Recent content by zebco

Good Morning Guys, haven't posted in a while. Need some input for a new client. He wants to build several 5'deep x 16' wide x 40' long above ground tanks on an existing slab. All being poured concrete and inside a soon to be heated building/ warehouse. I need some design help. Of course...

Thanks for the reponses. My computer got a virus and crashed badly. I think I'll have to start over anyway.

See my post above about anal retention from hell. I'm talking Chapel Hill, NC. They actually believe what ever the calculator will produce is the gospel. They want drainage areas in square feet instead of the standard acre. The entire design approach was never intended for that accuracy. So...

It's all about retaining the flow and the volume to predevelopment conditions. The rational method is only used to determine peak discharge. From that Tp is derived through the posted formula. I'm thinking about just "forcing" the time to peak back to the Tc, or 5 minutes, which seems...

Well the spreadsheet did not post , I'll try it herehttp://files.engineering.com/getfile.aspx?folder=b3c7ff5d-daf6-45ea-859f-211e0ef1de3f&file=roadway_test.xls

here is my spreadsheet and graph. The volume under the Hydrograph is Vol = 1.39*Qp*Tp Qp = peak dischrge Tp = Time to peak flow This is derived from an SCS dimenionless unit hydrograph. (look up McCuen 1982) The spreadsheet solve for Tp. aka 4 min. and 26 min. The Q* you see on the...

Actually, I'm using the curve numbers (CN). I'll supply more info when I get back to my machine at home. Its all inside excel.

The Tc does decrease from pre to post. I'll have to post the formulas later tonight, I'm at work without the info.

Concerning roadway abandonments: I work for a DOT. Typically when we abandon a roadway; we are in fact only abandoning maintenance. The road will always still exist, but we no longer have any interest in it. In my state, the local county commissioners are the governing body that can declare...

I guess I need some reassurance or correction. I'm developing hydrographs. I've got a project under review, the Tp or times to peak are being questioned, I kinda question them too. Scenario, 0.22 acre site, pre-development is all woodland (0.4C), post-development is a roadway with C&G...

Thanks guys, since I'm in a quarry, I think I'll create a sump/dissapator pad of granite in the invert.

Thanks for the reply, my thoughts too on reinforcement. Have you got a diagram of the sump you mentioned?

Looking for design info. for a catch basin/ drop inlet approx. 30 feet deep, feeding a 42" outlet pipe. This is for a quarry reclaimation plan. What kind of info. or standard drawings are out there? I seem to see that most standards limit the height to 10-12 feet. Also, are there any major...

Thanks for the comments, two catch basins / yard inlets will handle all the flow with ease.

dynamics5, my first thoughts for 1/2" cracks is to use some concrete patch materials that are available, and just fill them in and trowel finish. Undermining is always a potential problem with paved ditches, most in NC have switched to rip-rap with a geo-fabric underneath. I would not avise...