×
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

Stone stormwater diaphrams

Stone stormwater diaphrams

Stone stormwater diaphrams

(OP)
Does anyone have experience with stone filled diaphragms for stormwater retention and filtering? It is a trench along side a road or other facility filled with large washed and screened gravel (0.75-1.5 inches). The intent is runoff enters the diaphragm, particles settle out, and the water percolates into the ground through the trench bottom.

Apparently, our state Dept of Environmental Conservation, who is in charge of NPEDES/SPEDES enforcement, prefers rounded gravel since it will not compact and the voids will remain. The problem is, whenever a vehicle goes off the shoulder, the roundes stones are broadcast all over the shoulder. Luckily, it's an 8' shoulder, so not that many make it into the travel lane, but it is becoming a maintenance headache, and potentially a safety hazard as well.

Can anyone think of a way to bind the gravel together, without compromising its effectiveness as a stormwater treatment practice? I'm wondering if the hydrogel used in CU Structural Soil (TM) would work as a binder. CU Structural soil is a mixture of larged crushed aggregate, topsoil, and hydrogel binder used as a street tree planting medium.

If we used something like rairoad ballast instead of rounded river stone, would we get similar void ratios with better weight-bearing performance and more interlocking between stones?

Thanks in advance!

     "...students of traffic are beginning to realize the false economy of mechanically controlled traffic, and hand work by trained officers will again prevail." - Wm. Phelps Eno, ca. 1928

"I'm searching for the questions, so my answers will make sense." - Stephen Brust

RE: Stone stormwater diaphrams

I've worked on several projects with similar issues, and testing of various RR ballast-like materials (97% between 2- and 3/8- inch) showed 40% void ratio, which is what I would expect in rounded gravel.



RE: Stone stormwater diaphrams

How deep is the trench?  My first thought would be to retain the specified gravel, but install a top layer of smaller crushed  stone as a riding surface.  One could seperate the two with a geotextile if needed.

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