Soil mechanics

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Soil Mechanics (1) Fff


Soil Mechanics (1) Fff


Chapter (1)

Physical properties

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2011

Soil Mechanics for Second Year Civil Engineering Course Content: Δϴ΋Ύϳΰϴϔϟ΍ ι΍ϮΨϟ΍

Chapter (1): Physical Properties. Chapter (2): Grain Size Distributions.

ΕΎΒϴΒΤϠϟ ϰϤΠΤϟ΍ ϊϳίϮΘϟ΍ ΔΑήΘϟ΍ ϡ΍Ϯϗ

Chapter (3): Soil Consistency.

ΔΑήΘϟ΍ ϒϴϨμΗ

Chapter (4): Soil Classification.

ΔΑήΘϟ΍ ϚϣΩ

Chapter (5): Soil Compaction. Chapter (6): Hydraulic Properties of the Soil.

ΔΑήΘϠϟ ΔϴϜϴϟϭέΪϴϬϟ΍ ι΍ϮΨϟ΍ Chapter (7): Stress Due to Applied Load. ΔϴΟέΎΨϟ΍ ϝΎϤΣϷ΍ Ϧϣ ΞΗΎϨϟ΍ ΩΎϬΟϹ΍ Chapter (8): Consolidation.

Soil Mechanics (1)

ΪϠμΘϟ΍


Chapter (1)

Physical properties

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2011

Chapter (1) Physical Properties ΔΑήΘϠϟ Δϴ΋Ύϳΰϴϔϟ΍ ι΍ϮΨϟ΍ -: Ϧϣ ΎϬϟ ϲόϴΒτϟ΍ ϊοϮϟ΍ ϲϓ ΔΑήΘϟ΍ ϥϮϜΘΗ - Particles

ΕΎΒϴΒΣ ˯Ύϣ

- water

˯΍Ϯϫ

- Air Solid

Va

Wa = 0

Vw

Ww

Vv Void Vt Water

Air

Ws

Vs

Natural state

Prism

Vt = ΔΑήΘϠϟ ϰϠϜϟ΍ ϢΠΤϟ΍

Ws = ΐϠμϟ΍ ˯ΰΠϟ΍ ϥίϭ

Vv = ΕΎϏ΍ήϔϟ΍ ϢΠΣ

Ww = ˯ΎϤϟ΍ ϥίϭ

Vs = ΐϠμϟ΍ ˯ΰΠϟ΍ ϢΠΣ

Wa = zero = ˯΍ϮϬϟ΍ ϥίϭ

Vw = ˯ΎϤϟ΍ ϢΠΣ

Wt = ϰϠϜϟ΍ ϥίϮϟ΍

Va = ˯΍ϮϬϟ΍ ϢΠΣ

Soil Mechanics (1)

Wt


Chapter (1)

Physical properties

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2011

Physical Properties ΕΎϏ΍ήϔϟ΍ ΔΒδϧ

1) Void ratio: (e)

e

Vv

Vv Vs

Vs

ΔΑήΘϠϟ ΐϠμϟ΍ ˯ΰΠϟ΍ ϢΠΣ ϰϟ· ΕΎϏ΍ήϔϟ΍ ϢΠΣ ϦϴΑ ΔΒδϨϟ΍ ϲϫ

e 0.5 0.8 o Sand e 0.7 1.1 o Clay

ΔϴϣΎδϤϟ΍

2) Porosity: (n)

n

Vv

Vv Vt

Vt

ΔΑήΘϠϟ ϰϠϜϟ΍ ϢΠΤϟ΍ ϰϟ· ΕΎϏ΍ήϔϟ΍ ϢΠΣ ϦϴΑ ΔΒδϨϟ΍ ϲϫ

n

0.0 1.0 ϊΒθΘϟ΍ ΔΟέΩ

3) Degree of saturation: (Sr)

Sr

Vw Vv

Vv

Vw

ΔΑήΘϟ΍ ϲϓ ΓΩϮΟϮϤϟ΍ ΕΎϏ΍ήϔϟ΍ ϢΠΣ ϰϟ· ˯ΎϤϟ΍ ϢΠΣ ϦϴΑ ΔΒδϨϟ΍ ϲϫ

Soil Mechanics (1)


Chapter (1)

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Sr = 0.0

Sr = 100

Dry ΔϓΎΟ

Saturated

4) Water content : ( Wc )

Wc

Physical properties

Sr = 0- 100

ΔόΒθϣ

ΔϠϠΒϣ

Wet

ϲ΋ΎϤϟ΍ ϯϮΘΤϤϟ΍

Ww Ws

Ww Ws

ΔΑήΘϠϟ ΐϠμϟ΍ ˯ΰΠϟ΍ ϥίϭ ϰϟ· ˯ΎϤϟ΍ ϥίϭ ϦϴΑ ΔΒδϨϟ΍ ϲϫ

ΔϓΎΜϜϟ΍ 5) Unit weight (density): (J) W ϥίϮϟ΍ J ϢΠΤϟ΍ V ϢΠΤϟ΍ ϰϟ· ϥίϮϟ΍ ϦϴΑ ΔΒδϨϟ΍ ϲϫ

Jb

Jd

Js

Jsat.

Jsub.

˯ΎϤϟ΍ ΔϓΎΜϛ ϥ΃ φΣϻ Jw = 1 t/m3 = 1 g/cm3 = 10 kN/m3 3 3 = 62.4 Ib/ft = 1000 kg/m Soil Mechanics (1) P


Chapter (1)

Physical properties

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a) Bulk density: (Jb)

J

b

ΔϴϠϜϟ΍ ΔϓΎΜϜϟ΍

Wt Vt

ΔΑήΘϠϟ ϰϠϜϟ΍ ϢΠΤϟ΍ ϰϟ· ϰϠϜϟ΍ ϥίϮϟ΍ ϦϴΑ ΔΒδϨϟ΍ ϲϫ

˯ΎϤγϷ΍ Ϧϣ ήϴΜϜϟ΍ ΎϬϟ ϭ Bulk = natural = total = wet = moist b) Dry density: (Jd)

J

ΔϓΎΠϟ΍ ΔϓΎΜϜϟ΍

Ws Vt

d

ΔΑήΘϠϟ ϰϠϜϟ΍ ϢΠΤϟ΍ ϰϟ· ΐϠμϟ΍ ˯ΰΠϟ΍ ϥίϭ ϦϴΑ ΔΒδϨϟ΍ ϲϫ

c) Density of solid part: (Js)

J

s

ΐϠμϟ΍ ˯ΰΠϟ΍ ΔϓΎΜϛ

Ws Vs

ΔΑήΘϠϟ ΐϠμϟ΍ ˯ΰΠϟ΍ ϢΠΣ ϰϟ· ΐϠμϟ΍ ˯ΰΠϟ΍ ϥίϭ ϦϴΑ ΔΒδϨϟ΍ ϲϫ

Soil Mechanics (1)


Chapter (1)

Physical properties

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2011

ΔόΒθϤϟ΍ ΔϓΎΜϜϟ΍

d) Saturated density: (Jsat.)

J

Wt Vt

sat

ΔΑήΘϟ΍ ϊΒθΗ ΔϟΎΣ ϲϓ ϰϠϜϟ΍ ϢΠΤϟ΍ ϰϟ· ϰϠϜϟ΍ ϥίϮϟ΍ ϦϴΑ ΔΒδϨϟ΍ ϲϫ

ΓέϮϤϐϤϟ΍ ΔϓΎΜϜϟ΍

e) Submerged density: (Jsub.)

J sub. J sat. J w ( Ϯ˰ϔ˰τϟ΍ ΔΠϴΘϧ ) ˯ΎϤϟ΍ ΔϓΎΜϛ ΎϬϨϣ Ρϭήτϣ ΔόΒθϤϟ΍ ΔϓΎΜϜϟ΍ ϲϫ

6) Specific gravity: (Gs)

Gs

ϲϋϮϨϟ΍ ϥίϮϟ΍

Js Jw

˯ΎϤϟ΍ ΔϓΎΜϛ ϰϟ· ΐϠμϟ΍ ˯ΰΠϟ΍ ΔϓΎΜϛ ϦϴΑ ΔΒδϨϟ΍ ϲϫ

( 2.6 - 2.8 ϦϴΑ ΎϬΘϤϴϗ Ρϭ΍ήΘΗϭ

Soil Mechanics (1)


Chapter (1)

Physical properties

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2011

7) Relative density: (Dr)

Dr

emax eo emax emim

ΔϴΒδϨϟ΍ ΔϓΎΜϜϟ΍

Vmax Vo Vmax Vmim

ςϘϓ sand ΔϴϠϣήϟ΍ ΔΑήΘϟ΍ ϒϴϨμΘϟ ϡΪΨΘδΗ emim. = dense state (ΎϬπόΑ Ϧϣ ΍ΪΟ ΔΒϳήϗ ΕΎΒϴΒΤϟ΍ ϥϮϜΗ) ΔϔϴΜϜϟ΍ ΔϟΎΤϟ΍ = compacted state emax. = loose state (ΎϬπόΑ Ϧϣ ΍ΪΟ ΓΪϴόΑ ΕΎΒϴΒΤϟ΍ ϥϮϜΗ) ΔϜϜϔϤϟ΍ ΔϟΎΤϟ΍ eo = natural state (ΔόϴΒτϟ΍ ϲϓ ϲϫ ΎϤϛ ΕΎΒϴΒΤϟ΍ ϥϮϜΗ) ΔϴόϴΒτϟ΍ ΔϟΎΤϟ΍ = in-situ state = field state Vmax = loose state

ΔϜϜϔϤϟ΍ ΔϟΎΤϟ΍ ϰϓ ϢΠΤϟ΍

Vmim = dense state

ΔϔϴΜϜϟ΍ ΔϟΎΤϟ΍ ϰϓ ϢΠΤϟ΍

Vo = natural state

ΔϴόϴΒτϟ΍ ΔϟΎΤϟ΍ ϰϓ ϢΠΤϟ΍

Soil Very loose Loose Medium Dense Very dense

Dr (%) 0 - 15 15 - 35 35 - 65 65 - 85 85 - 100

Soil Mechanics (1)


Chapter (1)

Physical properties

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2011

φΣϝ

1

J

Dr

J

mim

1

J

1

mim

o

1

J

max

n (1) Â&#x; e 1 n e ( 2) Â&#x; n 1 e (3) Â&#x; sr * e Gs * Wc ( 4) Â&#x; J d (5) Â&#x; J b

φϔΣ

φϔΣ

ΎϏΗΎΒΛ· Î?ĎŽĎ Ď„ĎŁ όϴϧÎ?ĎŽĎ˜Ď&#x;Î? ΞĎŒÎ‘ ϙΎϨύ

Jb 1 Wc Gs sr * e ( ) *J w 1 e

Soil Mechanics (1)


Chapter (1)

Physical properties

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2011

ϢΠΤĎ&#x;Î? Ď­ ĎĽÎŻĎŽĎ&#x;Î? όϴΑ Î”Ď—ĎźĎŒĎ&#x;Î?

φϔΣ

Vw

w

Ww

Vs

s

Ws

Ws Gs * J w *Vs Ww J w *Vw ΕΎ˰ΗΎ˰Β˰ΛϚÎ?

Prove that

Jb

§ Gs sr * e ¡ ¨ ¸ *J w Š 1 e š OR

Find the relation between

Jb, Gs, Sr, e, Jw Soil Mechanics (1)

φϔΣ

ÎŽĎ´Ď?Î˜Ďł Ďť ΖΑΎΛ Î?Ď ÎźĎ&#x;Î? ˯ΰΠĎ&#x;Î?

