Special specifications of splicing for a bridge pier having two layers of reinforcement

[saadeh]

Hi All....

Right now I'm preparing shop drawings for a new bridge and I'm having some trouble with the quality of the original drawings made by the designer and I have to figure out a lot of stuff from these poor-low-quality-somehow-useless drawings.

As of now, I'm reconstructing the lost information of the pier's longitudinal reinforcement, the pier has two layers of reinforcement (or lets say two vertical bundled bars with one of them being placed behind the front bar toward the center of the column, not bundled side by side and fixed to the transverse steel reinforcement), what I wanna ask, is there any special specifications for rebar splicing in this case ?? I mean, is it safe to splice all bars (about 92 bars dia. 32mm) in the same location ?? for example and as a starter for the answer, shall I make a staggered splice where half the bars are spliced, for example, in the first 2m of the pier, and the other half in the next 2m ?? and wouldn't that make the splicing region too large and cause other problems ??
2m is just an assumption that i used because these lovely drawings insist on mentioning the (2m) every where !!

Thanks in advance.

 

[bridgebuster]

The way you describe the bars being placed is to ensure sufficient clearance between bars for concrete placement.

ACI 318 Chapters 7 and 12, AASHTO Standard Specifications Chapter 8, & AASHTO LRFD Chapter 5 address bundled bars. US codes require a 25% increase in lap lengths for a two-bar bundle. Yes, you have to stagger the splices. Splices within a bundle cannot overlap.

Check your design code.

 

[ztengguy]

Can you pose this question to the original designer?

 

[chicopee]

I would stagger the splices. When we had new rebar cages made, entire cages would be fabricated in a yard and then transported to, and erected at their destinations, so their would be a minimum amount of field work to complete the works before erecting the concrete formwork around the rebar cages.