In talking with some guys yesterday we decided that the N value for rip rap which is in the 30ths would be appropriate to use for the sheet flow time of concentration calculation.
We are working with a sports field that has artificial turf, with a clean stone base. Would like some opinions on an appropriate N value to use for the sheet flow until it enters the piping system.
Thanks woofar and ron for you information. The 2006 IRC requires a determination of the expansion index in accordance with ASTM D 4829 or the Atterberg limit info testing. What is your opinion on this test for expansive soil identification and degree of severity?
Thanks-John
Recently I had some soil tested for Atterberg limits for shrink swell determination per the IBC. The testing lab report noted that the plastic limit was zero as they could not get the sample to thread down to the 1/8" requirement. This in turn forced the Plasticity Index to equal the liquid...
Hec-1 with Dam Breach simulation has been accepted by VA Dam Safety in the past. Input information and output analysis utilizes other calculation procedures not in HEC-1; Breach input factors are calculated from NWS Simple Dam Break and Breach Predictor equations. It is my understanding that the...
The state of Virginia's new Impounding Structure Regulations now require a developed PMF Hydrograph for 6, 12 and 24 hour durations with the hydrograph that creates the largest peak outflow to be used to determine capacity for nonfailure and failure analysis. To my knowledge the reviewing...
I need to locate the PC Record(Cumulative Precipitation Time Series) for the 12 hour pmp storm event. I have the 6 hour(51points) and the 24 hour(241points) PC data. When I change the IN value to 1.5 on the 24 hours file and also the PB file for PMP it does not correlate to the 6 hour (51...