ÎŽĎ´Ď?Î˜Ďł Ďť ΖΑΎΛ Î?Ď ÎźĎ&#x;Î? ˯ΰΠĎ&#x;Î?

a


Chapter (1)

Physical properties

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2011

ΕΎΒΛϹ΍ Ε΍ϮτΧ ( ϢϬϓάΣ ) ϢϬΑ ΃ΪΒϧ ϻ ( J or Gs ) Ϫϴϓ ϥϮϧΎϘϟ΍ ϥΎϛ ΍Ϋ· -˺ ϢϬϴϓ ΪΣ΍ϭ ϱ΄Α ΃ΪΒϧ ( Sr, e ) ϰϘΒΗ -˻

e

Vv Vs 1= ϡΎϘϤϟ΍ νήϔϧ Assume

(Vs = 1)

VV = e Prism ϲϓ νϮόϧ -˼

e Sr*e 1

Sr*e*Jw Gs*Jw

Vw Vw Sr Vv e Vw Sr * e Soil Mechanics (1)


Chapter (1)

Physical properties

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2011

( Jb ) ϪΑ ÎƒÎŞÎ’ϧ Ďť ϹΏĎ&#x;Î? ϲĎ“ νώĎŒϧ -Ë˝

Wt Vt Sr * e * J w Gs * J w 1 e ( Sr * e Gs ) * J w 1 e

Jb Jb Jb Prove that

Jb

Jd

1 Wc OR

Find the relation between

Jb, Jd, Wc ΕΎΒΛϚÎ? ΕÎ?ĎŽĎ„Χ ( ϢϏĎ“ÎŹÎŁ ) ϢϏΑ ÎƒÎŞÎ’ϧ Ďť ( J or Gs ) ĎŞĎ´Ď“ ϼώϧÎŽĎ˜Ď&#x;Î? ĎĽÎŽĎ› Î?΍· -Ëş ΎϏΑ ÎƒÎŞÎ’ϧ (Wc ) Ď°Ď˜Î’Î— -Ëť

Wc

Ww Ws

Soil Mechanics (1)


Chapter (1)

Physical properties

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2011

1= ĎĄÎŽĎ˜ϤĎ&#x;Î? νΎĎ”ϧ Assume (Ws = 1) Wc = Ww Prism ϲĎ“ νώĎŒϧ -Ëź

Wc Jw 1 Gs

Wc 1

(Jd , Jb ) ϪΑ ÎƒÎŞÎ’ϧ Ďť ϹΏĎ&#x;Î? ϲĎ“ νώĎŒϧ -Ë˝

Jb Jd

J J J

d b

1 Wc Vt

Wt Vt 1 Vt

(2)

1 1 Wc

J d

(1)

b

1 Wc

Soil Mechanics (1)


Chapter (1)

Physical properties

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2011

Prove that

Sr * e Gs *Wc OR

Find the relation between

Sr, e, Gs, Wc ΕΎΒΛϹ΍ Ε΍ϮτΧ ( ϢϬϓάΣ ) ϢϬΑ ΃ΪΒϧ ϻ ( J or Gs ) Ϫϴϓ ϥϮϧΎϘϟ΍ ϥΎϛ ΍Ϋ· -˺ ΎϬΑ ΃ΪΒϧ (Wc, Sr, e ) ϰϘΒΗ -˻

Vv Vs

e

1= ϡΎϘϤϟ΍ νήϔϧ Assume (Vs = 1) e = Vv Prism ϲϓ νϮόϧ -˼

e

1

Sr e

Sr e Jw Gs Jw

Soil Mechanics (1)


Chapter (1)

Physical properties

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2011

(Wc, Gs) ϪΑ ÎƒÎŞÎ’ϧ Ďť ϹΏĎ&#x;Î? ϲĎ“ νώĎŒϧ -Ë˝ ĎŞĎ´Ď“ ΞϳώĎŒÎ˜Ď&#x;Î? ϢÎ˜Ďł Ďť ΖΑΎΛ

Gs

Ww Sr * e * J w Ws Gs * J w Sr * e Gs

Wc Wc Prove that

e n 1 e OR

Find the relation between

e, n ΕΎΒΛϚÎ? ΕÎ?ĎŽĎ„Χ ( ϢϏĎ“ÎŹÎŁ ) ϢϏΑ ÎƒÎŞÎ’ϧ Ďť ( J or Gs ) ĎŞĎ´Ď“ ϼώϧÎŽĎ˜Ď&#x;Î? ĎĽÎŽĎ› Î?΍· -Ëş ϢϏϨϣ Ϲ΄Α ÎƒÎŞÎ’ϧ (n, e ) Ď°Ď˜Î’Î— -Ëť

e

Vv Vs

Assume (Vs = 1) e = Vv

Soil Mechanics (1)


Chapter (1)

Physical properties

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Prism ϲĎ“ νώĎŒϧ -Ëź

e

1

(n) ϪΑ ÎƒÎŞÎ’ϧ Ďť ϹΏĎ&#x;Î? ϲĎ“ νώĎŒϧ -Ë˝

vv vt

n

e 1 e

Prove that

n e 1 n OR

Find the relation between

e, n ΕΎΒΛϚÎ? ΕÎ?ĎŽĎ„Χ ( ϢϏĎ“ÎŹÎŁ ) ϢϏΑ ÎƒÎŞÎ’ϧ Ďť ( J or Gs ) ĎŞĎ´Ď“ ϼώϧÎŽĎ˜Ď&#x;Î? ĎĽÎŽĎ› Î?΍· -Ëş

Soil Mechanics (1)


Chapter (1)

Physical properties

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2011

ϢϏϨϣ Ϲ΄Α ÎƒÎŞÎ’ϧ (n, e ) Ď°Ď˜Î’Î— -Ëť

n

Vv Vt

Assume (Vt = 1) n = Vv Prism ϲĎ“ νώĎŒϧ -Ëź

n 1 1-n

(e) ϪΑ ÎƒÎŞÎ’ϧ Ďť ϹΏĎ&#x;Î? ϲĎ“ νώĎŒϧ -Ë˝

vv vs

e

n 1 n

Try: Prove that

Jb

Gs * J w (1 Wc) (1 e) Soil Mechanics (1)


Chapter (1)

Physical properties

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2011

Prove that

(J s J d )J w (J s * J d )

Wc( sat.) OR

Find the relation between

Wc, Js Jd Jw ΕΎΒΛϚÎ? ΕÎ?ĎŽĎ„Χ ϢϏϨϣ Ϲ΄Α ÎƒÎŞÎ’ϧ ( Js Jd Jw) ΔĎ&#x;ϝΪΑ ĎŞĎ Ď› ϼώϧÎŽĎ˜Ď&#x;Î? -Ëş

Js

Ws Vs

Assume (Vs = 1) Js = Ws ĎŠÎ’θΘĎ&#x;Î? ΔĎ&#x;ÎŽÎŁ Ď°Ď“ ĎŚĎœĎ&#x; Ď­ Prism ϲĎ“ νώĎŒϧ -Ëť

Js Jd

Js 1 Jd

w

1

S

¡ §Js ¨¨ 1 ¸¸J w š ŠJd

Js

Soil Mechanics (1)


Chapter (1)

Physical properties

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2011

Jd

Ws Vt

Vt

Js Jd

Js Vt

(Wc) ϲĎ“ νώĎŒϧ -Ëź

§Js ¡ ¨¨ 1 ¸¸ J w ŠJd š

Ww Ws

Wc

Js

J s

J d J w Jd *J s

Wc

Prove that

Sr

Wc Wc ( sat .) OR

Find the relation between

Sr, Wc Wc(sat) ΕΎΒΛϚÎ? ΕÎ?ĎŽĎ„Χ ( Wc ) ˰Α ÎƒÎŞÎ’ϧ -Ëş

Soil Mechanics (1)


Chapter (1)

Physical properties

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2011

Ww Ws

Wc

Assume (Ws = 1) ˱Wc = Ww

Ww Ws

Wc( sat )

˱Wc = Ww (sat.) (ϊΒθϣ ήΧϷ΍ϭ ˯΍Ϯϫ ϲϓ ΪΣ΍ϭ ) ϦϴΗήϣ Prism Ϣγήϧ -˻ a Wc

Jw

VV =

w

Wc

S

Wc( sat )

Jw

(Wc / J w ) (Wc( sat ) / J w )

Sr

Vw Vv

Sr

Wc Wc ( sat ) Soil Mechanics (1)

w

Wc(sat)

S


Chapter (1)

Physical properties

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2011

( ήΟΎΤϤϟ΍ Δϟ΄δϣ ϲϓ ) φΣϻ

(1)

(2)

Pit ήΠΤϣ

Embankment ϲΑ΍ήΗ Ϊγ

e1

e2

V1

V2

Jd2 J d1

1 e1 1 e2

V1 V2

Ϟ΋ΎδϤϟ΍ ω΍Ϯϧ΃ Ϧϴόϣ ϢΠΣ ϭ΃ ϥίϭ ΔϤϴϗ ΎϬΑ ΔϟΎδϣ

Ϧϴόϣ ϢΠΣ ϭ΃ ϥίϭ ΔϤϴϗ ΎϬϴϓ ΪΟϮϳ ϻ ΔϟΎδϣ

prism ˰ϟ΍ Ϣγέ ϢΘϳ ΔϟΎδϣ ϯ΍ Δϳ΍ΪΑ ϲϓ

prism ˰ϟ΍ Ϣγέ ϢΘϳ ΔϟΎδϣ ϯ΍ Δϳ΍ΪΑ ϲϓ

a

a

w

w

S

S Assume

ΕΎϴτόϤϟ΍ ϡ΍ΪΨΘγΎΑ prism ˰ϟ΍ ˯΍ΰΟ΃ ϸϤϧ

Vs = 1

ϡ΍ΪΨΘγ΍ ϊϣ

Soil Mechanics (1)


Soil Mechanics (1) Fff


Chapter (1)

Physical properties

1

2011

όϴϧÎ?ĎŽĎ˜Ď&#x;Î? ÎşÎ¨Ď ĎŁ

1) Â&#x; e 3) Â&#x; Sr

Vv Vs Vw Vv

Vv Vt

2) Â&#x; n 4 ) Â&#x; Wc

5) Â&#x; J b

Wt Vt

6) Â&#x; J

7) Â&#x; J s

Ws Vs

8 ) Â&#x; J sat

9) Â&#x; J sub. J sat. J w 11 ) Â&#x; Dr

d

10 ) Â&#x; Gs

e max e o e max e mim

Ww Ws

Ws Vt Wt Vt

Js Jw

ΎϏΗΎΒΛ· Î?ĎŽĎ Ď„ĎŁ όϴϧÎ?ĎŽĎ˜Ď&#x;Î? ΞĎŒÎ‘ ϙΎϨύ

e n 13) Â&#x; n 12) Â&#x; e 1 e 1 n Jb 14) Â&#x; sr * e Gs * Wc 15) Â&#x; J d 1 Wc Gs sr * e ) *J w 16) Â&#x; J b ( 1 e

Soil Mechanics (1)


Chapter (1)

Physical properties

2

2011

ϢΠΤĎ&#x;Î? Ď­ ĎĽÎŻĎŽĎ&#x;Î? όϴΑ Î”Ď—ĎźĎŒĎ&#x;Î?

Ws

Gs * J w * Vs

Ww

J w * Vw

( ÎŽÎ&#x;ÎŽΤϤĎ&#x;Î? ΔĎ&#x;΄δϣ ϲĎ“ ) φΣϝ

(1)

(2)

Pit ΎΠΤϣ

Embankment ϲΑÎ?ΎΗ ÎŞÎł

e1

e2

V1

V2

V1 V2

1 e1 1 e2

Soil Mechanics (1)

Jd2 J d1


Chapter (1)

Physical properties

3

2011

Example (1) The bulk density of soil sample is 1.97 gm/cm3 and its water content 20 % taking the specific gravity 2.65, find the void ratio and degree of saturation. Solution Given

Jw

Jb = 1.97 gm/cm3

1 .0

Wc = 20 % Gs = 2.65

a

1.61

0.53

w

0.53

1

S

2.65

Assume Vs = 1 Ws = Gs * 1 * Jw = 2.65

Soil Mechanics (1)


Chapter (1)

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2011

Physical properties

Ww Wc Ws Ww 0.2 Â&#x; Ww 0.53 2.65 Ww J w * Vw Vw 1.0

Wt Jb Vt 2.65 0.53 1.97 Â&#x; Vt 1.61 Vt Vv 1.61 1 e 0.61 Vs 1 Vw 0.53 Sr 0.86 86% Vv 1.61 1 Example (2) The bulk and dry densities of soil sample are 1.77 and 1.5 t/m3 respectively, if the degree of saturation is 60 % what is the specific gravity and porosity. Then calculate the quantity of water added for full saturation without change of volume.

Soil Mechanics (1)


Chapter (1)

Physical properties

5

2011

Solution Given Jb = 1.77 t/m3 Jd = 1.5 t/m3 Sr = 60 %

a

0.66Gs

0.18Gs

w

0.18Gs

1

S

Gs

Assume Vs = 1

Ws

Gs * J w

Ws Jd Vt GS 1 .5 Â&#x; Vt Vt

Gs

0 .66 Gs

Soil Mechanics (1)


Chapter (1)

Physical properties

6

2011

Wt Vt

Jb 1 . 77

Wt Wt 0 . 66 Gs

1 . 18 Gs

Vw Sr Vv 0 . 18 Gs 0 .6 Gs 0 . 66 Gs 1

2 . 72 a

1.82

n

Vv Vt

Full saturated

1.82 1 1.82

0.49

w

0.49

1

S

2.72

0.82

w

0.82

1

S

2.72

0.45

45%

1.82

Weight of water = 0.82 - 0.49 = 0.33 ton Per unit volume of solid part

Soil Mechanics (1)


Chapter (1)

Physical properties

7

2011

Example (3) An earth embankment is to be compacted to a dry density of 1.84 t/m3, the bulk density and water content of a borrow pit are 1.77 t/m3 and 8 % respectively, calculate the volume of excavation of borrow pit which corresponds to 1 m3 of embankment. Solution Given

Embankment Jd = 1.84 t/m

ΎΠΤϣ Borrow pit Jb = 1.77 t/m3

3

Wc = 8 %

V2 = 1 m3

Jd Jd

V1 V2

J d2 J d1

V1 1

1 . 84 Â&#x; V 1 ( pit ) 1 . 64

Jb

V1 = ???

1 Wc 1.77 1 0.08

1 . 12 m 3

Soil Mechanics (1)

1.64


Chapter (1)

Physical properties

8

2011

Example (4) The weight of a partially soil sample is 600 gm and its volume is 365 cm3 after oven drying the weight of the sample reduced to 543 gm. Taking the specific gravity 2.67, find the water content, void ratio and degree of saturation. If the sample is saturated with water without change of volume, find the saturated density. Solution Given Wt = 600 gm Vt = 365 cm3 W dry = Ws = 543 Gs = 2.67 a

365

57

w

57 600

203.4

S

543

Soil Mechanics (1)


Chapter (1)

Physical properties

9

2011

Ws

Gs * J w *Vs

543 2.67 *1*Vs Vs 203.4 Ww J w *Vw Vw 57 Ww 57 0.105 10.5% Ws 543 Vv 365 203.4 e 0.795 Vs 203.4 Vw 57 Sr 0.353 35.3% Vv 365 203.4

Wc

ήϴϐΘϳ ϻ ΖΑΎΛ ΐϠμϟ΍ ˯ΰΠϟ΍ 161.6

Full saturated

w

161.6 704.6

365 203.4

J sat .

