
http://www.youtube.com/watch?v=Dmacnt 5GaHw http://www.youtube.com/watch?v=v8_3uy ecXSc
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Field Operations
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Field Surveys LIDAR survey was taken before and after on 5 long span structures.
Calculated LL deflections from vehicle were up to 6” Survey showed before and after elevations of the bridge deck surface and the bottoms of the girders were within the tolerance of the method used.
Any post move deflection was undetectable from a survey perspective.
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Field Operations
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Structure 10720, Lee County Originally designated to be ‘jumped’ Field review of route raised concerns about limited hospital access for an extended period.
Detour length = 50 miles.
Hauler’s consultants recommended removing a 20 kip counterweight from each of the tractors.
Tractors effectiveness was limited due to traction loss.
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Field Operations
• • • •
Structure 24362, Norton Rated by private consultant. Substructure controlled at pier due to uneven span arrangement Travel restrictions were issued. During transport, hydraulic line broke while crossing the structure. Lead tractor was over critical pier.
After line replacement, vehicle initiated movement from rear tractor, which was not on bridge.
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Field Operations
• • •
Structure 22454, Norton Simple Span Plate Girder with partial depth welded diaphragms First diaphragm on girder 4 cracked at the base.
Retrofitted by drilling, arrested by next inspection cycle.
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