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Input values

N 5

ER 60SPT Correction factors

Cs 1

Cr 1

Cb 1

Ce 1

N60 5

D/B 0.5

effective unit weight (kN/m^3) 9.23

Foundation Width (m) 0.6 1 1.5 2 3.048

Depth of interest (m) 0.6 1 1.5 2 3.048

Vertical effective stress (kPa) 5.538 9.23 13.845 18.46 28.133Liao&Witman depth correction factor 0.2353 0.3038 0.3721 0.4297 0.5304

N1,60 10.00 10.00 10.00 10.00 9.43

TERZAGHI BEARING CAPACITY EQUATION FOR SANDS

 Applied Factor of Safety 3.00

Using Hatanaka & Uchida (1996), Mayne (2001) equation

Friction angle (degrees) 32.4 32.4 32.4 32.4 32.0

Ngamma (Chen) 40.4 40.4 40.4 40.4 38.1

Ngamma (Brinch-Hansen) 22.2 22.2 22.2 22.2 21.0

Nq (same for all) 24.3 24.3 24.3 24.3 23.3

Ultimate capacity (kPa) 128.9 214.8 322.1 429.5 622.6

 Allowable stress (kPa) 43.0 71.6 107.4 143.2 207.5Using De Mello (1971), Schmertmann (1975) and Mayne (2001) equation

Friction angle (degrees) 35.6 35.1 34.5 34.0 32.9

Ngamma (Chen) (not used) 68.2 62.7 56.9 52.1 44.0

Ngamma (Brinch-Hansen) 37.6 34.6 31.4 28.7 24.2

Nq (same for all) 36.0 33.8 31.4 29.4 25.9

Ultimate capacity (kPa) 203.9 315.7 435.0 536.1 705.3

 Allowable stress (kPa) 68.0 105.2 145.0 178.7 235.1

Using Empirical Meyerhof (1956) equation for bearing capacity

Ultimate capacity (kPa) 73.8 123.0 184.6 246.1 375.0

 Allowable stress (kPa) 24.6 41.0 61.5 82.0 125.0

DEFORMATION CRITERIONUsing Burland & Burbridge (1984) Approach

 Allowable settlement (mm) 25.4

Inducing mean-σ stress (KPa) 111.3 77.9 58.6 47.9 35.7

Inducing mean stress (kPa) 202.6 141.7 106.7 87.2 65.0

Inducing mean+σ stress (KPa) 368.7 257.9 194.1 158.7 118.2

page 2 of 2

DETERMINISTIC SHALLOW FOUNDATION DESIGN USING SPT DATA

developed by Dimitris P. Zeccos, available by the Geoengineer Website

Version 1.0

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Notes:

The values in the yellow boxes are those that the user can change.Corrections for the blowcount according to Youd et al (2001)

References:

Schmertmann, J.H. (1975), Measurement of insitu shear strength , keynote lecture, Proceedings of the

conference on in-situ measurement of soil properties, June 1-4, 1975, vol. II, American Society of Civil

Engineers.

Burland, J.B., Burbidge, M.C. (1984), Settlement of foundations on sand and gravel , Proceedings of the

Institution of Civil Engineers, Part 1, 1985, 78, Dec., 1325-1381.

Mayne, P.W. (2001), Geotechnical site characterization using Cone, piezocone, SPTu, and VST , Civil and

Environmental Engineering Department, Georgia Institute of Technology

Methods developed according to correlations provided in the references. No responsibility is

assumed for the results of the spreadsheet.

Hatanaka, M., Uchida, A. (1996). Empirical correlation between penetration resistance and effective friction of 

sandy soil . Soils & Foundations, Vol. 36 (4), 1-9, Japanese Geotechnical Society.

Meyerhof, G.G. (1956), Penetration tests and bearing capacity of cohesionless soils , Journal of the soil

mechanics and foundation division, ASCE, Vol. 82, No. SM1, January, pp. 1-19.

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

0 0.5 1 1.5 2 2.5 3 3.5

   A   l   l  o  w  a   b   l  e  s   t  r  e  s  s ,

   k   P  a

Foundation width, m

Allowable Stress

Bearing Hatanaka Bearing Schmertman

Meyerhoff Burland mean stress

Burland mean-σ stress Burland mean+σ stress

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