Wt Vt

704 . 6 365

S

1 . 93 t / m 3

Soil Mechanics (1)

543


Chapter (1)

Physical properties

10

2011

Example (5) (mid term 2010) A saturated 100 cm3 clay sample has a natural water content of 15 % . If the specific gravity of the soil solids is 2.7, what will be the volume of the sample when the water content is 25 %.

Solution Given: Case (1)

Case (2)

Vt = 100 cm3

Vt = ???

Wc = 15 %

Wc = 25 %

Gs = 2.7

Jw = 1 g/cm3

Case (1) Vs + Vw = 100

(1)

Ww 0.15 Ws Ww 0.15 * Ws WC

w

Vw

Vs

S

2.7Vs

100

Vw 0.15 * 2.7 * Vs Vw 0.405 * Vs (2) From (1), (2)

Vw

Vw = 28.83

,

Ww = 28.83 ,

Vs = 71.17 Ws = 192.16

Soil Mechanics (1)


Chapter (1)

Physical properties

11

2011

Case (2) WC

Ww Ws

0.25

Vw

w

Vw

71.17

S

192.16

ˮˮˮ

Ww 0.25 * Ws Ww 0.25 *192.16 Ww 48.04 Vw 48.04

Vt

71.17 48.04 119.21

Soil Mechanics (1)


Chapter (1) 2011

12

Soil Mechanics (1)

Physical properties


Soil Mechanics (1) Fff


Zagazig University Faculty of Engineering

Structural Eng. Department Ëş

Soil Mechanics (1)

Sheet (1) Physical Properties 1) A sample of soil obtained from a test pit is one cubic centimeter in volume and weight 140 gm, after oven drying the sample weight 125 gm. calculate the water content, moist unit weight, dry unit weight. 2) A 150 cubic centimeter sample of wet soil scales 250 gm when saturated and 162 gm when oven dried. Calculate the dry unit weight, water content, void ratio, specific gravity. 3) Laboratory test on sample of saturated soil show that the void ratio is 0.45 and the specific gravity is 2.65. Determine the wet unit weight of the soil and its water content 4) The moisture content of an undisturbed sample of clay existing in a volcanic region is 265 % at 100 % of saturation. The specific gravity is 2.7. Find the saturated and submerged densities. 5) For a soil in natural state, given e = 0.70, Wc = 22 % and Gs = 2.69 a) Determine the moist unit weight, dry unit weight and degree of saturation. b) If the soil is made completely saturated by adding water, what would its moisture content be at that time? Also find the saturated unit weight. 6) Determine the wet density, dry density, void ratio, water content and degree of saturation for a sample of moist soil which has a mass of 18.18 Kg and occupies a total volume of 0.009 m3. When dried in an oven, the dry mass is 16.13 Kg. the specific gravity is 2.70.


Zagazig University Faculty of Engineering

Structural Eng. Department Ëť

Soil Mechanics (1)

7) An undisturbed cylindrical soil sample, with diameter 8.0 cm, and height of 25.0 cm is taken from the borehole. The moist sample has a mass of 2371.0 gm and after drying in an oven has a dry mass of 1948.0 gm. The specific gravity of the solid particles is 2.72. Determine water content, bulk, dry, saturated and submerged unit weight of soil, void ratio, porosity and degree of saturation. 8) A cylinder contains 500 cm3 of loose dry sand which weight 750 gm and under load of 20 t/m2, the original volume decreased by 3 % and then by vibration the volume decreased by 10 %, assume the solid density of sand grains is 2.65 t/m3. compute the void ratio, porosity, dry density corresponding to each of the following cases: a) Loose sand (original state) b) Under static load c) Loaded and vibrated 9) A clayey soil has natural moisture content of 15.18 %. The specific gravity of soil is 2.72. Its saturation percentage is 70.81 %. The soil is allowed to absorb water. After some time the saturation increase to 90.8 %. Find out the water content of the soil in the latter case. 10) A saturated 100 cm3 clay sample has a natural water content of 15 % . If the specific gravity of the soil solids is 2.7, what will be the volume of the sample when the water content is 25 %. 11) A sample of moist quartz sand was obtained by carefully pressing a sharpened cylinder with a volume of 150 cm3 into the bottom of an excavation. The sample was trimmed flush with the end of the cylinder and the total weight was found to be 325 gm. In the laboratory the dry weight of the sand alone was found to be 240 gm and the weight of the empty cylinder 75 gm. Laboratory testes on the dry sand indicated emax = 0.80 and emim = 0.48. (Assuming Gs = 2.66). Calculate: Wc, e, Sr. Jd, and Dr


Chapter (1)

Physical properties

(1)

2011

Solution 1) A sample of soil obtained from a test pit is one cubic foot in volume and weight 140 gm, after oven drying the sample weight 125 gm. calculate the water content, moist unit weight, dry unit weight.

Given: Vt = 1 ft3

,

Wt = 140 gm

Wdry = Ws = 125 gm

Req. Wc , Jd , Jb

a 1 ft3

w

15 140

S

125

Soil Mechanics (1)


Chapter (1) 2011

Wc

Jb Jd

Physical properties

(2)

Ww 15 0 . 12 12 % Ws 125 Wt 140 140 gm / ft 3 Wt 1 Ws 125 125 gm / ft 3 Vt 1

2) A 150 cubic centimeter sample of wet soil scales 250 gm when saturated and 162 gm when oven dried. Calculate the dry unit weight, water content, void ratio, specific gravity.

Given: Vt = 150 cm3

,

Wt = 250 gm

Wdry = Ws = 162 gm

,

Req. Jd , Wc , e , Gs

Soil Mechanics (1)

saturation


Chapter (1)

Physical properties

(3)

2011

88

w

88

150

250 62

S

162

Ws 162 1 . 08 gm / cm 3 Jd 150 Vt 88 Ww 0 . 54 54 % Wc 162 Ws Vv 88 1 . 42 e 62 Vs J s 162 / 62 2 . 61 Gs Jw 1

Soil Mechanics (1)


Chapter (1)

Physical properties

(4)

2011

3) Laboratory test on sample of saturated soil show that the void ratio is 0.45 and the specific gravity is 2.65. Determine the wet unit weight of the soil and its water content

Given: e = 0.45

,

Gs = 2.65

,

saturation

Req. Jb , Wc

0.45

w

0.45

1.45

3.1 1

S

2.65

Assume Vs = 1.0

Soil Mechanics (1)


Chapter (1)

(5)

2011

Physical properties

Vv Vv 0 . 45 Â&#x; Vv Vw Vs 1 Wt 3 .1 2 . 14 gm / cm 3 Jb Vt 1 . 45 Ww 0 . 45 Wc 0 . 17 17 % Ws 2 . 65 e

0 . 45

4) The moisture content of an undisturbed sample of clay existing in a volcanic region is 265 % at 100 % of saturation. The specific gravity is 2.7. Find the saturated and submerged densities.

Given: Wc = 265 % , Gs = 2.7 , saturation

Req. Jsat. , Jsub.

Assume Vs = 1.0

Soil Mechanics (1)


Chapter (1)

Physical properties

(6)

2011

7.15

w

7.15

8.15

9.85 1

Wc

J sat . J sub .

S

2.7

Ww Ww 2 .65 Â&#x; Ww 7 .15 Ws 2 .7 Wt 9 .85 1.21t / m 3 Vt 8 .15 J sat . J w 1.21 1 0.21t / m 3

5) For a soil in natural state, given e = 0.70, Wc = 22 % and Gs =2.69. a) Determine the moist unit weight, dry unit weight and degree of saturation. b) If the soil is made completely saturated by adding water, what would its moisture content be at that time? Also find the saturated unit weight.

Soil Mechanics (1)


Chapter (1)

Physical properties

(7)

2011

Given: e = 0.7 , wc = 22 %, Gs = 2.69 Req. a) Jb Jd Sr b) Wc Jsat saturated state

a 0.7

w

0.59

0.59

8.15 9.85 S

1

Wc

e

0.22

Ww Ws

Vv Â&#x; 0 .7 Vs

2.69

Ww Â&#x; Ww 2.69

Vv Â&#x; Vv 1 .0

Soil Mechanics (1)

0 .7

0 .59


Chapter (1) 2011

Jb Jd

Physical properties

(8)

Wt Vt Ws Vt

2.69 0 .59 1 .93 1 .7 2.69 1 .59 1 .7

Vw Vv

0 .59 0 .7

Sr

0 .85

Saturated state

0.7

w

0.7

1.7 1

Wc

J sat .

Ww Ws Wt Vt

S

2.69

0 .7 0 . 26 2 . 69 2 . 69 0 . 7 1 . 99 t / m 3 1 .7 Soil Mechanics (1)


Chapter (1)

Physical properties

(9)

2011

6) Determine the wet density, dry density, void ratio, water content and degree of saturation for a sample of moist soil which has a mass of 18.18 Kg and occupies a total volume of 0.009 m3. When dried in an oven, the dry mass is 16.13 Kg. the specific gravity is 2.70.

Sol.

w

5.9*10-3

0.009

2.05*10-3

3.1*10-3

a

Jb

Wt Vt

18 .18 0 .009

2.05 18.18

S

16.13

2020 kg / m 3

Ϧϴϧ΍ϮϘϟ΍ ϰϓ ϖϴΒτΘϟ΍ ϢΘϳ ΍άϜϫ ϭ

Soil Mechanics (1)


Chapter (1)

Physical properties

(10)

2011

7) An undisturbed cylindrical soil sample, with diameter 8.0 cm, and height of 25.0 cm is taken from the borehole. The moist sample has a mass of 2371.0 gm and after drying in an oven has a dry mass of 1948.0 gm. The specific gravity of the solid particles is 2.72. Determine water content, bulk, dry, saturated and submerged unit weight of soil, void ratio, porosity and degree of saturation. Sol.

V

4

S 4

8 cm

(d ) 2 * h (8 ) 2 * 25

8 cm

V

S

1256 cm 3

a 540

423

w

423

1256 2371 716

S

1948

Soil Mechanics (1)


Chapter (1)

Physical properties

(11)

2011

ϊΒθΘϟ΍ ΔϟΎΣ ϰϓ

540

w

540

1256 716

S

1948

Ϧϴϧ΍ϮϘϟ΍ ϰϓ ϖϴΒτΘϟ΍ ϦϜϤϳ

Ϟ΋ΎδϤϟ΍ ϲϗΎΑ

H.W.

Soil Mechanics (1)


Soil Mechanics (1) Fff


Chapter (2)

Grain Size Distribution

1

2011

Chapter (2) Grain Size Distribution ΕΎΒϴΒΤϠϟ ϰϤΠΤϟ΍ ϊϳίϮΘϟ΍ ϰϠϋ Ϟμϔϟ΍ ΔϘϳήσ ΪϤΘόΗ ϭ ϢΠΤϟ΍ ΐδΣ ΔΑήΘϟ΍ ΕΎϧϮϜϣ Ϟμϓ Ϯϫ ΔΑήΘϟ΍ ωϮϧ

Coarse soil ΔϨθΧ ΔΑήΗ

Fine soil ΔϤϋΎϧ ΔΑήΗ

Sand , gravel

Silt , clay

Ϧϣ ήΒϛ΍ ΕΎΒϴΒΤϟ΍ ϢΠΣ

Ϧϣ ήϐλ΍ ΕΎΒϴΒΤϟ΍ ϢΠΣ

0.074 mm

0.074 mm

ΔϨθΨϟ΍ ΔΑήΘϟ΍ Ϟμϔϟ

ΔϤϋΎϨϟ΍ ΔΑήΘϟ΍ Ϟμϔϟ

Sieve analysis = Dry analysis = Mechanical analysis

Hydrometer analysis = Wet analysis = Sedimentation analysis

Soil Mechanics (1)


Chapter (2)

Grain Size Distribution

2

2011

1) Sieve analysis

ϞΧΎϨϤϟΎΑ ϞϴϠΤΘϟ΍ -:ίΎϬΠϟ΍

ϞΨϨϤϟ΍ ΔΤΘϓ ϞϘϳ

W1 W2 W3 W4 W5 W6

ί΍ΰϫ

-:ΔΑήΠΘϟ΍ Ε΍ϮτΧ ΔϳϮΌϣ ΔΟέΩ ˺˺˹ ΪϨϋ ΔϋΎγ ˻˽ ΓΪϤϟ ϥήϔϟ΍ ϲϓ ΔΑήΘϟ΍ ϒϴϔΠΗ ϢΘϳ -˺ ΎϬϧίϭ ΔϔϔΠϤϟ΍ ΔΑήΘϟ΍ Ϧϣ ΔϨϴϋ άΧ΍ ϢΘϳ -˻ ςϟΰϟ΍ ΔϟΎΣ ϲϓ ϢΠϛ (˺˹-˾) Ϟϣήϟ΍ ΔϟΎΣ ϲϓ ϢΠϛ (˺-˹̄˾)

Soil Mechanics (1)


Chapter (2)

Grain Size Distribution

3

2011

ϞΧΎϨϤϟ΍ ϰϠϋ΃ ΔϨϴόϟ΍ ϊοϭ -˼ ΔϘϴϗΩ ˺˾ ΓΪϤϟ ί΍ΰϬϟ΍ ϞϴϐθΗ -˽ ϞΨϨϣ Ϟϛ ϰϠϋ (ϊΟ΍ήϟ΍)ίϮΠΤϤϟ΍ ϥίϮϟ΍ ΪϳΪΤΗ ϢΘϳ -˾ ΕΎΑΎδΤϟ΍ ξόΑ ϞϤϋ ϭ ϝϭΪΟ ϦϳϮϜΘΑ ϡϮϘϧ -˿ ( grading curve) ϲΒϴΒΤϟ΍ ΝέΪΘϟ΍ ϰϨΤϨϣ Ϣγέ ϢΘϳ -̀

