×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

SD pipes a hazard?

SD pipes a hazard?

SD pipes a hazard?

(OP)
A new residential subdivision has some unfenced storm water detention ponds.  Inlets and outlets are as follows
6-12" smooth PVC inlets connected to catchbasins
1-18" corrugated HDPE outlet from pond to flow-control manhole
2-18" corrugated HDPE inlets to wetland from pond flow control and overflow structures.
1-30" RCP inlet to pond. (RCP runs about 300' to MH and catchbasins upstream.

Upon final inspection, the municiplity wants to protect against children entering the pipes.  The plans call for beveling the pipes (pond bank slopes are about 3:1, and constructing concrete collars with minimum 18" width beyond each side and top of pipe. The subdivision is essentially complete, but the contractor has so far failed to bevel pipe and install collars.
    There are no local or state standards that I am aware of.  The project engineer has proposed bolting some 1/4" x 2" straps to the concrete collars.
Question: are there guidelines or standards for maximum openings allowable for an facility accessible to children such as this?

RE: SD pipes a hazard?

Many jurisdictions require fencing of detention ponds.
Many have details for debris racks which can be placed at inlets, outlets or both.
Machine gun emplacements also discourage children.

RE: SD pipes a hazard?

Less than 9" clear opening, (both ways), is considered child proof.

RE: SD pipes a hazard?

in addition to the safety requirements for children, you may need to check your flow capacities and revise your hydraulic analysis to account for the headloss created by the bars, grates and bevels.  Not only will the bars obstruct the flow, but they may collect trash which can allow the grate to clog even more. Typically I would assume the grate is 50% clogged for my analysis.   You might have less clogging and headloss if you use a vertical headwall instead of a 3:1 bevel. Vertical may also be easier to construct.

RE: SD pipes a hazard?

(OP)
Civilperson or anyone else:
If 9" maximum both ways is considered child proof, what would be the maximum one way, as in parallel bars?  (I probably should be looking at a building code, I guess.)
 

RE: SD pipes a hazard?

stair railings are usually about 4 - 6 inches. if bars go just just one way, remember kids can use a stick to bend the bars and get in. for larger pipes, make the grate "redneck proof" - in other words, strong enough so that a redneck with a 12 pack can't get the grate open. Make the bars heavy enough to prevent bending. In other words, a couple of #4 rebar welded down may not be strong enough.

RE: SD pipes a hazard?

Hove you looked at manufacturers for access gates that can be mounted on the inlet?  For large culverts our State DOT has a generic standard for a hinged gate specifically for this reason.  CVG made a good point, make sure your calcs  account for additional headloss.  It may be easier to enclose the pond.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources