Swedish circle

(1)

CIE3032 지반공학및실험 lecture 04 slope stability 31

Swedish circle

Used for homogeneous clay soil with  = 0

Applicable only for short-term analysis of clay slopes (Undrained) Calculated from moment

∑ = ∑ _{1 1} _{2 2}

∑

Have to find center of circle /

failure surface that results in

lowest FS by trial and error

(2)

Swedish circle

Stability number (안정정수)

Fellenius (1927) Taylor (1937)

c d

 H

 c d

 H

 Stability factor (안정계수)

Terzaghi and Peck (1967)

한계상태에서의 비배수전단강도와 단위중량 – 사면고의 관계

(3)

Swedish circle

Used for homogeneous clay soil with  = 0

Applicable only for short-term analysis of clay slopes (Undrained) Calculated from moment equilibrium ∑ ∑

∑ = ∑ _{1 1} _{2 2}

∑

Have to find center of circle /

failure surface that results in

lowest FS by trial and error

(4)

Swedish circle

∑

FS = , Stability number

(안정정수)

Fellenius (1927) Taylor (1937)

c d

 H

 c d

 H

 Stability factor (안정계수)

Terzaghi and Peck (1967)

한계상태에서의 비배수전단강도와 단위중량 – 사면고의 관계

(Note at failure, c _d = s _u )

(5)

Swedish circle

(6)

Swedish circle

(7)

(8)

Swedish circle

(9)

Swedish circle

(10)

Ordinary method of slices

(11)

(12)

(13)

(14)

(15)

(16)

(17)

(18)

(19)

CIE3032 지반공학및실험 lecture 04 slope stability

49

(20)

(21)

3. Simplified Bishop’s method

(22)

(23)

cos _i _i W    P U

Simplified Bishop Method

(24)

(25)

(26)

(27)

(28)

(29)

(30)

(31)

Effect of water table

(32)

Swedish circle

Swedish circle

Used for homogeneous clay soil with  = 0

Applicable only for short-term analysis of clay slopes (Undrained) Calculated from moment

∑ = ∑ 1 1 2 2

∑

∑

∑

Have to find center of circle /

failure surface that results in

lowest FS by trial and error

Swedish circle

Stability number (안정정수)

Fellenius (1927) Taylor (1937)

c d

 H

 c d

 H

 Stability factor (안정계수)

Terzaghi and Peck (1967)

한계상태에서의 비배수전단강도와 단위중량 – 사면고의 관계

Swedish circle

Used for homogeneous clay soil with  = 0

Applicable only for short-term analysis of clay slopes (Undrained) Calculated from moment equilibrium ∑ ∑

∑ = ∑ 1 1 2 2

∑

∑

∑

Have to find center of circle /

failure surface that results in

lowest FS by trial and error

Swedish circle

∑

∑

FS = , Stability number

(안정정수)

Fellenius (1927) Taylor (1937)

c d

 H

 c d

 H

 Stability factor (안정계수)

Terzaghi and Peck (1967)

한계상태에서의 비배수전단강도와 단위중량 – 사면고의 관계

(Note at failure, c d = s u )

Swedish circle

Swedish circle

Swedish circle

Swedish circle

Ordinary method of slices

49

3. Simplified Bishop’s method

cos i i W    P U

Simplified Bishop Method

Effect of water table

Comparison of slope stability methods

Method

Force-equilibrium Moment Equilibrium

x y

Ordinary method of slices(OMS) Bishop’s simplified

Janbu’s simplified Corps of Engineers Lowe & Karafiath Janbu’s generalized Bishop’s rigorous Spencer’s

Sama ’s

Morgenstern-Price

No Yes Yes Yes Yes Yes Yes Yes Yes Yes

No No Yes Yes Yes Yes Yes Yes Yes Yes

Yes Yes

No

No

No

No

Yes

Yes

Yes

Yes

Swedish circle - Example

∑ = ∑ _{1 1} _{2 2}

∑ = ∑ _{1 1} _{2 2}

(Note at failure, c _d = s _u )

cos _i _i W    P U