Design of standees - When is design by an engineer required? 2

[cliff234]

For many years we have required standees supporting top reinforcing steel located more than 4’ above the bottom of a member to be designed by an engineer hired by the contractor. Someone in our office asked me where this requirement came from – and I can’t remember. I know I did not arbitrarily make the requirement up. Is this requirement familiar to anyone? And if so, do you know where it came from?

 

[hokie66]

No, but it makes sense. It is a worker and inspector safety issue if standees collapse. You would think that there would have been a standard developed by now...there seems to be a standard for everything.

 

[GC_Hopi]

The references I see for design of standees are CRSI 10-MSP - Manual of Standard Practice and ACI SP-66 - ACI Detailing Manual. I don't have immediate access to those so I can not point to anything specific.

 

[phamENG]

I've never seen that spec'd, but it does make good sense. As hokie mentions, workers and inspectors will often walk on tied cages. This is especially true if walking on the ground/bottom form is impossible due to the cage size or configuration. Collapse of a large cage could kill or seriously injure somebody trapped in the jumble of steel.

 

[dhengr]

Cliff234:
If we want the construction industry, and the people within it, to operate/perform properly and safely, and for engineering to be deployed property within the industry, we need a whole lot more people within that industry who have a vague idea when some engineering help is needed, rather than ignoring that need to save the contractor a buck. The construction people and their management have a significant responsibility at ever level of a project, and the idea that ‘nobody told me or showed me a code para. saying so’ should be damn near criminal. Every imaginable construction situation or detail in the whole universe is not always covered by its own bldg. code sections, with ‘pitchers,’ since most of them seldom really read or understand the real intent of the code anyway. But, they are being paid to know their part of the business with some degree of competency, and without someone else continuously holding their hand, or backstopping them as the insurer of last resort.

 

[Settingsun]

Any instances where this has been a problem? Cages always seem solid (but I'm the last to walk on them) and stick-built ones insitu would probably be noticed if they started to get floppy while being assembled. Pre-built cages that are lifted into place do get designed.

 

[blihpandgeorge]

collapse of reinforcement cages happens too regularly, some good info on the CROSS website

[URL unfurl="true"]https://www.cross-safety.org/uk/safety-information/cross-safety-report/collapse-reinforcing-cage-941[/url]

and the attachement at this link is also helpful

https://www.twforum.org.uk/viewdocu...7a2-46c2-9d49-4c764afaa815&DefaultView=folder

Link

there is also UK / US and Australian versions of CROSS website