06 April 2018 Hi, I was wondering how the riprap apron design values are calculated since they seem to include the slope value which does not appear in the HEC-14 equation from Fletcher and Grace (1972). Regards, Simon
Plainwater
Civil engineers for a better world
NCHRP 568 Riprap Design Criteria, Recommended Specifications, and Quality Control
Author(s): PE Clopper, PF Lagasse, JF Ruff, LW Zevenbergen (Ayres Associates, Inc Fort Collins, CO) Publisher: Transportation Research Board Year: 2006 Link(s): PDF Subjects: Riprap This report presents the findings of a study to develop design guidelines, material specifications and test methods, construction specifications, and construction, inspection, and quality control guidelines for riprap at streams and […]
4,689 total views
River Mechanics
Author: Pierre Y Julien Publisher: Cambridge University Press Year: 2002 Link(s): Google Books Preview Subjects: Riprap, Rivers This textbook offers a thorough mechanical analysis of rivers from upland areas to oceans. It scrutinizes state-of-the-art methods, underlining both theory and engineering applications. Each chapter includes a presentation of fundamental principles, followed with an engineering analysis and […]
4,615 total views, 1 views today
HDS-6 River Engineering For Highway Encroachments
Author(s): E.V. Richardson, D.B. Simons, P.F. Lagasse Publisher: FHWA Year: 2001 Link(s): PDF Subjects: aggradation, degradation, alluvial channel, alluvial fan, river training, geomorphology, headcutting, lateral migration, riprap, sediment transport, scour, stable channel design, countermeasures The Federal Highway Administration document “Highways in the River Environment – Hydraulic and Environmental Design Considerations” was first published in […]
4,125 total views, 1 views today
HEC-11 Design of Riprap Revetment
Author(s): Scott A. Brown, Eric S. Clyde Publisher: FHWA Year: 1989 Links: PDF, SI Version Subjects: Riprap, Revetments, Bank Protection, Gabions, Grouted Riprap, Riprap Design, Precast Concrete Riprap, Paved Linings One of the hazards of placing a highway near a river or stream channel is the potential for erosion of the highway embankment by moving […]
12,546 total views
Caltrans Riprap Sizes
This has been superseded by Caltrans New Riprap Classes. D50 Equivalent Spherical Diameter RSP Class D50Size1 D50Weight inches pounds 8 Ton 71 17600 4 Ton 56 8800 2 Ton 45 4400 1 Ton 36 2200 1/2 Ton 28 1100 1/4 Ton 23 550 Light 16 200 Facing 12 75 Backing No 1 12 75 […]
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FHWA Riprap Size
Source: FP-14 Standard Specifications Author: FHWA Table 705-1 Gradation Requirements for Riprap(1) Class % of Rock Equal or Smaller by Count Range of Intermediate Dimensions,(2) Range of Rock Mass,(3) DX inches (millimeters) pounds (kilograms) 1 100 9 – 15 (230 – 380) 59 – 270 (27 – 120) 85 7 – 11 (180 – 280) […]
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HEC 14: Riprap Apron
10.2 RIPRAP APRON The most commonly used device for outlet protection, primarily for culverts 60 in (1500 mm) or smaller, is a riprap apron. An example schematic of an apron taken from the Central Federal Lands Division of the Federal Highway Administration is shown in Figure 10.4. Figure 10.4. Placed Riprap at Culverts (per Central […]
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HEC-15: Permissible Shear Stress
HEC-15 Section 6.2 – PERMISSIBLE SHEAR STRESS Values for permissible shear stress for riprap and gravel linings are based on research conducted at laboratory facilities and in the field. The values presented here are judged to be conservative and appropriate for design use. Permissible shear stress is given by the following equation: τp = F*.(γs […]
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Manning’s n For Riprap-Lined Channels
HEC-15 Section 6.1 – MANNING’S ROUGHNESS Manning’s roughness is a key parameter needed for determining the relationships between depth, velocity, and slope in a channel. However, for gravel and riprap linings, roughness has been shown to be a function of a variety of factors including flow depth, D50, D84, and friction slope, Sf. A partial […]
11,750 total views