A Sieve size (mm)

Wt. retained ίϮΠΤϤϟ΍ ϥίϮϟ΍

50.8 38.1 19.05 9.52 4.76 2.38 2.0 1.19 0.595 0.42 0.297 0.21 0.14 0.074 0.063

W1 W2 W3 W4 W5 W6 W7

B = total

Commutative Wt. retained ϲϤϛ΍ήΘϟ΍

B

C

Wt. passing % passing έΎϤϟ΍ ϥίϮϟ΍

w1 w1+w2 W1+w2+w3

weight –A

C = (B / Total weight)*100

Soil Mechanics (1)


Chapter (2)

Grain Size Distribution

4

2011

(grading curve ) ϲΒϴΒΤϟ΍ ΝέΪΘϟ΍ ϰϨΤϨϣ Ϣγέ :ϲϠϳ ΎϤϛ semi-log scale αΎϴϘϣ ϰϠϋ ϲΒϴΒΤϟ΍ ΝέΪΘϟ΍ ϰϨΤϨϣ Ϣγέ ϢΘϳ ( % passing ) ϲγ΃έ ήΧ΃ ϭ ( sieve size ) ϲϘϓ΃ έϮΤϣ Ϣγέ ϢΘϳ -˺ Ϣγ ˺ Ϟϛ ΔϳϭΎδΘϣ ΕΎϓΎδϣ ϰϟ· ϲγ΃ήϟ΍ έϮΤϤϟ΍ ϢϴδϘΗ -˻

% Passing

S = Ϣγ ˾-˼ Ϟϛ ΔϳϭΎδΘϣ ΕΎϓΎδϣ ϰϟ· ϲϘϓϷ΍ έϮΤϤϟ΍ ϢϴδϘΗ -˼

100 90 80 70 60 50 40 30 20 10 0

S = 3-5 cm

100

10

1 0.1 Seive Size

0.01

0.001

ΔϴγΎϴϗ ϞΧΎϨϣ ϦϛΎϣ΃ :ϲϠϳ ΎϤϛ ϲϘϓϷ΍ έϮΤϤϟ΍ ϰϠϋ ϞΧΎϨϤϟ΍ ϦϛΎϣ΃ ΪϳΪΤΗ -˽ ϞΨϨϤϟ΍ ΎϬϴϓ ϊϗ΍Ϯϟ΍ ΓήΘϔϟ΍ ΪϳΪΤΗ ήϴϐμϟ΍ ϞΨϨϤϟ΍ Ϧϣ x ΪόΑ ϰϠϋ ϞΨϨϤϟ΍ ϥΎϜϣ νήϔϧ -

X

S >log( D ) log( small ) @

ϪόϴϗϮΗ ΏϮϠτϤϟ΍ ϞΨϨϤϟ΍

Soil Mechanics (1)

-

Ϧϣ ήϴϐμϟ΍ ϞΨϨϤϟ΍


Chapter (2) 2011

Ex: sieve (26.7) X

1 ήϴϐμϟ΍ 10 3 . 0 >log( 4 . 75 ) log( 1) @

X

2 . 03 cm

0.01 ήϴϐμϟ΍ 0.1

Sieve (0.074) X

100 10 ήϴϐμϟ΍

3 . 0 >log( 26 . 7 ) log( 10 ) @ 1 . 3 cm

Sieve (4.75)

% Passing

Grain Size Distribution

5

3 . 0 >log( 0 . 074 ) log( 0 . 01 ) @

100 90 80 70 60 50 40 30 20 10 0

2 . 61 cm

XD10

D60

100

10

D30

1 0.1 Seive Size

D10

Soil Mechanics (1)

0.01

0.001


Chapter (2)

Grain Size Distribution

6

2011

ϰϠϋ ϝϮμΤϟ΍ ϦϜϤϳ ϰϨΤϨϤϟ΍ Ϧϣ

D 10

ΕΎΒϴΒΤϟ΍ Ϧϣ % ˺˹ ϩΪϨϋ ήϤϳ ϱάϟ΍ ήτϘϟ΍

D 30

ΕΎΒϴΒΤϟ΍ Ϧϣ % ˼˹ ϩΪϨϋ ήϤϳ ϱάϟ΍ ήτϘϟ΍

D 60

ΕΎΒϴΒΤϟ΍ Ϧϣ % ˿˹ ϩΪϨϋ ήϤϳ ϱάϟ΍ ήτϘϟ΍ D10

ΔϤϴϗ ϰϠϋ ϞμΤϧ ϒϴϛ

3 .0>log( D10 ) log( 0 .01) @

X D10

ήϴϐμϟ΍ ΔϬΟ Ϧϣ Ϣγήϟ΍ Ϧϣ ΓήτδϤϟΎΑ αΎϘΗ D30

ΔϤϴϗ ϰϠϋ ϞμΤϧ ϒϴϛ

3 .0>log( D30 ) log( 0 .1) @

X D30

ήϴϐμϟ΍ ΔϬΟ Ϧϣ Ϣγήϟ΍ Ϧϣ ΓήτδϤϟΎΑ αΎϘΗ D60

X D60

ΔϤϴϗ ϰϠϋ ϞμΤϧ ϒϴϛ

3 .0>log( D60 ) log(1) @

ήϴϐμϟ΍ ΔϬΟ Ϧϣ Ϣγήϟ΍ Ϧϣ ΓήτδϤϟΎΑ αΎϘΗ

ϲΒϴΒΤϟ΍ ΝέΪΘϟ΍ ϰϨΤϨϣ ϡ΍ΪΨΘγ΍

Uses of grading curve: 1) Uniform coefficient (Cu) Cu

D 60 D10

ϡΎψΘϧϻ΍ ϞϣΎόϣ

ΔΑήΘϟ΍ ϒϴϨμΗ ϲϓ ϡΪΨΘδϳ

Soil Mechanics (1)


Chapter (2)

Grain Size Distribution

7

2011

(B.S.) ϱΰϴϠΠϧϹ΍ ϡΎψϨϟ΍

(ASTM) ϲϜϳήϣϷ΍ ϡΎψϨϟ΍

Uniform Non-uniform Well

5

Poor

15

Cc

Poor

3) Effective diameter (D10)

(sand)

4

(gravel)

ΔΑήΘϟ΍ ϒϴϨμΗ ϲϓ ϡΪΨΘδϳ

Well

1

6

˯ΎϨΤϧϻ΍ ϞϣΎόϣ

2) Curvature coefficient (Cc) ( D 30 ) 2 D 60 * D10

Well

Poor

3

˯ΎϨΤϧϻ΍ ϞϣΎόϣ

ΪϳΪΤΗ ϲϓ ϡΪΨΘδϳϭ ΕΎΒϴΒΤϟ΍ Ϧϣ % ˺˹ ϩΪϨϋ ήϤϳ ϱάϟ΍ ήτϘϟ΍ Hazen's formula ϝϼΧ Ϧϣ ϚϟΫϭ ( K ) ΔϳΫΎϔϨϟ΍ ϞϣΎόϣ

K

C * ( D10 ) 2

C = Constant (1-10) C=1

ΔΑήΘϟ΍ ωϮϧ ϰϠϋ ΪϤΘόϳ

for sand

Soil Mechanics (1)


Chapter (2)

Grain Size Distribution

8

% passing

2011

2 4 1

3

Size ΎΒϳήϘΗ ΪΣ΍ϭ αΎϘϣ ΎϬΑ ΔϨϴόϟ΍

1) Uniform: 2) Non-uniform:

Ϟϛ ΎϬΑ βϴϟϭ ΓΩΪόΘϣ ΕΎγΎϘϣ ΎϬΑ ΔϨϴόϟ΍ ΔϳϭΎδΘϣ ήϴϏ ΐδϨΑ ΕΎγΎϘϤϟ΍ Ϟϛ ΎϬΑ ϭ΃ ΕΎγΎϘϤϟ΍

3) Well graded:

(΍ΪΟ Γήϴϐλ ΎϬΗΎϏ΍ήϓ) ΕΎγΎϘϤϟ΍ Ϟϛ ΎϬΑ ΔϨϴόϟ΍

4) Gap graded:

ΔμϗΎϧ ΕΎγΎϘϤϟ΍ ξόΑ ΎϬΑ ΔϨϴόϟ΍

Note: Poorly graded

Uniform Non-Uniform Gap graded

Soil Mechanics (1)


Chapter (2)

9

2011

1) Wet analysis (Hydrometer)

Grain Size Distribution

ήΘϣϭέΪϴϬϟ΍ -:ίΎϬΠϟ΍

Reading

Z

Bulb

Hydrometer

˼

Ϣγ˺˹˹˹ έΎΒΨϣ

-:ΔΑήΠΘϟ΍ Ε΍ϮτΧ ˯Ύϣ ϪΑ ˼ Ϣγ ˺˹˹˹ έΎΒΨϣ έΎπΣ· ϢΘϳ -˺ ϢΟ ˾˹ ΎϬϧίϭ ˻˹˹ Ϣϗέ ϞΨϨϤϟ΍ Ϧϣ ΓέΎϤϟ΍ ΔΑήΘϟ΍ Ϧϣ ΔϨϴϋ άΧ΍ ϢΘϳ -˻ ΙΪΤϳ ϥ΃ ϰϟ· ήϤΘδϤϟ΍ Νήϟ΍ ϊϣ έΎΒΨϤϟ΍ ϞΧ΍Ω ΔϨϴόϟ΍ ϊοϭ ϢΘϳ -˼ έΎΒΨϤϟ΍ ϞΧ΍Ω ΕΎΒϴΒΤϠϟ ϊϳίϮΗ ΔϴϨϣί ΓήΘϓ Ϟϛ Ε΍˯΍ήϗ άΧ΍ ϭ έΎΒΨϤϟ΍ ϲϓ ήΘϣϭέΪϴϬϟ΍ ϊοϭ ϢΘϳ -˽ ( 0.5,1,2,4,8,……..30 mim. , 1,2,4,8,…..24 hr ) ϲΒϴΒΤϟ΍ ΝέΪΘϟ΍ ϰϨΤϨϣ Ϣγέϭ ΕΎΑΎδΤϟ΍ ξόΑ ϞϤόΑ ϡϮϘϧ -˾

Soil Mechanics (1)


Chapter (2)

Grain Size Distribution

10

2011

Stock's law Ϟ΋Ύδϟ΍ ϞΧ΍Ω Δϳή΋΍Ϊϟ΍ ΔΒϴΒΤϟ΍ ρϮϘγ Δϋήγ ΔΒϴΒΤϟ΍ ήτϗ ϊΑήϣ ϊϣ ϱΩήσ ΐγΎϨΘΗ

V v D2

D

C * D2 Js Jw C 18 P

V

V

ΚϴΣ ΕΎΒϴΒΤϟ΍ Δϋήγ = V -˺ ΕΎΒϴΒΤϟ΍ ήτϗ = D -˻ ΔΒϠμϟ΍ ΕΎΒϴΒΤϟ΍ ΔϓΎΜϛ = Js -˼ Ϟ΋Ύδϟ΍ ΔΟϭΰϟ = P -˽

P ( poise ) 981

V

Z t

gm . sec . / cm 2

Js Jw * D2 D 18 P ΔΒϴΒΤϟ΍ ρϮϘγ ΔϓΎδϣ = Z ΔΒϴΒΤϟ΍ ρϮϘγ Ϧϣί = t

Soil Mechanics (1)


Chapter (2)

11

2011

Grain Size Distribution

( N ) έÎŽϤĎ&#x;Î? ΔΒδϧ Ď°Ď Ď‹ ĎžΟΤϧ Ď’Ď´Ď› At time zero

Wt Vt Ws Vt Ws Vt Ws Vt Ws Vt Ws Vt Ws Vt

Ji Ji Ji Ji Ji Ji Ji J initial

J ( time )

N

ΔΑΎΠΘĎ&#x;Î? ΔϳÎ?ΪΑ ϲĎ“

Ws Ww Vt Vw Ww Vt Vs J w * Vw Vt J w * (Vt Vs ) Vt Vs ) J w (1 Vt Ws ) J w (1 Vt * Gs * J w Ws Jw Vt * Gs 1 Ws Jw (1 )Â&#x; N Vt Gs

Ws 1 Jw N * * (1 ) Vt Gs

Wt . ˜ of ˜ particles D Ws

Soil Mechanics (1)

w

Ww

S

Ws

Ws = Gs Jw Vs Ww = Jw Vw

100 %


Chapter (2)

Grain Size Distribution

12

2011

ϥ΃ ΚϴΣ Ws = ΔϨϴόϟ΍ ϥίϭ % passing

Vt = (˼Ϣγ˺˹˹˹) έΎΒΨϤϟ΍ ϢΠΣ

Sieve analysis

Hydrometer analysis

Size No. 200 = 0.074 mm

What the meaning of Cu = 1.0

Cu

D60 D60 D10

D10

ϲΒϴΒΤϟ΍ ΝέΪΘϟ΍ ϰϨΤϨϣ ϥ΃ ϚϟΫ ϰϨόϳ ΔΑήΘϟ΍ ϥϮϜΗ ϲϟΎΘϟΎΑϭ ΎϣΎϤΗ ϲγ΃έ ϥϮϜϳ very uniform soil

