S.N.

Methods

Factor of Safety

Probability of Failure (%)

Reliability Index

Deterministic

Probabilistic

1.

Ordinary/Fellenius

0.835

0.842

98.30

2.358

2.

Bishop Simplified

0.887

0.893

92.70

1.52

3

Janbu Simplified

0.828

0.834

98.90

2.476

4.

Janbu Corrected

0.872

0.879

95.00

1.714

5.

Spencer

0.879

0.889

93.50

1.575

6.

GLE/Morgenstern-Price

0.880

0.889

94.10

1.573

7.

Corps of Engineers#1

0.886

0.894

92.10

1.492

8.

Corps of Engineers#2

0.889

0.897

91.40

1.45