Superload Move April 06, 2013 Prasad Nallapaneni & Jonathan Mallard Structure and Bridge, VDOT Superload - Route 2 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 3 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) 4 Superload - Permit 5 Superload - Permit 6 Superload - Jump 7 Superload - Restrictions 8 Superload - Crabs 9 Superload 10 Superload 11 Superload Attempt Made: • Run few bridges in 6.5 with Non Standard Gage Vehicle • Compare with calculations received from Third Party and in-house STAAD runs 12 Superload Bridge Fed ID: 24505 13 Superload Bridge Fed ID: 24505 Wheel Configuration: Straight Dead Load Moment (K ft) Capacity (K Ft) Rating Factor Live Load (K ft) BrR Model Hand Clacs 1550 1519 6271 2.01 6221 2.09 2355 2246 % Diff Reason Model has slightly higher Superimposed loads 0.80% Round of error -4.22% May be round off error in Distribution Factor. No 4.83% detail output in BrR for Live Load. 2.04% 14 Superload Bridge Fed ID: 25334 15 Superload Bridge Fed ID: 25334 Wheel Configuration: Straight Dead Load Moment (K ft) Capacity (K Ft) Rating Factor Live Load (K ft) BrR Model Hand Clacs % Diff 5701 5691 0.18% 15475 1.11 15463 1.19 0.08% -6.48% 8233 May be round off error in Distribution Factor. No 6.95% detail output in BrR for Live Load. 8805 Reason Round Off Round Off 16 Superload Bridge 24231 17 Superload Bridge Fed ID: 24231 Wheel Configuration: Straight Dead Load Moment (K ft) Capacity (K Ft) Rating Factor Live Load (K ft) BrR Model Hand Clacs % Diff 320 320 0.0% 1828 2.07 1828 2.19 0.08% -5.6% 688 May be round off error in Distribution Factor. No 5.93% detail output in BrR for Live Load. 729 Reason 18 Superload Difficulties Faced • 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. 19 Superload 20 Superload http://www.youtube.com/watch?v=Dmacnt 5GaHw http://www.youtube.com/watch?v=v8_3uy ecXSc 21 Field Operations 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. 22 Field Operations 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. 23 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. 24 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. 25 26