Soil Mechanics (1)

ϲΒϴΒΤϟ΍ ΝέΪΘϟ΍ ϰϨΤϨϣ


Soil Mechanics (1) Fff


Zagazig University

Structural Eng. Department Ëş

Faculty of Engineering

Soil Mechanics (1)

Sheet No. (2) Grain Size Distribution 1- a) discuss the difference between the following: i) Dry analysis and wet analysis. ii) Well Graded and poorly graded. b) Draw the grain size distribution curve for two soils A and B where the total weight of the sample is 500 gm for each soil. Calculate, i) uniformity coefficient of each soil and comment on the results, ii) effective diameter of each sample. Sieve opening, mm 4.78 2.41 1.20 0.6 0.3 0.15 0.075 pan Wt. retained (A), gm ---- 72 91 75 182 15 55 10 Wt. retained (B), gm ---- ---4 8 201 52 227 8

2- A sieve analysis performed on two soils produced the following data. Particle size, mm % finer (A) % finer (B)

18.8 9.4 4.75 2.0 0.42 0.25 0.15 0.075 0.05 0.005 0.002 92

84

70

65

52

44

30

24

20

11

8

---

---

---

100

98

95

90

82

72

41

21

Mix the two soils in such proportions that resulting mixture which will contain 26 % of 0.005 mm clay. Draw the grading curve for the mixture and classify it. 3- Proof the general equation used to determine the drain size distribution for fine soil particles by means of Hydrometer. 4- A soil sample consisting of particles of size 0.50 mm to 0.08 mm is put on the surface of still water of a tank 5 m deep. Determine the time


Zagazig University Faculty of Engineering

Structural Eng. Department Ëť

Soil Mechanics (1)

required for the settlement of the coarsest and the finest particles of the sample to the bottom of the tank. Take Gs = 2.68 and P = 0.01 poise. 5- During a sedimentation test for grain size analysis, the corrected hydrometer reading in a 1000 ml uniform soil suspension at the commencement of sedimentation is 1.028. after 30 minutes, the corrected hydrometer reading is 1.012 and the corresponding effective depth is 10.5 cm, determine: i) The total mass of solid dispersed in 1000 ml of suspension. ii) The particle size corresponding to the 30 minutes reading. iii) The percentage finer than this size, take Gs = 2.67 and P = 0.01 poise. 6- Particles of 5 different sizes are mixed in the proportions shown below and enough water is added to make 1000 ml of the suspension. The temperature of the suspension is 20o C. Particle size (mm) 0.05 0.02 0.01 0.005 0.001 Weight (gm) 7 20 18 4 5 If it is insured that the suspension is mixed so as have a uniform distribution of particles. All particles have a specific gravity of 2.7, assume Jw = 1 gm/cm3, t = 20o C, P 0.01 poise. i) What is the largest particles size present at a depth of 6 cm after minutes of start sedimentation? ii)What is the specific gravity of the suspension at a depth of 6 cm after 5 minutes of start of sedimentation. iii)How long should be the sedimentation be allowed so that all the particles have settled below 6 cm.


Chapter (2)

Grain Size Distribution

(1)

2011

Sheet No. (2) Grain Size Distribution 1) a) discuss the difference between the following: i) Dry analysis and wet analysis. Dry analysis wet analysis Soil Course soil Fine soil Size > 0.075 mm <0.075 mm Tools sieves Hydrometer Example Sand, gravel Silt, clay ii)

Well graded and poorly graded. Well graded

Poorly graded

ΐδϨΑ ΕΎγΎϘϤϟ΍ Ϟϛ ΎϬΑ ΔϨϴόϟ΍ ΔϳϭΎδΘϣ

1) Uniform ΎΒϳήϘΗ ΪΣ΍ϭ αΎϘϣ ΎϬΑ ΔϨϴόϟ΍ 2) Non-uniform Ϟϛ ΎϬΑ βϴϟϭ ΓΩΪόΘϣ ΕΎγΎϘϣ ΎϬΑ ΔϨϴόϟ΍ ΕΎγΎϘϤϟ΍ 3) Gap graded ΔμϗΎϧ ΕΎγΎϘϤϟ΍ ξόΑ ΎϬΑ ΔϨϴόϟ΍

Well

Cc 1

3

Poor

Poor

1

Soil Mechanics (1)

3

Cc


Chapter (2)

(2)

2011

Grain Size Distribution

b) Draw the grain size distribution curve for two soils A and B where the total weight of the sample is 500 gm for each soil. Calculate, i) uniformity coefficient of each soil and comment on the results, ii) effective diameter of each sample. Sieve opening, mm 4.78 2.41 1.20 0.6 0.3 0.15 0.075 pan Wt. retained (A),gm ---- 72 91 75 182 15 55 10 Wt. retained (B),gm ---- ---- 4 8 201 52 227 8

Sol. For Soil (A) sieve open 4.78 2.41 1.2 0.6 0.3 0.15 0.075 pan

Wt. retained of (A) ------72 91 75 182 15 55 10

commulative Wt. Ret. -----72 163 238 420 435 490 500

Soil Mechanics (1)

Passing % Wt. passing -----100 428 85.6 337 67.4 262 52.4 80 16 65 13 10 2 0 0


Chapter (2)

Grain Size Distribution

(3)

2011

For Soil (B) Wt. retained of Commulative Passing % (B) sieve open Wt. Ret. Wt. passing 4.78 ----------------100 2.41 --------------100 1.2 4 4 496 99.2 0.6 8 12 488 97.6 0.3 201 213 287 57.4 0.15 52 265 235 47 0.075 227 492 8 1.6 pan 8 500 0 0 100 90

Soil A

80

Soil B

% Passing

70 60 50 40 30 20 10 0 10

1

0.1 sieve open

Soil Mechanics (1)

0.01


Chapter (2)

Grain Size Distribution

(4)

2011

For Soil (A) D60 = 0.85 D10 = 0.15

Cu

D60 D10

0.85 0.15

5.67

(B.S.) ϱΰϴϠΠϧϹ΍ ϡΎψϨϟ΍

(ASTM) ϲϜϳήϣϷ΍ ϡΎψϨϟ΍

Uniform Non-uniform Well

5 5.67

Poor

5.67 6

15

Soil is Non-uniform

Well

(sand)

Soil is Poor

For Soil (B) D60 = 0.31 D10 = 0.085

Cu

D60 D10

0.31 3.65 0.085

Soil is uniform

OR

Soil is Poor

Soil Mechanics (1)


Chapter (2)

Grain Size Distribution

(5)

2011

2)A sieve analysis performed on two soils produced the following data. Particle 26.7 18.8 9.4 4.75 2.0 0.42 0.25 0.15 0.075 0.05 0.005 0.002 size, mm % finer 100 92 84 70 65 52 44 30 24 20 11 8 (A) % finer ----- --- --- 100 98 95 90 82 72 41 21 (B)

Mix the two soils in such proportions that resulting mixture which will contain 26 % of 0.005 mm clay. Draw the grading curve for the mixture and classify it.

+

=

X

+

1-X

=

0.11

0.41

Mix˶

1 0.26

X * 0.11 + (1-X) * 0.41 = 1* 0.26 X = 0.5 ,

(1-X) = 0.5 ϥϮϜϳ ϦϜϟ ϭ mix ˰ϟ΍ ϝϭΪΟ ϦϳϮϜΗ ϢΘϳ

Mix. = 0.5 * A + 0.5 * B Soil Mechanics (1)


Chapter (2)

Grain Size Distribution

(6)

2011

size, mm 26.7 18.8 9.4 4.75

2.0

0.42 0.25 0.15 0.075 0.05 0.005 0.002

% (A)

100

92

84

70

65

52

44

30

24

20

11

8

% (B)

---

---

---

---

100

98

95

90

82

72

41

21

Mix.

100

96

92

85

82.5

75

69.5

60

53

46

26

14.5

100 90

B

70 % Passing

A

Mix.

80

60 50 40 30 20 10 0 100

10

1

0.1

0.01

0.001

sieve open

3)Proof the general equation used to determine the drain size distribution for fine soil particles by means of Hydrometer.

Ρήθϟ΍ Γήϛάϣ ϲϓ ΕΎΒΛϹ΍

Soil Mechanics (1)


Chapter (2)

Grain Size Distribution

(7)

2011

4) A soil sample consisting of particles of size 0.50 mm to 0.08 mm is put on the surface of still water of a tank 5 m deep. Determine the time required for the settlement of the coarsest and the finest particles of the sample to the bottom of the tank. Take Gs = 2.68 and P = 0.01 poise. Sol.

:φΣϝ ϲύ όϴϧÎ?ĎŽĎ— Î™ĎźÎœÎ‘ ÎŽĎŹĎ ÎŁ ϢÎ˜Ďł Ϟ΋ΎδϤĎ&#x;Î? ĎŚĎŁ ωώϨĎ&#x;Î? Î?ÎŹĎŤ

C * D2 J s J w Â&#x;Â&#x; C 18P Z Â&#x;Â&#x; V t

1) Â&#x; V

2) Â&#x; J i (t 3) Â&#x; J t

0)

1 ¡ Ws § J w ¨1 ¸ Vt Š Gs š

1 ¡ N *Ws § Jw ¨1 ¸ Vt Š Gs š

Î?ϴγΎÎ˜Ď&#x;Î? ΔϳÎ?ΪΑ commencement of sedimentation Ď?ÎŽĎ— Î?ÎŤÎ? t = 0.0

JL

Soil Mechanics (1)


Chapter (2) 2011

(8)

Soil Mechanics (1)

Grain Size Distribution


Chapter (2) 2011

(9)

Grain Size Distribution

5)During a sedimentation test for grain size analysis, the corrected hydrometer reading in a 1000 ml uniform soil suspension at the commencement of sedimentation is 1.028. after 30 minutes, the corrected hydrometer reading is 1.012 and the corresponding effective depth is 10.5 cm, determine: i) The total mass of solid dispersed in 1000 ml of suspension. ii)The particle size corresponding to the 30 minutes reading. iii) The percentage finer than this size, take Gs = 2.67 and P = 0.01 poise.

Soil Mechanics (1)


Chapter (2) 2011

(10)

Soil Mechanics (1)

Grain Size Distribution


Chapter (2) 2011

(11)

Grain Size Distribution

6) Particles of 5 different sizes are mixed in the proportions shown below and enough water is added to make 1000 ml of the suspension. The temperature of the suspension is 20o C. Particle size (mm) 0.05 0.02 0.01 0.005 0.001 Weight (gm) 7 20 18 4 5 If it is insured that the suspension is mixed so as have a uniform distribution of particles. All particles have a specific gravity of 2.7, assume Jw = 1 gm/cm3, t = 20o C, P Ň?0.01 poise. i) What is the largest particles size present at a depth of 6 cm after 5 minutes of start sedimentation? ii) What is the specific gravity of the suspension at a depth of 6 cm after 5 minutes of start of sedimentation. iii) How long should be the sedimentation be allowed so that all the particles have settled below 6 cm.

Soil Mechanics (1)


Chapter (2) 2011

(12)

Soil Mechanics (1)

Grain Size Distribution


Chapter (2) 2011

(13)

Soil Mechanics (1)

Grain Size Distribution


Chapter (2) 2011

(14)

Soil Mechanics (1)

Grain Size Distribution


Soil Mechanics (1) Fff


Chapter (3)

Consistency of fine soil

1

2011

Chapter (3) Consistency of fine soil ΔϤϋΎϨϟ΍ ΔΑήΘϟ΍ ϡ΍Ϯϗ ϞϜθΘϟ΍ ϰϠϋ (ΔϴϴϤτϟ΍ ϭ ΔϴϨϴτϟ΍) ΔϤϋΎϨϟ΍ ΔΑήΘϟ΍ ΓέΪϗ Ϧϋ ΓέΎΒϋ Ϯϫ (ςϟΰϟ΍ϭ Ϟϣήϟ΍) ΔϨθΨϟ΍ ΔΑήΘϠϟ ϡΪΨΘδΗ ϻϭ ϡ΍ϮϘϟ΍ ΩϭΪΣ

Atterberg limits (consistency limits): ϩΎϴϤϟ΍ ϒϴϔΠΗ a

a w

w

w

S

S

S

S

w S

ϩΎϴϣ ΔϓΎο·

Volume

Solid State

Semisolid state

S.L.

Plastic state

P.L.

Liquid state

L.L.

Soil Mechanics (1)

Wc


Chapter (3)

Consistency of fine soil

2

2011

1) Liquid limit: (L.L.)

