Riprap

[GeoGrouting]

For a 1 m high berm with 1.5H:1 to 2H:1 slopes for flood protection from a ditch with 200-year peak flow of 33 m3/sec. The upstream is going to be protected by riprap. What are the typical dimensions and thickness of such a riprap. Thank you for the feedback in advance.

 

[cvg]

dumped riprap is not recommended for such steep slopes. without a hydraulic analysis first, you can't size any riprap. but given the steep slope and the large discharge, you will need either very large riprap or you will need to grout it

 

[GeoGrouting]

What is the estimated size of a big rock and what thickness of rip rap. Should the thickness, please. Thank you.

 

[francesca]

Grouted riprap is horrible for scour. Anyway, riprap is sized based on velocity not flow rate. There are nomographs in just about every DOT's drainage manual.

 

[gbam]

GeoGrouting - Take a look at Riprap Revetment Design FWHA HEC11

http://www.fhwa.dot.gov/engineering/hydraulics/library_arc.cfm?pub_number=11&id=27

This will walk you through proper revetment design.