The craks are apparently a structural (shear) due to almost complete lack of shear reiforcement in the pile cap. The #4 stirrups at 30" o.c. look inadequate. Applying expoxy filler is pointless, as this is cosmetic repair only.
[u]Are the same cracks at the other face of the plie cap?
Some of the most important drawings are conveniently missing - the piling plan, type of the piles used (looks like "Franki" piles), diameter, and the most important the location and exact composition
of the foundations - the beams listed suggest that some of the columns were supported by them...
The sudden collapse of relatively new RC concrete frame building is unusual. As the failure appears to be related to the crushing of
one or more concrete columns at the garage level the plausible reason is salt weathering of concrete. Concrete spalling due to the corrosion of rebars
should be...
The composite action of precast decks is actually quite simple - holes in the precast planks where the shear studs are located, filled with HS grout. The quality of the fill in between planks is critical, as these shall be done extremely well. To avoid locking DL in the steel the span shall be...
The shop welds in a railway bridge shall be grinded smooth and x-rayed - so much for good workmanship. Any irregularity in the tension elements acts as a stress riser
The smaller top flange was due to assumed composite action of precasted deck. With the deteriorated joint that was not the...
The failure was sudden, so definitely it was fatigue cracking of the butt weld across the bottom flange - category E' by AASHTO ( 2.5 ksi constant amplitude fatigue threshold). Anyway, although shop welding of the elements of the railway bridge is permitted in controlled environment and with the...
I did some soundings years ago with mixed results. It helps to find the areas delaminated, but it only allows for performing repairs immediately required, while leaving already corroding areas undetected.
Measuring and mapping the electro potential of the top rebars could be helpful, as the...
Hi Hookie66 & FYE,
I 100% agree that there are few examples of RC or PRC trusses used as bridges, and definitely none with deck and canopy used as top and bottom chords. So, the bridge was definitely a novel structure, designed using wrong code, with the initial S.F. close to 1.3-1.35 at...
@Mike
There will be no issue with the design - the decks on the PC bulb tees are designed as a hinged slab, so some extra reinforcement in the slabs would be required - but the increase of the spans will be gradual.
With the hinged slab approach, the issue of the uplift in the acute corner is...
AASHTO may have some reference, but typical seals shall be durometer 60. To convert to the Young modulus use these formulas: https://en.wikipedia.org/wiki/Shore_durometer
In typical bridge design these forces are disregarded, as their magnitude is irrelevant to the...
This bridge, as I recall,have both internal and external tendons, so some addition or replacement of tendons is more than feasible, without replacing the span - I do not think that it will take more that two weeks to fix the bridge - FL DOT has replaced some tendons in other bridges in the past...
The locations of the cracks at the segments' joints may indicate corrosion of the "stiff" reinforcement located too close to the segment edge, causing the spalling.
Unfortunately I do not have the drawings of the bridge anymore, but some years ago these were used as a guide to design similar...
Yes, it's a segmental box bridge, post tensioned, the segments were match casted and connected using grout and post tensioning. Looks like some of the bottom cables have corroded, and the span is ready to go..
The entire cross section shall be always in compression, so any crack appearing calls...
The bridge could be designed as a single structure using guided pot bearings aligned according to the vectors of expansion - this actually shoul be done for any wide bridge, say above 4 lanes. The design done with assumption that the structure is expanding/contracting only in longitudinal...
The splice is definitely not a design error - that's so called Gerber beam, and the splice is located at or near zero DL moment. Design assumption was that only shear will be carried, with the connection plates forming a plastic hinge.
Rod,
I'm unaware of any manufacturer of such joints, but will ask my Japanese friend. Anyway, it's easy manufacturing, some machining required.
Other option could be to attach one side of the finger joint assembly with bolts designed to shear off. I'm sure it will work - it worked just fine on...