ΔϟϮϴδϟ΍ ΪΣ

ϰϟ· ΔϠ΋Ύδϟ΍ ΔϟΎΤϟ΍ Ϧϣ ΔΑήΘϟ΍ ϝϮΤΘΗ ϩΪϨϋ ϱάϟ΍ ϲ΋ΎϤϟ΍ ϯϮΘΤϤϟ΍ Ϯϫ Ϟ΋΍Ϯδϟ΍ ϙϮϠγ ΔΑήΘϟ΍ ϚϠδΗ ϩΪϨϋ ϱάϟ΍ϭ βϜόϟ΍ ϭ΃ ΔϧΪϠϟ΍ ΔϟΎΤϟ΍ (Γήϴϐλ κϗ ΔϣϭΎϘϣ ΎϬϟ) ΔΟΰϠϟ΍ Casagrande's method:

Ϊϧ΍ήΟ΍ίΎϛ ΔϘϳήσ

Ϊϧ΍ήΟ΍ίΎϛ ίΎϬΟ Ϊϧ΍ήΟ΍ίΎϛ ίΎϬΟ Grooving tools ϖθϟ΍ Γ΍Ω΃

Soil Mechanics (1)


Chapter (3)

Consistency of fine soil

3

2011

:ΔϘϳήτϟ΍ Ε΍ϮτΧ ˽˹ Ϣϗέ ϞΨϨϤϟ΍ Ϧϣ ΓέΎϣ ΔϤϋΎϧ ΔΑήΗ Ϧϣ ΔϨϴϋ έΎπΣ· ϢΘϳ (˺ βϧΎΠΘϣ ςϴϠΧ ϦϳϮϜΘϟ ΪϴΠϟ΍ ΐϴϠϘΘϟ΍ ϊϣ ΔΑήΘϠϟ ˯ΎϤϟ΍ Ϧϣ ΔϴϤϛ ΔϓΎο· (˻ ΔϘΗϮΒϟ΍ ϲϓ Ϫόοϭϭ ςϴϠΨϟ΍ Ϧϣ ˯ΰΟ άΧ΍ (˼ ϲϟϮσ ϖη ϞϤϋ ϢΘϳ ϖθϟ΍ Γ΍Ω΃ ϡ΍ΪΨΘγΎΑ (˽ ϖθϟ΍ Ϧϣ Ϣϣ ˺˼ ϖϠϐϟ Δϣίϼϟ΍ ΕΎΑήπϟ΍ ΩΪϋ ΪϳΪΤΗ ϭ ίΎϬΠϟ΍ ϞϴϐθΗ (˾ ϯήΧ΃ ϩΎϴϣ ΔϴϤϛ ϡ΍ΪΨΘγ΍ ϊϣ ΔϘΑΎδϟ΍ Ε΍ϮτΨϟ΍ βϔϧ έ΍ήϜΗ ϢΘϳ (˿

Wc N ΕΎΑήπϟ΍ ΩΪϋ ϭ ϲ΋ΎϤϟ΍ ϯϮΘΤϤϟ΍ ϦϴΑ Δϗϼόϟ΍ Ϣγέ (̀ liquid limit ϰϠϋ ϝϮμΤϠϟ Wc

L.L. Flow line

Log. (N) N = 25

Soil Mechanics (1)


Chapter (3)

Consistency of fine soil

4

2011

Liquid limit: (L.L.)

ΔϟϮϴδϟ΍ ΪΣ

ϰѧϟ· ΔϠ΋Ύѧδϟ΍ ΔѧϟΎΤϟ΍ Ϧѧϣ ΔѧΑήΘϟ΍ ϝϮΤΘΗ ϩΪϨϋ ϱάϟ΍ ϲ΋ΎϤϟ΍ ϯϮΘΤϤϟ΍ Ϯϫ Ϟ΋΍Ϯѧѧδϟ΍ ϙϮϠѧѧγ ΔѧѧΑήΘϟ΍ ϚϠѧѧδΗ ϩΪѧѧϨϋ ϱάѧѧϟ΍ϭ βѧѧϜόϟ΍ ϭ΃ ΔѧѧϧΪϠϟ΍ ΔѧѧϟΎΤϟ΍ ϖѧѧη ϖѧѧϠϏ ϦѧѧϜϤϳ ϩΪѧѧϨϋ ϱάѧѧϟ΍ ϭ (Γήϴϐѧѧλ κѧѧϗ ΔѧѧϣϭΎϘϣ ΎѧѧϬϟ ) ΔѧѧΟΰϠϟ΍ Ϊϧ΍ήΟ΍ίΎϛ ΔϘϳήσ ϝϼΧ Ϧϣ ϚϟΫϭ ΔΑήο ˻˾ ϡ΍ΪΨΘγΎΑ Ϣϣ ˺˼ ϪϟϮσ 2) Plastic limit: (P.L.)

ΔϧϭΪϠϟ΍ ΪΣ

ϰϟ· ΔϧΪϠϟ΍ ΔϟΎΤϟ΍ Ϧϣ ΔΑήΘϟ΍ ϝϮΤΘΗ ϩΪϨϋ ϱάϟ΍ ϲ΋ΎϤϟ΍ ϯϮΘΤϤϟ΍ Ϯϫ ΔΒϠμϟ΍ ΔΒη ΔϟΎΤϟ΍

:ΔϘϳήτϟ΍ Ε΍ϮτΧ ˽˹ Ϣϗέ ϞΨϨϤϟ΍ Ϧϣ ΓέΎϣ ΔϤϋΎϧ ΔΑήΗ Ϧϣ ΔϨϴϋ έΎπΣ· ϢΘϳ (˺ βϧΎΠΘϣ ςϴϠΧ ϦϳϮϜΘϟ ΪϴΠϟ΍ ΐϴϠϘΘϟ΍ ϊϣ ΔΑήΘϠϟ ˯ΎϤϟ΍ Ϧϣ ΔϴϤϛ ΔϓΎο· (˻

Soil Mechanics (1)


Chapter (3)

5

2011

Consistency of fine soil

ϕΰϤΘϳ ϥ΃ ϥϭΪΑ ςϴΧ ϦϳϮϜΗ ΔϟϭΎΤϣϭ ςϴϠΨϟ΍ Ϧϣ ˯ΰΟ άΧ΍ (˼ ϕΰϤΘϟ΍ Δϳ΍ΪΑ ΪϨϋ ςϴΨϟ΍ ήτϗ ΪϳΪΤΗ (˽ ϯήΧ΃ ϩΎϴϣ ΔϴϤϛ ϡ΍ΪΨΘγ΍ ϊϣ ΔϘΑΎδϟ΍ Ε΍ϮτΨϟ΍ βϔϧ έ΍ήϜΗ ϢΘϳ (˾

Wc d ςϴΨϟ΍ ήτϗ ϭ ϲ΋ΎϤϟ΍ ϯϮΘΤϤϟ΍ ϦϴΑ Δϗϼόϟ΍ Ϣγέ (˿

Wc

Plastic limit ϰϠϋ ϝϮμΤϠϟ

P.L.

d d = 3 mm Plastic limit: (P.L.)

ΔϧϭΪϠϟ΍ ΪΣ

ΔѧϟΎΤϟ΍ ϰѧϟ· ΔѧϧΪϠϟ΍ ΔѧϟΎΤϟ΍ Ϧѧϣ ΔѧΑήΘϟ΍ ϝϮѧΤΘΗ ϩΪѧϨϋ ϱάѧϟ΍ ϲ΋ΎѧϤϟ΍ ϯϮΘΤϤϟ΍ Ϯϫ ϕΰϤΗ ΙϭΪΣ ϥϭΩ Ϣϣ ˼ ϩήτϗ ςϴΧ ϦϳϮϜΗ ϦϜϤϳ ϩΪϨϋ ϱάϟ΍ϭ ΔΒϠμϟ΍ ΔΒη

Soil Mechanics (1)


Chapter (3)

Consistency of fine soil

6

2011

εΎϤϜϧϻ΍ ΪΣ

3) Shrinkage limit: (S.L.)

ϰѧϟ· ΔΒϠѧμϟ΍ ΔΒѧη ΔѧϟΎΤϟ΍ Ϧѧϣ ΔѧΑήΘϟ΍ ϝϮѧΤΘΗ ϩΪѧϨϋ ϱάѧϟ΍ ϲ΋ΎѧϤϟ΍ ϯϮѧΘΤϤϟ΍ Ϯϫ ϱϭΎѧѧδϣ εΎѧѧϤϜϧϻ΍ ΔѧѧϟΎΣ ϲѧѧϓ ˯ΎѧѧϤϟ΍ ϢѧѧΠΣ ϥϮѧѧϜϳ ϩΪѧѧϨϋ ϱάѧѧϟ΍ϭ ΔΒϠѧѧμϟ΍ ΔѧѧϟΎΤϟ΍ .ΔϓΎΠϟ΍ ΔϟΎΤϟ΍ ϲϓ ˯΍ϮϬϟ΍ ϢΠΤϟ

a

w

S

S

dry

S.L.

Va( dry ) Vw( S .L.)

Classify of the soil: (L.L. & P.L. & S.L.)ϡ΍ΪΨΘγΎΑ ΔΑήΘϟ΍ ϒϴϨμΗ 1) Plasticity index ( IP )

ΔϧϭΪϠϟ΍ ήηΆϣ

ΔϧϭΪϠΑ ϪϟϼΧ ΔΑήΘϟ΍ ϑήμΘΗ ϱάϟ΍ ϲ΋ΎϤϟ΍ ϯϮΘΤϤϟ΍ Ϯϫ

Ip

L.L. P.L.

Ip

plasticity

soil

0

Non-plastic

Sand

<7 7-17 >17

Low plastic Med. Plastic High plastic

Silt Silty - clay clay

Soil Mechanics (1)


Chapter (3)

Consistency of fine soil

7

2011

2) Consistency index ( Ic )

ϡ΍ϮϘϟ΍ ήηΆϣ

(Relative plasticity) ϲόϴΒτϟ΍ ΔΑϮσήϟ΍ ϯϮΘΤϣ ϭ ΔϟϮϴδϟ΍ ΪΣ ϦϴΑ ϕήϔϟ΍ ϦϴΑ ΔΒδϨϟ΍ Ϯϫ ΔϧϭΪϠϟ΍ ήηΆϣ ϰϟ·

Ic

L.L. Wc Ip

L.L. Wc L. L P . L.

Ic Soil type 0 Very soft 0-0.25 Soft 0.26-0.5 Med. Stiff 0.51-0.75 Stiff 0.76-1.0 Very stiff >1.0 Extremely stiff 3) Liquidity index ( IL )

ΔϟϮϴδϟ΍ ήηΆϣ

ϰϟ· ΔϧϭΪϠϟ΍ ΪΣ ϭ ϲόϴΒτϟ΍ ΔΑϮσήϟ΍ ϯϮΘΤϣ ϦϴΑ ϕήϔϟ΍ ϦϴΑ ΔΒδϨϟ΍ Ϯϫ ΔϧϭΪϠϟ΍ ήηΆϣ

IL IL

Wc P.L. Ip 1 Ic

Wc P.L. L. L P . L.

Soil Mechanics (1)


Chapter (3)

Consistency of fine soil

8

2011

4) Flow index ( If )

ϥΎϳήδϟ΍ ήηΆϣ

( flow line ) ϥΎϳήδϟ΍ ςΧ Ϟϴϣ Ϧϋ ΓέΎΒϋ Ϯϫ Wc

L.L. Flow line Log. (N)

N = 25

Wc1 Wc 2 log( N 2 ) log( N1 )

If

5) Toughness index ( It )

ΔϧΎΘϤϟ΍ ήηΆϣ

ϥΎϳήδϟ΍ ήηΆϣ ϰϟ· ΔϧϭΪϠϟ΍ ήηΆϣ ϦϴΑ ΔΒδϨϟ΍ Ϯϫ

It

Ip If

Soil Mechanics (1)


Chapter (3)

Consistency of fine soil

9

2011

6) Activity of clay ( Ac )

Ϧϴτϟ΍ ρΎθϧ

ΔϴϨϴτϟ΍ ΔΑήΘϠϟ ϰϤΠΤϟ΍ ήϴϐΘϟ΍ ϯΪϣ ΪϳΪΤΘϟ ήηΆϣ Ϯϫ ϢΠΤϟ΍ ϰϓ ΓΩΎϳί

Collapse soil

ϢΠΤϟ΍ ϰϓ κϘϧ

Ip % fines 0 . 002 mm mm 0.002 Ϧϣ ϞϗϷ΍ ϢϋΎϨϟ΍ ΔΒδϧ

% passing

Ac

Swelling soil

% fines Size 0.002

Ac < 0.75 0.75-1.4 >1.4

activity In-active Med. active active

Soil Mechanics (1)


Chapter (3)

10

2011

Consistency of fine soil

7) Unconfined compression strength ( qu ) (ςϘϓ ϦϴτϠϟ ) ρΎΤϣ ήϴϐϟ΍ ςϐπϟ΍ ΔϣϭΎϘϣ (L/D = 2) Ϧϴτϟ΍ Ϧϣ ΔϨϴϋ έΎπΣ· ϢΘϳ P 'L

P A ' L L

V V

H

qu

H qu

Clay type

0 - 0.25

Very soft clay

0.25 - 0.5

Soft clay

0.5 - 1

Med. clay

1-2

Stiff clay

2-4

Very stiff clay

>4

Hard clay

Soil Mechanics (1)


Chapter (3)

Consistency of fine soil

11

2011

8) Sensitivity of clay ( ˳St )

Ϧϴτϟ΍ ΔϴγΎδΣ

Ϧϣ undisturbed ϪϫϮθϣ ήϴϏ ΔϨϴόϟ ρΎΤϣ ήϴϐϟ΍ ςϐπϟ΍ ΩΎϬΟ· ϦϴΑ ΔΒδϨϟ΍ ϲϫ ϞϴϜθΗ ΓΩΎϋ· ΎϬϟ ΙΪΣ Ϧϴτϟ΍ Ϧϣ ΔϨϴόϟ ρΎΤϣ ήϴϐϟ΍ ςϐπϟ΍ ΩΎϬΟ· ϰϟ· Ϧϴτϟ΍ remolded

qu (undisturbe d ) qu ( remolded )

St St

sensitivity

<1

Insensitive

1–2

Low sensitive

2–4

Med. sensitive

4–8

sensitive

8 – 16

Very sensitive

> 16

Extra sensitive

Quick clay ϰϤδϳ (St > 16) Ϫϟ ϱάϟ΍ Ϧϴτϟ΍ 9) Degree of shrinkage ( ˳D.O.S. )

