# Rocscience Coefficient of Restitution Table

RN ( Normal ) | RT ( Tangential ) | Type | Verification | Location | Reference
Min | Max | Mean | Standard Deviation | Min | Max | Mean | Standard Deviation |  |  |  |
0.370 | 0.420 |  |  | 0.870 | 0.920 |  |  | Hard surface paving | Tested using simulated rockfalls of similar size and shape of a previous rockfall. | Glenwood Canyon, Colorado, USA | Pfeiffer, T.J., and Bowen, T.D., "Computer Simulation of Rockfalls." Bulletin of Association of Engineering Geologists. Vol. 26, No. 1. 1989. pp135-146
0.330 | 0.370 |  |  | 0.830 | 0.870 |  |  | Bedrock or boulders with little soil or vegetation
0.300 | 0.330 |  |  | 0.830 | 0.870 |  |  | Talus with little vegetation
0.300 | 0.330 |  |  | 0.800 | 0.830 |  |  | Talus with some vegetation
0.280 | 0.320 |  |  | 0.800 | 0.830 |  |  | Soft soil slope with little vegetation
0.280 | 0.320 |  |  | 0.780 | 0.820 |  |  | Vegetated soil slope
|  | 0.315 | 0.064 |  |  | 0.712 | 0.116 | Limestone face | Tested on restoration-blasting slopes made of four types of materials; blast-generated rock fragments, partially vegetated scree on berms, uncovered blast piles, and vegetated quarry waste. | Limestone quarry in England | Robotham, M.E., and Wang, H., and Walton, G., "Assessment of risk from rockfall from active and abandoned quarry slopes." Institution of mining and Metallurgy, Section A. 1995.104(Jan-April), pp A25-A33
|  | 0.303 | 0.080 |  |  | 0.615 | 0.170 | Partially vegetated limestone scree
|  | 0.315 | 0.064 |  |  | 0.712 | 0.116 | Uncovered limestone blast pile
|  | 0.251 | 0.029 |  |  | 0.489 | 0.141 | Vegetated covered limestone pile
|  | 0.276 | 0.079 |  |  | 0.835 | 0.087 | Chalk face | Chalk quarry in England
|  | 0.271 | 0.018 |  |  | 0.596 | 0.085 | Vegetated chalk scree
|  | 0.384 | 0.133 |  |  | 0.687 | 0.130 | Wood platform slope at 45 degrees was used as a control for the field tests they did. | Tested as control parameters | Western North Carolina for Interstate 40. | Wu, Shie-Shin "Rockfall evaluation by computer simulation" Transportation Research Records. Vol. 1031 pp 1-5, 1985.
|  | 0.200 |  |  |  | 0.530 |  | Dolomitic limestone boulders on rocky surfaces and on talus desposits | Consisted of hand made throws and free fall tests by fragmentation of rock using explosives, of dolomitic limestone boulders on rocky surfaces and on talus deposit of the landslide fans. Also used back-analysis, and information from Urciuoli. | Atrani, Campania, Southern Italy | Budetta, P., and Santo, A. "Morphostructural evolution and related kinematics of rockfalls in Campania(southern Italy)." Engineering Geology. Vol.36 pp197-210.
|  | 0.100 |  |  |  | 0.200 |  | Remolded pyroclastic from the terraces situated at the base of the cliff
|  | 0.000 |  |  |  | 0.240 |  | Impacts on detritus of the fans present at the foot of a rock cliff
|  | 0.393 |  |  |  | 0.567 |  | Soil | Tested by dropping 3 to 5 cm cuboid and angular granite rock fragments onto slopes | Hong Kong | Chau, K.T., and Wong, R.H.C., and Lee, C.F. "Rockfall Problems in Hong Kong and some new experimental results for coefficients of Restitution" International Journal of rock mechanics and mining sciences and geomechanics. Vol. 35, Section 4-5. 1996. pp662-663
|  | 0.453 |  |  |  | 0.737 |  | Shotcrete
|  | 0.487 |  |  |  | 0.910 |  | Rock slope
|  | 0.500 |  |  |  | 0.950 |  | Bedrock | Referenced from tests carried out by Barbieri et al. | Italcementi works at Castellammare di Stabia(northern slope of the Sorrentine Peninsula), and the area of Atrani. | Giani, G.P. "Rock Slope Stability Analysis" Rotterdam, Balkema 1992.
|  | 0.350 |  |  |  | 0.850 |  | Bedrock covered by large blocks
|  | 0.300 |  |  |  | 0.700 |  | Debris formed by uniform distributed elements
|  | 0.250 |  |  |  | 0.550 |  | Soil covered by vegetation
|  | 0.530 |  |  |  | 0.990 |  | Clean hard bedrock |  |  | Hoek, Evert. "Unpublished notes" NSERC Industrial Research Professor of Rock Engineering, Department of Civil Engineering, University of Toronto, St George Street, Toronto, Ontario, Canada M5S 1A4
|  | 0.400 |  |  |  | 0.900 |  | Asphalt roadway
|  | 0.350 |  |  |  | 0.850 |  | Bedrock outcrops with hard surface, large boulders
|  | 0.320 |  |  |  | 0.820 |  | Talus cover
|  | 0.320 |  |  |  | 0.800 |  | Talus cover with vegetation
|  | 0.300 |  |  |  | 0.800 |  | Soft soil, some vegetation
0.370 | 0.420 |  |  |  |  |  |  | Smooth hard surfaces and paving | Developed by observation and literature review | Colordado, USA | Pfeiffer, T.J., and Higgens, J.D., "Rockfall Hazard Analysis Using the Colorado Rockfall Simulation." Transportation Research Record 1288, TRB, National Research Council, Washington, D.C., 1990, pp117-126.
