Calculating particulate entrainment from riprap
Calculating particulate entrainment from riprap
(OP)
I've been using an equation from Izbash(1970) to help predict stable stone sizes for riprap which could undergo river flow rates of up to 10m/s, unfortunately, the resultant Dn sizes seem rediculously large. Is there a better more realistic formula for estimating the size at these high flow rates?





RE: Calculating particulate entrainment from riprap
RE: Calculating particulate entrainment from riprap
USACE has a design method you can use to verify your calculations, it is available online.
Publication Number: EM 1110-2-1601
Title: Engineering and Design - Hydraulic Design of Flood Control Channels
http://1
RE: Calculating particulate entrainment from riprap
With regards to the calculation, the formula requires larger rock sizes in a linear fashion relative to flowrate. However, as I understand it, the rocks are sized at a nominal diameter and are assumed to be spheres for the convenience of the calc. This does not produce a linear increase in weight relative to the linear requirements for larger diameter rocks, therefore at 10m/s an average rock size of 7m dia is required, weighing in at 511te, which seems a tad heavy to me...I've added a pic. of the bank in question
RE: Calculating particulate entrainment from riprap
RE: Calculating particulate entrainment from riprap
RE: Calculating particulate entrainment from riprap
PS I've calculated a flowrate of 2.7m/s gives a stone Dn of o.4m
RE: Calculating particulate entrainment from riprap
RE: Calculating particulate entrainment from riprap
RE: Calculating particulate entrainment from riprap