εΎϤϜϧϻ΍ ΔΟέΩ

ΔΑήΘϠϟ ϲϠλϷ΍ ϢΠΤϟ΍ ϰϟ· ϢΠΤϟ΍ ϲϓ ήϴϐΘϟ΍ έ΍ΪϘϣ ϦϴΑ ΔΒδϨϟ΍ Ϯϫ

D.O.S

Vo Vdry Vo

'V Vo

ϲϠλϷ΍ ϢΠΤϟ΍ =

Vo

ϑΎΠϟ΍ ϢΠΤϟ΍ = Vdry

Soil Mechanics (1)


Soil Mechanics (1) Fff


Zagazig University

Structural Eng. Department

Faculty of Engineering

Ëş

Soil Mechanics (1)

Sheet No. (3) Soil Consistency 1- A) Define: liquid limit, plastic limit, shrinkage limit, plasticity index. B) the liquid an plastic limits of a soil are 87 % and 35 % respectively, natural water content is 43%. Find the liquidity index and draw the relation between the water content and liquidity index for this soil for water content ranging between the plastic and the liquid limits. 2- The following index properties were determined for two soils A & B Property

Soil (A)

Soil (B)

L.L

0.62

0.34

P.L

0.26

0.19

Wc

38 %

25 %

Gs

2.72

2.67

Sr

1.0

1.0

From the above table, determine which of these soils: 1) contains more clay particles 2) Has a greater wet density 3) Has a greater dry density 4) Has a greater void ratio 3- The liquid limit, water content and the plastic limit of clay soil were determined in the laboratory as follows. Find consistency index & liquidity index for each soil:


Zagazig University

Structural Eng. Department Ëť

Faculty of Engineering

Soil Mechanics (1)

Soil

L.L %

Wc %

P.L %

A

15

12

10

B

78

34

28

C

55

40

35

D

41

35

31

4- For the given data determine the liquid limit of a given sample of silt: Moist wt. of sample

7.49

6.41

8.606

7.72

Dry wt. of sample

6.15

5.235

7.006

6.27

Number of blows

40

34

24

20

Determine also the flow and toughness indexes of this soil. 5- Sample of clay soil has a liquid limit of 62 % and its plasticity index is 32 % a) what is the degree of stiffness of this soil if the natural water content is 34 % b) calculate the shrinkage limit if the void ratio of the sample at its shrinkage limit is 70 % , Gs = 2.70 6- Sample of clay weight 34.8 gm at its liquid limit. After drying the clay, its weight is 19.4 gm and its volume is 10 cm3. if the Gs = 2.7 of clay determine its L.L and S.L.


Chapter (3)

Soil Consistency

(1)

2011

Sheet No. (3) Soil Consistency 1- A) Define: liquid limit, plastic limit, shrinkage limit, plasticity index. Liquid limit: (L.L.)

ΔϟϮϴδϟ΍ ΪΣ

ΔϧΪϠϟ΍ ΔϟΎΤϟ΍ ϰϟ· ΔϠ΋Ύδϟ΍ ΔϟΎΤϟ΍ Ϧϣ ΔΑήΘϟ΍ ϝϮΤΘΗ ϩΪϨϋ ϱάϟ΍ ϲ΋ΎϤϟ΍ ϯϮΘΤϤϟ΍ Ϯϫ κѧϗ ΔѧϣϭΎϘϣ ΎѧϬϟ ) ΔѧΟΰϠϟ΍ Ϟ΋΍Ϯѧδϟ΍ ϙϮϠѧγ ΔΑήΘϟ΍ ϚϠδΗ ϩΪϨϋ ϱάϟ΍ϭ βϜόϟ΍ ϭ΃ ϚѧϟΫϭ ΔΑήѧο ˻˾ ϡ΍ΪΨΘѧγΎΑ Ϣϣ ˺˼ ϪϟϮσ ϖη ϖϠϏ ϦϜϤϳ ϩΪϨϋ ϱάϟ΍ ϭ (Γήϴϐλ Ϊϧ΍ήΟ΍ίΎϛ ΔϘϳήσ ϝϼΧ Ϧϣ Plastic limit: (P.L.)

ΔϧϭΪϠϟ΍ ΪΣ

ΔΒѧη ΔѧϟΎΤϟ΍ ϰѧϟ· ΔѧϧΪϠϟ΍ ΔѧϟΎΤϟ΍ Ϧѧϣ ΔѧΑήΘϟ΍ ϝϮΤΘΗ ϩΪϨϋ ϱάϟ΍ ϲ΋ΎϤϟ΍ ϯϮΘΤϤϟ΍ Ϯϫ ϕΰϤΗ ΙϭΪΣ ϥϭΩ Ϣϣ ˼ ϩήτϗ ςϴΧ ϦϳϮϜΗ ϦϜϤϳ ϩΪϨϋ ϱάϟ΍ϭ ΔΒϠμϟ΍ Shrinkage limit: (S.L.)

εΎϤϜϧϻ΍ ΪΣ

ΔѧϟΎΤϟ΍ ϰѧϟ· ΔΒϠѧμϟ΍ ΔΒη ΔϟΎΤϟ΍ Ϧϣ ΔΑήΘϟ΍ ϝϮΤΘΗ ϩΪϨϋ ϱάϟ΍ ϲ΋ΎϤϟ΍ ϯϮΘΤϤϟ΍ Ϯϫ ˯΍ϮѧϬϟ΍ ϢѧΠΤϟ ϱϭΎѧδϣ εΎѧϤϜϧϻ΍ ΔѧϟΎΣ ϲѧϓ ˯ΎϤϟ΍ ϢΠΣ ϥϮϜϳ ϩΪϨϋ ϱάϟ΍ϭ ΔΒϠμϟ΍ .ΔϓΎΠϟ΍ ΔϟΎΤϟ΍ ϲϓ

a

w

S

S

dry

S.L.

Va( dry ) Vw( S .L.)

Soil Mechanics (1)


Chapter (3)

Soil Consistency

(2)

2011

Plasticity index ( IP )

ΔϧϭΪϠϟ΍ ήηΆϣ

ϲѧѧϓ ϡΪΨΘѧѧδϳ ϱάѧѧϟ΍ ϭ ΔѧѧϧϭΪϠΑ ϪѧѧϟϼΧ ΔѧѧΑήΘϟ΍ ϑήѧѧμΘΗ ϱάѧѧϟ΍ ϲ΋ΎѧѧϤϟ΍ ϯϮѧѧΘΤϤϟ΍ Ϯѧѧϫ ΔΑήΘϟ΍ ϒϴϨμΗ

L.L. P.L.

Ip

B) the liquid an plastic limits of a soil are 87 % and 35 % respectively, natural water content is 43%. Find the liquidity index and draw the relation between the water content and liquidity index for this soil for water content ranging between the plastic and the liquid limits. given L.L = 87 % P.L = 35 % Wc = 43 % Req. 1) IL 2) Draw relation (Wc, IL)

IL

Wc P.L. Ip

Wc = 35

43 35 87 35

Soil Mechanics (1)

87

0 .15


Chapter (3)

Soil Consistency

(3)

2011

IL 1.0

0.15 WcËą 43

87

2- The following index properties were determined for two soils A & B Property

Soil (A)

Soil (B)

L.L

0.62

0.34

P.L

0.26

0.19

Wc

38 %

25 %

Gs

2.72

2.67

Sr

1.0

1.0

From the above table, determine which of these soils: 1)Which soil contains more clay particles 2) Has a greater wet density 3) Has a greater dry density 4) Has a greater void ratio

Soil Mechanics (1)


Chapter (3)

Soil Consistency

(4)

2011

1) Which soil contains more clay particles

ÎŽÎœĎ›Îƒ clay Ď°Ď Ď‹ ϹώΘΤΗ ÎŽÎ’Ď›Î? IP ÎŽĎŹĎ&#x; ϲΘĎ&#x;Î? ΔΑΎΘĎ&#x;Î? For soil (A)

Ip Ip

L.L. P .L. 0 .62 0 .26

0 .36

0 .34 0 .19

0 .15

For soil (B)

Ip

Soil (A) has more clay

1.03

w

1.03

0.67

w

0.67

1

S

2.72

1

S

2.67

Soil (A)

Soil (B)

ÎŽÎ’Ď›Î? ĎŚĎŁ ΊΪΤϧ Ď­ ΔΑΎΗ ĎžĎœĎ&#x; Jb Jd e Î?ÎŽδΣ ϢÎ˜Ďł

Soil Mechanics (1)


Chapter (3)

Soil Consistency

(5)

2011

3- The liquid limit, water content and the plastic limit of clay soil were determined in the laboratory as follows. Find consistency index & liquidity index for each soil: Soil L.L % Wc % P.L % A 15 12 10 B 78 34 28 C 55 40 35 D 41 35 31 For soil (A)

Ic IL

L.L Wc . 15 12 15 10 Ip 1 Ic 0 .4

0 .6

For soil (B)

Ic IL

L.L Wc . 78 34 Ip 78 28 1 Ic 0 .12

0 .88

For soil (C)

Ic IL

L.L Wc . 55 40 Ip 55 35 1 Ic 0 .25

0 .75

Soil Mechanics (1)


Chapter (3)

Soil Consistency

(6)

2011

4- For the given data determine the liquid limit of a given sample of silt: Moist wt. of sample

7.49

6.41

8.606

7.72

Dry wt. of sample

6.15

5.235

7.006

6.27

Number of blows

40

34

24

20

Determine also the flow and toughness indexes of this soil. Sol.

Wc

Ww Ws

Wt( moist ) Wt( dry ) Wt( dry )

Wc, %

21.8

22.5

22.8

23.2

Number of blows

40

34

24

20

24.0

23.5

To scale

23.0

22.5

22.0

21.5

21.0 100

25

Soil Mechanics (1)

10


Chapter (3)

Soil Consistency

(7)

2011

L.L = 22.8 % Wc1 Wc 2 If Log ( N 1 ) Log ( N 2 )

If

0.228 0.218 Log ( 40 ) Log ( 24 )

IT

Ip If

0.045

5- Sample of clay soil has a liquid limit of 62 % and its plasticity index is 32 %

a) what is the degree of stiffness of this soil if the natural water content is 34 % b) calculate the shrinkage limit if the void ratio of the sample at its shrinkage limit is 70 % , Gs = 2.70 a)

Ic

LL Wc LL Pl

62 34 32

0.875

b) e = 70 % Gs = 2.7

Soil Mechanics (1)


Chapter (3)

Soil Consistency

(8)

2011

Vv e Vs assume Vs 1 Vv

0.7

w

0.7

1

S

2.7

0 .7

Ww Ws

SL

0 .7 2 .7

SL

φϔΣ

0 . 26

e Gs

φΣϻ φϔΣ

6- Sample of clay weight 34.8 gm at its liquid limit. After drying the clay, its weight is 19.4 gm and its volume is 10 cm3. if the Gs = 2.7 of clay determine its L.L and S.L.

Given

L.L

Wt = 34.8 gm

S.L

Ws = 19.4 gm Vt = 10 cm3

Req.

L.L, P.L

Soil Mechanics (1)

Gs = 2.7


Chapter (3)

Soil Consistency

(9)

2011

S.L

L.L 15.4

7.18

S

Ww SL Ws 15 .4 S .L 19 .4

19.4

79 .4

2.8

w

2.8

7.18

S

19.4

10

w

34.8

15.4

Ww SL Ws 2 .8 S .L 19 .4

Soil Mechanics (1)

14 .5


Soil Mechanics (1) Fff


Chapter (4)

Soil Classification

(1)

2011

Chapter (4) Soil Classification ΔΑήΘϟ΍ ϒϴϨμΗ βѧѧϔϧ ΎѧѧϬϟ ϲѧѧΘϟ΍ ΔѧѧϋϮϤΠϤϟ΍ ϊѧѧϣ ΔѧѧΑήΗ Ϟѧѧϛ ϊѧѧοϭ Ϯѧѧϫ ΔѧѧΑήΘϟ΍ ϒϴϨѧѧμΗ ϦϴѧϤΘϬϤϟ΍ ϦϴΑ ϰϟϭϷ΍ ΐσΎΨΘϟ΍ Δϐϟ ϲϬϓ ϲγΪϨϬϟ΍ ϙϮϠδϟ΍ ϭ ι΍ϮΨϟ΍ .ΔΑήΘϟ΍ ΎϜϴϧΎϜϴϣ ϢϠόΑ :ϲϫ ϒϴϨμΘϠϟ ϕήσ ΓΪϋ ΪΟϮϳϭ 1- Particle size classification (M.I.T. classification) 2- Textural classification 3- Unified soil classification system (U.S.C.S) 4- American Association of Highway and Transportation Officials (AASHTO)

1) Particle size classification (M.I.T. classification) ΎϬϧϮϛ ΚϴΣ Ϧϣ ΔΑήΘϟ΍ ωϮϧ ΪϳΪΤΘϟ ΕΎΒϴΒΤϟ΍ ϢΠΣ ϰϠϋ ϒϴϨμΘϟ΍ ΍άϫ ΪϤΘόϳ -:ϲϠϳ

ΎϤϛ ΝέΪΘϣ αΎϴϘϣ ϝϼΧ Ϧϣ ϚϟΫϭ Ϧϴσ -ϲϤσ – Ϟϣέ – ςϟί

Soil Mechanics (1)


Chapter (4)

Soil Classification

(2)

