Transmission And Substation Foundations - Technical Design Manual

SECTION 4: DESIGN METHODOLOGY

Factor of Safety

Reported Correlations between SPT N 60 Value and Unit Side Resistance [Lutenegger (2011)], Table 4-11 Pile Type Soil β α Reference

Granular

0

2.0

Meyerhof (1976)

Miscellaneous soils (f s < 170 kPa)

10

3.3

Decourt (1982)

Cohesive

0

10

Shioi & Fukui (1982)

Cohesive

0

3

Driven displacement

Bazaraa & Kurkur (1986)

Cohesionless

0

1.8

Sandy

29

2.0

Kanai & Yubuuchi (1989)

Clayey

34

4.0

Miscellaneous

0

1.9

Robert (1997)

Granular

0

1.0

Meyerhof (1976)

Granular

55

5.8

Fujita et al. (1977)

Cohesionless

0

3.3

Wright & Reese (1979)

Cohesive (fs < 170 kpa)

10

3.3

Decourt (1982)

Cohesive

0

5.0

Shioi & Fukui (1982)

Cohesive

0

1.8

Bazaraa & Kurkur (1986)

Cohesionless

0

0.6

Residual soil & weathered rock

0

2.0

Broms et al. (1988)

Clay

0

1.3

Koike et al. (1988)

Sand

0

0.3

Sandy soil

35

3.9

Kanai & Yubuuchi (1989)

Cohesive

24

4.9

Bored

Residual soil

0

4.5

Winter et al. (1989)

Gravel

0

6.0

Sand

0

4.0

Hirayama (1990)

Silt

0

2.5

Clay

0

1.0

Residual soils

0

2.0

Chang & Broms (1991)

Clayey soil

0

10.0

Matsui (1993)

Sandy soil

0

3.0

Miscellaneous

17.3 18.2

1.18 0.65

Vrymoed (1994)

Miscellaneous

0

1.9

Robert (1997)

Sand

0

5.05

Kuwabara & Tanaka (1998)

Weathered rock

0

4

Wada (2003)

Cohesionless

0

5.0

Shoi & Fukui (1982)

Cohesive

0

10.0

Cast-in-place

Cohesionless (F s < 200 kPa)

30

2.0

Yamashita et al. (1987)

Cohesive (F s < 150 kPa)

0

5.0

Note: f s = β + αN 60 (f s in units of kPa)

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