Caltrans New Riprap Classes
Source: Caltran Highway Design Manual, Chapter 870
These supersede the previous Caltrans Riprap Sizes.
Caltrans requires the use of these new RSP gradations starting August 1st, 2016 in new projects and those not yet at 30 percent PS&E stage.
Caltrans Highway Design Manual Table 873.3A
| Nominal RSP Class by Median Particle Size(3) | d15 | d50 | d100 | Placement | |||
|---|---|---|---|---|---|---|---|
| Class (1), (2) | Size (in) | Min | Max | Min | Max | Max | Method |
| I | 6 | 3.7 | 5.2 | 5.7 | 6.9 | 12.0 | B |
| II | 9 | 5.5 | 7.8 | 8.5 | 10.5 | 18.0 | B |
| III | 12 | 7.3 | 10.5 | 11.5 | 14.0 | 24.0 | B |
| IV | 15 | 9.2 | 13.0 | 14.5 | 17.5 | 30.0 | B |
| V | 18 | 11.0 | 15.5 | 17.0 | 20.5 | 36.0 | B |
| VI | 21 | 13.0 | 18.5 | 20.0 | 24.0 | 42.0 | A or B |
| VII | 24 | 14.5 | 21.0 | 23.0 | 27.5 | 48.0 | A or B |
| VIII | 30 | 18.5 | 26.0 | 28.5 | 34.5 | 48.0 | A or B |
| IX | 36 | 22.0 | 31.5 | 34.0 | 41.5 | 52.8 | A |
| X | 42 | 25.5 | 36.5 | 40.0 | 48.5 | 60.5 | A |
| XI | 46 | 28.0 | 39.4 | 43.7 | 53.1 | 66.6 | A |
NOTES:
- Rock grading and quality requirements per Standard Specifications.
-
RSP-fabric Type of geotextile and quality requirements per Section 96 Rock Slope Protection Fabric of the Standard Specifications. For RSP Classes I thru VIII, use Class 8 RSP-fabric which has lower weight per unit area and it also has lower toughness (tensile x elongation, both at break) than Class 10 RSP-fabric. For RSP Classes IX thru XI, use Class 10 RSP-fabric.
-
Intermediate, or B dimension (i.e., width) where A dimension is length, and C dimension is thickness.
Caltrans Highway Design Manual Table 873.3B
RSP Class by Median Particle Weight(3)
| Nominal RSP Class by Median Particle Weight | W15 | W50 | W100 | Placement | |||
|---|---|---|---|---|---|---|---|
| Class (1), (2) | Weight | Min | Max | Min | Max | Max | Method |
| I | 20 lb | 4 | 11 | 15 | 27 | 140 | B |
| II | 60 lb | 14 | 39 | 50 | 94 | 470 | B |
| III | 150 lb | 32 | 94 | 120 | 220 | 1,100 | B |
| IV | 300 lb | 63 | 180 | 250 | 440 | 2,200 | B |
| V | 1/4 ton | 110 | 300 | 400 | 700 | 3,800 | B |
| VI | 3/8 ton | 180 | 520 | 650 | 1,100 | 6,000 | A or B |
| VII | 1/2 ton | 250 | 750 | 1000 | 1,700 | 9,000 | A or B |
| VIII | 1 ton | 520 | 1,450 | 1,900 | 3,300 | 9,000 | A or B |
| IX | 2 ton | 870 | 2,500 | 3,200 | 5,800 | 12,000 | A |
| X | 3 ton | 1,350 | 4,000 | 5,200 | 9,300 | 18,000 | A |
| XI | 4 ton | 1,800 | 5,000 | 6,800 | 12,200 | 24,000 | A |
NOTES:
- Rock grading and quality requirements per Standard Specifications.
- RSP-fabric Type of geotextile and quality requirements per Section 96 Rock Slope Protection Fabric of the Standard Specifications. For RSP Classes I thru VIII, use Class 8 RSP-fabric which has lower weight per unit area and it also has lower toughness (tensile x elongation, both at break) than Class 10 RSP-fabric. For RSP Classes IX thru XI, use Class 10 RSP-fabric.
- Values shown are based on Table 873.3A dimensions and an assumed specific gravity of 2.65. Weight will vary based on density of rock available for the project.