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