0.330 | 0.370 |  |  |  |  |  |  | Most bedrock and boulder fields
0.300 | 0.330 |  |  |  |  |  |  | Talus and firm soil slopes
0.280 | 0.300 |  |  |  |  |  |  | Soft soil slopes
|  |  |  | 0.870 | 0.920 |  |  | Smooth hard surfaces such as pavement or smooth bedrock surfaces
|  |  |  | 0.830 | 0.870 |  |  | Most bedrock surfaces and talus with no vegetation
|  |  |  | 0.820 | 0.850 |  |  | Most talus slopes with some low vegetation
|  |  |  | 0.800 | 0.830 |  |  | Vegetated talus slopes and soil slopes with spares vegetation
|  |  |  | 0.780 | 0.820 |  |  | Brush covered soil slope
|  | 0.530 | 0.040 |  |  | 0.990 | 0.040 | Clean Hard Bedrock | a) rolled many rocks down the slope to verify used values b) comparison to historical rockfall events at site | Mountain road, near Bolzano, Sothtyrol, Italy | feedback from user of RocFall version 3
|  | 0.350 | 0.040 |  |  | 0.850 | 0.040 | Bedrock outkrop
|  | 0.320 | 0.040 |  |  | 0.820 | 0.040 | Talus cover
|  | 0.320 | 0.040 |  |  | 0.800 | 0.040 | Talus with vegetation
|  | 0.400 | 0.040 |  |  | 0.900 | 0.040 | Asphalt paving
|  | 0.530 | 0.040 |  |  | 0.990 | 0.040 | Clean Hard Bedrock | default program values used | 170m deep open pit, Tasmania, Australia (overall pit angle between 55 and 65 degrees) | feedback from user of RocFall version 3
|  | 0.350 | 0.040 |  |  | 0.850 | 0.040 | Bedrock outcrop
|  | 0.480 | 0.190 |  |  | 0.530 | 0.170 | Concrete | inverse calculation of paths - standard deviations seemed to large | Takamatsu, Japan | feedback from user of RocFall version 3
|  | 0.470 | 0.300 |  |  | 0.550 | 0.230 | Weathered Rock
|  | 0.480 | 0.000 |  |  | 0.530 | 0.000 | Concrete | inverse calculation of paths, roughness of 7.9 degrees for concrete, 9.3 for rock
|  | 0.470 | 0.000 |  |  | 0.550 | 0.000 | Weathered Rock
|  | 0.850 | 0.000 |  |  | 0.530 | 0.000 | Concrete | inverse calculation of paths
|  | 1.000 | 0.000 |  |  | 0.550 | 0.000 | Weathered Rock
|  | 0.530 | 0.040 |  |  | 0.990 | 0.040 | Bedrock | Estimation, block diameters 10 to 30 cm | Fjord valley, State of Sogn og Fjordane, Norway | feedback from user of RocFall version 3
|  | 0.500 | 0.060 |  |  | 0.700 | 0.060 | Blockfield
|  | 0.500 | 0.060 |  |  | 0.650 | 0.060 | Blockfield with bushes and small trees
|  | 0.500 | 0.060 |  |  | 0.500 | 0.060 | Blockfield with forest
|  | 0.300 | 0.060 |  |  | 0.800 | 0.060 | Top-soil with vegetation
|  | 0.400 | 0.040 |  |  | 0.900 | 0.040 | Asphalt paving
|  | 0.350 | 0.040 |  |  | 0.850 | 0.040 | Gravel road
|  | 0.500 |  |  |  | 0.800 |  | Sparsley forested slope is covered by a veneer of very fine weathered talus derived from weak shistose units underlying the limestone cap. | Calculated from historic rockfall | Sunnybrae, (interior of )British Colombia, Canada | Hungr, O. and Evans, S.G. 1988. Engineering evaluation of fragmental rockfall hazards. Proc. 5th International Symposium on Landslides, Lusanne. July 1988, Vol. 1, pp. 685-690.
|  | 0.500 |  |  |  | 0.800 |  | Limestone on bare uniform talus slope formed of basalt fragments with a modal size of 5 cm. | Calculated from historic rockfall | Hedley, (southern interior of ) British Colombia, Canada
|  | 0.700 |  |  |  | 0.900 |  | rectangular bolder of metamorphosed tuff on bare rock and a steep snow covered shelf. | Calculated from historic rockfall | Squamish Highway, north of Vancouver British Colombia, Canada