CMT Laboratories, Inc.2701 Carolean Industrial Drive

State College, PA 16801Phone: 814-231-8845

Fax: 814-231-8846

Terzaghi's Bearing Capacity General Shear Failure w/ Water Table (Case II)

B

Df

dWT

Input Parametersc 100psf:= Cohesion

B 5ft:= Width of Footing

γ 120pcf:= Unit Weight

γsat 130pcf:= Saturated Unit Weight

γw 62.4pcf:= Unit Weight of Water

γ' γsat γw−:= γ' 67.6 pcf⋅= Effective Unit Weight

ϕ 30deg:= Angle of Internal Friction0 d≤ B≤

Df 3.5ft:= Depth of Footing

d 5ft:= See Diagram γ'' γ'dB

γ γ'−( )⋅+:= γ'' 120 pcf⋅= Average Unit Weight

FS 3:= Factor of Safety

q γ'' Df⋅( ) Df Df d+( )< Df B+( )<if

γ Df⋅( ) otherwise

:=

q 420 psf⋅= Surcharge

Bearing Capacity Factors

Nqe2 0.75 π⋅

ϕ

2⎛⎜⎝

⎞⎟⎠

−⎡⎢⎣

⎤⎥⎦

⋅ tan ϕ( )⋅⎡⎢⎣

⎤⎥⎦

2 cos 45degϕ

2+⎛⎜

⎝⎞⎟⎠

⎛⎜⎝

⎞⎟⎠

2⋅

⎡⎢⎣

⎤⎥⎦

⎡⎢⎢⎢⎢⎣

⎤⎥⎥⎥⎥⎦

:= Nq 22.456= Surcharge Contribution

Nc cot ϕ( ) Nq 1−( )⋅:= Nc 37.16= Cohesion Contribution

Nγ Nq 1−( ) tan 1.4 ϕ⋅( )⋅:= Nγ 19.32= Meyerhof (1963) Unit Weight Contribution

Bearing Capacity - Wall Footing

quw c Nc⋅ q Nq⋅+ 0.5 γ''⋅ B⋅ Nγ⋅+:= quw 18943 psf⋅= Ultimate

qnawquw q−( )

FS:=

qnaw 6174 psf⋅= Net Allowable

Client:Project:CMT File No.

1 2/20/2013Designed by:______Checked by:______

CMT Laboratories, Inc.2701 Carolean Industrial Drive

State College, PA 16801Phone: 814-231-8845

Fax: 814-231-8846

Terzaghi's Bearing Capacity General Shear Failure w/ Water Table (Case II)

(Cont'd)Bearing Capacity - Square Footing

qus 1.3c Nc⋅ q Nq⋅+ 0.4 γ''⋅ B⋅ Nγ⋅+:= qus 18899 psf⋅= Ultimate

qnasqus q−( )

FS:=

qnas 6160 psf⋅= Net Allowable

Bearing Capacity - Circular Footing

quc 1.3c Nc⋅ q Nq⋅+ 0.3 γ''⋅ B⋅ Nγ⋅+:= quc 17740 psf⋅= Ultimate

qnacquc q−( )

FS:=

qnac 5773 psf⋅= Net Allowable

Client:Project:CMT File No.

2 2/20/2013Designed by:______Checked by:______