Lonnie V. Ragsdale, P. E., TxDOT David Griffin, Proj. Mgr, Texas Sterling Constr Co.
SLIDE-IN-BRIDGE FREDERICKSBURG ROAD AT MEDICAL DRIVE, SAN ANTONIO, TX
Constraints:
Medical Drive could not be closed. Had to have minimum one lane open in each direction at all times for emergency vehicle access to medical facilities.
Milestone 1: Fredericksburg Road could only be closed for 14 days maximum to install bridge.
Milestone 2: Project to be completed in 400 work days (6-day work week).
ADT: Fred. Rd (2008) = 43,900
Med. Dr. (2012) = 18,200
STATS:
First bridge slide in Texas. Each half of the bridge was slid 184 ft – 9 in Longest slide in U. S.*
Each half of the bridge weighed 2,043,000 lbs Heaviest slide in U. S.*
* For the slide method employed.
Setting first beam
2nd Box Beam – Two Crane Pick
First crane swiveled while other walked
Swinging beam around for placement
Ready to lower into place
Beam set in place
Looking East
All Beams in Place
Deck steel in place
Beginning of Deck Placement
Deck Concrete Placement
Second (Larger) Pump Ready
Teflon pads in place under slide shoes – two each slide shoes on each abutment for each bridge half.
Slide Slab and Bridge Abut
Pad made of neoprene with a Teflon surface fused to it. Shoe is armored with a stainless steel plate cast into the concrete
Close up of Slide Shoe and Teflon Pad
Lubricant (Dawn) applied to further reduce friction and prevent damage to the pads.
Applying the “Special” Lubricant
Needed to ensure uniform pressure to the jacks during lifting and sliding operations.
Central Pump used for the Hydraulic Jacks
100 ton jacks used to slide each bridge half – one on each abutment
Hooking up horizontal jacks for 1st half
Cleaning hydraulic ports with brake cleaner to ensure no contaminants
Close up of sliding jack
Anchor block provides resistance as jack pushes / pulls on the dywidag bar
Close up of downstream anchor block and dywidag bar
Damage from plate studs cast into shoe.
Slide Shoe after Slide
Dozer used to ensure bridge half didn’t slide laterally and stayed on center of the slide slab
Small dozer used during slide
Looking eastward. West anchor block in foreground.
Slide Operations Complete
Fredericksburg Road at Medical Drive
Slide – In – Bridge Project
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