Some Useful Numbers

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Some Useful Numbers on the Engineering Properties of Materials (Geologic and Otherwise)GEOL 615

Coefficient of sliding friction ()

For most rocks, varies between 0.8 and 0.5. A value of 0.60 would be a good number for general use.

Glass on glass0.4

Rubber on concrete0.75

Steel on steel0.55

Angle of internal friction (Rock30(Sand30-40(Gravel35(Silt34(Clay20(Loose sand30-35(

Medium sand40(

Dense sand35-45(

Gravel with some sand34-48(

Silt26-35(Because the angle of internal friction, , is typically around 25-35(, the coefficient of internal friction (tan is 0.5 to 0.7Cohesive strength (0)

Rock10,000 kPaSilt75 kPaClay10-20 kPaVery soft clay 0- 48 kPaSoft clay 48-96 kPaMedium clay96-192 kPaStiff clay192-384 kPaVery stiff clay384-766 kPaHard clay >766 kPaDensity (Sandy soil1800 kg/m3Gravel soil2000 kg/m3Silty soil2100 kg/m3

Clay soil1900 kg/m3

Mafic igneous rocks3000 kg/m3 Felsic igneous rocks2700 kg/m3Metamorphic rocks2700 kg/m3Sedimentary rocks2600 kg/m3

Granite2700 kg/m3Shale2500 kg/m3Limestone2700 kg/m3Chalk2100 kg/m3Sandstone2000 kg/m3Steel8000 kg/m3

Concrete1680-3000 kg/m3 Water1000 kg/m3

Unit weight () (recall that g)

Rock26.5 km3Gravel soil19 km3Sandy soil16 km3Silty soil20 km3Clay soil18 km3Water9.8km3Concrete23 km3

Steel78 km3Porosity

Gravel30-40%

Sand20-35 %

Silt35-50 %Clay33-60 %Sand and gravel, mixed20-35 %Glacial till10-20 %

Sandstone5-30%

Limestone5-30%

Shale 10-30 %Fractured igneous rock10-40%

Granite0.5-1.5 %Diabase 0.1-0.5 %Gabbro 0.1-0.2 %Basalt 0.1-1.0 %Gneiss 0.5-1.5 %Marble 0.5-2 %Slate 0.1-0.5 %Quartzite 0.1-0.5 %Permeability

Well-sorted gravel10-2 to 1 cm/secWell-sorted sands, glacial outwash10-3 to 10-1 cm/secSilty sands, fine sands10-5 to 10-3 cm/secSilt, sandy silts, clayey sands, till10-6 to 10-4 cm/secClay10-9 to 10-6 cm/secSoil Sensitivity

Insensitive clays 16

Compressibility (Cc)

Soft clay>0.3

Clay

0.3-0.15

Silty clay0.15-0.075

Sandy clay 400 kPaWood

10 MPaConcrete

2 MPaSteel

230 MPaTensile strength

Granite7-25 MPaBasalt10-30 MPa

Gneiss5-20 MPaQuartzite10-30 MPaSandstone4-25 MPaShale2-10 MPaLimestone5-25 MPaMarble

15 MPa

Steel

400 MPa

High strength steel750 MPa

Cast iron

170 MPa

Aluminum

450 MPa

Concrete

5 MPa

Rubber

15 MPa

P-wave velocity

Soil100-500 m/secGlacier ice3000-4000 m/secClay (dry)200-1400 m/secClay (wet)1200-2200 m/secAlluvium3000-5000 m/secWater1450-1500 m/secSand400-2300 m/secOil1300 m/secAir320-340 m/secGranite3000-5900 m/secBasalt4500-6500 m/secQuartzite5000-6500 m/secSandstone1400-4000 m/secShale1400-3000 m/secLimestone2500-6000 m/secMarble3500-6000 m/secSalt4500 m/sec

S-wave velocity

Clay (dry)410 m/secClay (saturated)390 m/secAlluvium1900 m/secWater0 m/sec (because no shear strength)Oil0 m/sec (because no shear strength)Air0 m/sec (because no shear strength)Limestone3100 m/secSandstone2400 m/secDolomite3000 m/sec

Shale2600 m/secGranite3400-3600 m/secDolerite3500-3600 m/secSalt2700 m/sec

Resistivity

Marble5 x 107-109 Ohm-mMica1011-1014 Ohm-mQuartz1012-1014 Ohm-mSlate1-2 x 106 Ohm-mPetroleum2 x1014 Ohm-mDistilled water5000 Ohm-mSaltwater 2 ppm3.4 Ohm-mSaltwater 10 ppm0.72 Ohm-mSaltwater 20 ppm0.38 Ohm-mSaltwater 100 ppm0.09 Ohm-m

----- (Unfractured) ----