Dynamic Friction and Rolling Friction Coefficients Table

Dynamic Friction Coefficient				Rolling Friction Coefficient				Reference Information
Min	Max	Mean	Standard Deviation	Min	Max	Mean	Standard Deviation	Type	Verification	Location	Reference
						0.4		rock (limestone)	Values adopted for calibration of computer program at ISMES	Strozza, Italy	Azzoni, A., and de Freitas, M.H. (1995) "Experimentally Gained Parameters, Decisive for Rock Fall Analysis". Rock Mechanics and Rock Engineering. 28(2)111-124.
						0.55		hard debris (earth and angular rock fragments with some boulders, compacted)
						0.75		soft debris (angular rock fragments and earth with some boulders, loose)
						0.6		medium debris (medium debris covering smooth rock, compacted)
						0.6		soft debris (earth with rock fragments, loose)
						0.85		mud in the ditch
						0.6		yard (artificially compacted ground)
						0.40-0.45		rock (limestone)	0.3 m3 block size	parameters evaluated both through back analysis and elaboration of in situ tests carried out at Strozza, Italy.	Azzoni, A., La Barbera, G., and Zaninetti, A. (1995) "Analysis and Prediction of Rockfalls Using a Mathematical Model". Int. J. Rock Mech. Min. Sci. & Geomech. Abstr. 32(7)709-724.
						0.50-0.60		fine angular debris and earth, compacted (gravel and cobbles, dia < 20cm)
						0.70-0.80		fine angular debris and earth, soft
						0.60-0.70		medium angular debris with angular rock fragments (20-40cm)
						0.70-1.00		medium angular debris with scattered trees
						0.65-1.20		coarse angular debris with angular rock fragments (40-120 cm dia)
						0.55-0.65		earth with grass and some vegetation
						0.85		ditch with mud
						0.50-0.65		yard (flat surface of artificially compacted ground)
						0.40-0.45		road
						0.4		rock (limestone)	1.2 m3 block size
						0.4		fine angular debris and earth, compacted (gravel and cobbles, dia < 20cm)
						0.60-0.70		fine angular debris and earth, soft
						0.50-0.60		medium angular debris with angular rock fragments (20-40cm)
						0.70-1.00		medium angular debris with scattered trees
						0.60-0.80		coarse angular debris with angular rock fragments (40-120 cm dia)
						0.45-0.50		earth with grass and some vegetation
						0.85		ditch with mud
						0.50-0.65		yard (flat surface of artificially compacted ground)
						0.40-0.45		road
						0.97	0.184	rock/thin debris	based on site tests	Strozza, Italy (1)	Azzoni, A., et al. "In situ observation of rockfall analysis parameters". Proceedings of the VI International Symposium on Landslides, Christchurch. February 10-14, 1992.
						0.75	0.159	fine debris		Strozza, Italy (2)
						0.39	0.117	debris and earth		Cagliari
						0.88	0.24	coarse debris		Val Malenco
						1.31	0.163	rock		Luserna
						0.84	0.301	coarse debris		Iselle
		0.1						clear quartz	friction coefficients for three conditions of surface moisture: oven-dried	N. Carolina	Horn, H.M., and Deere, D.U. (1962) "Frictional Characteristics of Minerals". Geotechnique. 12(4)319-335.
		0.14						milky quartz		Wisconsin
		0.11						rose quartz		Unknown
		0.11						microcline feldspar - A		Unknown
		0.12						microcline feldspar - B		Unknown
		-						Calcite (scratching)		N. Jersey
		-						Calcite (N.S.)		N. Jersey
		0.14						Calcite (N.S.)		Kansas
		0.43						Muscovite		Penna.
		0.41						Muscovite		Brazil
		0.45						Muscovite		Unknown
		0.31						Phlogopite		Madagascar
		0.3						Phlogopite		Canada
		0.31						Biotite		Canada
		0.53						Chlorite		Vermont
		0.62						Serpentine		Vermont
		0.76						Serpentine		Unknown
		0.38						Steatite		North Carolina
		0.36						Talc		Vermont
		0.1						clear quartz	friction coefficients for three conditions of surface moisture: oven-dried air equilibrated	N. Carolina
		0.16						milky quartz		Wisconsin
		0.11						rose quartz		Unknown
		0.11						microcline feldspar - A		Unknown
		0.12						microcline feldspar - B		Unknown
		0.21						Calcite (scratching)		N. Jersey
		0.12						Calcite (N.S.)		N. Jersey
		0.14						Calcite (N.S.)		Kansas
		0.3						Muscovite		Penna.
		0.32						Muscovite		Brazil
		0.36						Muscovite		Unknown
		0.25						Phlogopite		Madagascar
		0.22						Phlogopite		Canada
		0.26						Biotite		Canada
		0.35						Chlorite		Vermont
		0.47						Serpentine		Vermont
		0.65						Serpentine		Unknown
		0.26						Steatite		North Carolina
		0.24						Talc		Vermont
		0.23						clear quartz	friction coefficients for three conditions of surface moisture: saturated	N. Carolina
		0.27						milky quartz		Wisconsin
		0.26						rose quartz		Unknown
		0.76						microcline feldspar - A		Unknown
		0.77						microcline feldspar - B		Unknown
		0.6						Calcite (scratching)		N. Jersey
		-						Calcite (N.S.)		N. Jersey
		0.68						Calcite (N.S.)		Kansas
		0.23						Muscovite		Penna.
		0.22						Muscovite		Brazil
		0.26						Muscovite		Unknown
		0.15						Phlogopite		Madagascar
		0.16						Phlogopite		Canada
		0.13						Biotite		Canada
		0.22						Chlorite		Vermont
		0.26						Serpentine		Vermont
		0.48						Serpentine		Unknown
		0.19						Steatite		North Carolina
		0.16						Talc		Vermont
		0.74						slate	frictional coefficient at the displacement of 1.8 mm	Unknown	Onaka, M. (1975) "Frictional Characteristics of Typical Rocks". J. Phys. Earth. 23:87-112.
		0.76						Tuff		Unknown
		0.78						Trachyte		Mizuho
		0.87						Andesite		Manazuru
		0.76						Granite		Inada
		0.68						Monzonite		Orikabe
		0.53						Serpentinite		unknown
		0.44
		0.31						dolomite		Dunham
		0.36
		0.42						Limestone		Solenhofen
		0.38
		0.35						Marble		Yamaguchi
		0.44
		0.576	0.13					Rock	based on in-situ tests		Chau, K.T., Wong, R.H.C, and Lee, C.F. (1998) "Rock fall problems in Hong Kong and some new experimental results for coefficients of restitution". International Journal of Rock Mechanics and Mining Science. 35(4/5):662-663.
		0.562	0.0867					Soil
		0.559	0.118					Shotcrete
		0.557	0.054					Rock/soil