2011

ΐδϧ ΪϳΪΤΗ ϦϜϤϳ ϱήΧ΃ϭ ΔΑήΗ ϦϴΑ Ϟμϔϳ ϱάϟ΍ Ϣϗήϟ΍ ΔϓήόϤΑ % of gravel

ςϟΰϟ΍ ΔΒδϧ

% of sand

Ϟϣήϟ΍ ΔΒδϧ

% of silt

ϲϤτϟ΍ ΔΒδϧ

% of clay

Ϧϴτϟ΍ ΔΒδϧ

100 P3 P2

P1 0.0 2 mm

0.06 mm

0.002 mm

% of gravel = 100 - P3 % of sand = P3 - P2 % of silt = P2 – P1 % of clay = P1

Soil Mechanics (1)


Chapter (4)

(3)

2011

Soil Classification

2) Textural classification:ΐδϧ ϦϴΑ ςΑήϳ ΚϠΜϣ ϞϜη ϰϠϋ ϊοϭ ϪϧϷ ΚϠΜϤϟ΍ ϒϴϨμΘΑ ϡΎψϨϟ΍ ΍άϫ ϰϤδϳ .ϲϠϳ ΎϤϛ ΔΑήΘϟ΍ ΕΎϧϮϜϣ Ϧϣ ϥϮϜϣ Ϟϛ ΩϮΟϭ ΔΒδϧ ϰϠϋ ΍ΪϤΘόϣ ΔΑήΘϟ΍ ΕΎϧϮϜϣ

Ex: % of sand = 20 % % of clay = 60 %

The soil is Clay

% of silt = 20 % Ex: % of gravel = 7 % % of sand = 25 % % of clay = 25 %

ςϟΰϟ΍ ΔΒδϧ ΩΎόΒΘγ΍ ΪόΑ ΔϟΪόϣ ΐδϧ ΏΎδΣ Ϧϣ ΪΑϻ

% of silt = 43 %

Soil Mechanics (1)


Chapter (4) 2011

% sand % silt % clay

Soil Classification

(4) 25 * 100 26 . 9 % 93 43 * 100 46 . 2 % 93 25 26 . 9 % 93

The soil is Sand-silt-clay

ϲϟΎΘϟ΍ ϝϭΪΠϟ΍ ϡΪΨΘδϧ ΔΑήΘϟ΍ Ϣγ΍ ϲϓ ςϟΰϟ΍ ήϴΛ΄Η ϞΧΪϧ ϰΘΣ ϭ

The soil is Sand-silt-clay % (˺˾-˾) ςϟΰϟ΍ ξόΑ ΎϬΑ 3) Unified soil classification system (U.S.C.S) Γήϴϐλ ϝΎϤΣϷ ΔοήόϤϟ΍ ΔΑήΘϟ΍ ϒϴϨμΘϟ ϡΪΨΘδϳ ΔѧΑήΘϟ΍ ωϮѧϨϟ ΓΰѧϴϤϤϟ΍ ίϮѧϣήϟ΍ ξόΑ ϰϠϋ ΍ΪϤΘόϣ ϒϴϨμΘϟ΍ ϢΘϳ :ϲϠϳ ΎϤϛ ϲϫ ϭ -G -S

Gravel Sand

-O - Pt

Organic soil Peat

Soil Mechanics (1)


Chapter (4) 2011

-M -C -H -L -I

Soil Classification

(5)

Silt -W Well graded Clay -P Poor graded High plasticity Low plasticity Medium plasticity

:ϲϠϳ ΎϤϴϓ ϩέΎμΘΧ΍ ϦϜϤϳ ϝϭΪΟ ϝϼΧ Ϧϣ ϒϴϨμΘϟ΍ ϢΘϳ % passing # 200 = 0.074 mm

% passing # 200 > 50 %

% passing # 200 < 50 %

Fine soil (clay or silt)

Coarse soil (gravel or sand)

Plasticity chart (A-line)

% passing # 4.0 = 4.75 mm

Cassagrand chart % passing # 4.0 > 50 %

Sand

Soil Mechanics (1)

% passing # 4.0 < 50 %

Gravel


Chapter (4)

(6)

2011

Soil Classification

ϕήΤϟΎΑ ϭ΃ ΔΤ΋΍ήϟΎΑ ϭ΃ ήμΒϟΎΑ ΎϬμΤϓ ϢΘϳ ϪϧΎϓ ( peat ) ϢΤϔϠϟ ΔΒδϨϟΎΑ

Plasticity chart (A-line) (Cassagrand chart)

Clay

IP Silt

35 %

50 %

Soil Mechanics (1)

L.L


Chapter (4)

Soil Classification

(7)

2011

4- (AASHTO) ϮΘη΃ AASHTO

Coarse Soil A-1

A-3

A-2

Fine Soil A-4 A-5 A-6 A-7

A-1-a A-1-b

A-7-5 A-7-6

A-2-4 A-2-5 A-2-6 A-2-7

A-1-a ΔѧπϔΨϨϣ ΔϤϋΎϨϟ΍ Ω΍ϮϤϟ΍ Ϧϣ ΔτϴδΑ ΔΒδϧ ϲϠϋ ϱϮΘΤΗ ΝέΪΘϟ΍ ΓΪϴΟ ςϟί Ϧϋ ΓέΎΒϋ ΔϧϭΪϠϟ΍

A-1- b ΓΪϴΟ ΔΑήΗ ήΒΘόΗ ϦθΧ Ϟϣέ Ϧϋ ΓέΎΒϋ

A- 3 ϲϫϭ clay ϭ΃ silt ϲϠϋ ϱϮΘΤϳ ϻ ΕΎΒϴΒΤϟ΍ ΏέΎϘΘϣ ϢϋΎϧ Ϟϣέ Ϧϋ ΓέΎΒϋ ΔϧϭΪϠϟ΍ ΔϤϳΪϋ ΔΑήΗ

Soil Mechanics (1)


Chapter (4) 2011

Soil Classification

(8)

A- 2 ΔΒѧδϧ ΎѧϬϟ ϲѧΘϟ΍ϭ ΔѧϤϋΎϧ Ω΍Ϯѧϣ ϱϮѧΘΤΗ ΔϨѧθΧ Ω΍Ϯѧϣ Ϧѧϣ ω΍Ϯϧ΃ ΓΪϋ Ϧϋ ΓέΎΒϋ ϪϧϭΪϟ

A- 4 ˻˹˹ Ϣϗέ ϞΨϨϣ Ϧϣ ήΜϛ΃ ϭ΃ % ̀˾ ϪϨϣ ήϤϳ silt Ϧϋ ΓέΎΒϋ A- 5 ΔΌϴγ Ω΍Ϯϣ ϭ ΔϴσΎτϣ Ω΍Ϯϣ ϲϠϋ ϱϮΘΤϳ silt Ϧϋ ΓέΎΒϋ

A-6 ˻˹˹ Ϣѧϗέ ϞѧΨϨϣ Ϧѧϣ ήѧΜϛ΃ ϭ΃ % ̀˾ ϪѧϨϣ ήѧϤϳ plastic clay Ϧѧϋ ΓέΎѧΒϋ ϩΎϴϤϟ΍ κΘϤΗ ΎϣΪϨϋ ΎϬΗϮϗ ΪϘϔΗϭ ΓήϴΒϛ ϪϴϤΠΣ Ε΍ήϴϴϐΗ ΎϬϟ ΙΪΤϳϭ

A-7 ΔѧϴσΎτϣ Δѧϧήϣ ι΍ϮѧΧ ΎѧϬϟϭ ϲϟΎѧϋ liquid limit ΎѧϬϟ clay Ϧѧϋ ΓέΎѧΒϋ ΓήϴΒϛ ϪϴϤΠΣ Ε΍ήϴϴϐΗϭ

Soil Mechanics (1)


Chapter (4)

Soil Classification

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2011

ϒϴϨμΘϟ΍ ϢΘϳ ϒϴϛ # 40

A-2

A-3

A-4 A-5 A-6 A-7

50% A-1-b 30% A-1-a 10 15

25

35

# 200

A-2 ϦϴΑ ϖϳήϔΘϟ΍ IP

A-2-6

A-2-7

A-2-4 A

A-2-5

10

40

L.L

Soil Mechanics (1)


Chapter (4)

Soil Classification

(10)

2011

A-4, A-5, A-6, A-7 ϦϴΑ ϖϳήϔΘϟ΍ IP

A-7-6 A-6

A-7-5

10 A-4

A-5 40

L.L

PI < L.L – 30

A-7-5

PI > L.L – 30

A-7-6

Soil Mechanics (1)


Soil Mechanics (1) Fff


Chapter (4)

Soil Classification

(1)

2011

Ex: for the following table Soil # 200 # 4.0

Cu

Cc

LL

Pl

A

30

70

7

2.5

40

25

B

70

100

--

--

60

30

Classify the following soil according to U.S.C.S

Soil (A) - % passing # 200 = 30 % < 50 %

Course soil

- % passing # 4 = 70 % > 50 %

Sand soil

- Cc = 2.5 - Cu = 7 - Ip = L.L – P.L = 40 – 25 = 15

The soil is ( Sw-Sc )

Soil Mechanics (1)


Chapter (4)

Soil Classification

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2011

Soil (B) - % passing # 200 = 70 % > 50 %

Fine soil

A-line ϡ΍ΪΨΘγ΍ ϢΘϳ - Ip = L.L – P.L = 60 – 30 = 30 IP

35 % 50 %

The soil is (CH) Ex: (mid term 2007) Soil # 4.0 # 200 D10 mm D30 mm D60 mm LL Pl A

98

16

0.045

0.13

0.32

48 20

B

44

3

0.16

1.2

4.85

--- ---

C

90

8

0.1

0.32

0.9

36 26

D

100

63

---

---

---

26 26

Soil Mechanics (1)


Chapter (4)

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2011

Soil Classification

Classify the following soil according to U.S.C.S Solution Soil (A) - % passing # 200 = 16 % < 50 %

Course soil

- % passing # 4 = 98 % > 50 %

Sand soil

Cu

D60 D10

0.32 7.11 0.045

(D30 ) 2 Cc D60 * D10

(0.13) 2 1.17 0.32* 0.045

- Ip = L.L – P.L = 48 – 20 = 28

The soil is ( Sw-Sc ) Try of

Soil (B), Soil (C), Soil (D)

Soil Mechanics (1)


Chapter (4)

Soil Classification

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2011

Ex: Soil

# 40

# 200

LL

Pl

A

35

17

-----

-----

B

60

20

60

10

C

90

8

-----

------

D

------

63

49

26

Classify the following soil according to AASHTO Soil (A) - % passing # 200 = 17 % - % passing # 40 = 35 %

Then the soil is (A-1-b)

Soil Mechanics (1)


Chapter (4)

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2011

Soil (B) - % passing # 200 = 20 % - % passing # 40 = 60 %

Then the soil is (A-2)

PI = 60 – 10 = 50 L.L = 60

Then the soil is (A-2-7)

Soil Mechanics (1)

Soil Classification


Chapter (4)

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2011

Soil Classification

Soil (D) - % passing # 200 = 63 %

Then the soil is (A-4) or (A-5) or (A-6) or (A-7)

PI = 49 - 26 = 23 L.L = 49

Then the soil is (A-7) L.L – 30 = 49 – 30 = 19 P.I > L.L – 30 Then the soil is (A-7-6)

Soil Mechanics (1)


Chapter (4)

Soil Classification

(7)

2011

Mid term 2008 Sieve analysis was carried out on a soil sample. The percentage finer than 0.425 mm was used to determine L.L and P.L of the fines. The results are: L.L = 43 %, P.L = 23 % Dim.(mm) 4.76 2.0 1.4 0.6 0.425 0.25 0.15 0.075 % finer

75

60 45 30

25

20

15

10

Classify this soil according to unified system

Soil Mechanics (1)


Chapter (4) 2011

(8)

Soil Mechanics (1)

Soil Classification


Soil Mechanics (1) Fff


Chapter (5)

Soil Compaction

(1)

2011

Chapter (5) Soil Compaction Δ˰˰Αή˰Θϟ΍ Ϛ˰˰ϣΩ

ϲΟέΎΧ ϞϤΣ

Jd

Ws n Vt p

ϖϳήσ Ϧϋ ΔΑήΘϠϟ ΔϓΎΠϟ΍ ΔϓΎΜϜϟ΍ ΓΩΎϳί ΎϬϨϣ νήϐϟ΍ ΔϴϠϤϋ Ϧϋ ΓέΎΒϋ Ϯϫ ϲΟέΎΧ ϞϤΣ ήϴΛ΄Η ΖΤΗ ϚϟΫ ϭ ΕΎΒϴΒΤϟ΍ ϦϴΑ ΕΎϏ΍ήϔϟ΍ κϘϧ Compaction in Lab.

ϞϤόϤϟ΍ ϲϓ ϚϣΪϟ΍

1) Standard proctor test (S.P.T.)

ϲγΎϴϘϟ΍ έϮΘϛϭήΑ έΎΒΘΧ΍

Soil Mechanics (1)


Chapter (5)

Soil Compaction

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2011

-:ΔΑήΠΘϟ΍ Ε΍ϮτΧ .˻˹ Ϣϗέ ϞΨϨϤϟ΍ Ϧϣ ϩέΎϣ ΔϓΎΟ ΔΑήΗ έΎπΣ· ϢΘϳ -˺ .βϧΎΠΘϣ ςϴϠΧ ϦϳϮϜΗ ϭ ΔϓΎΠϟ΍ ΔΑήΘϠϟ ˯ΎϤϟ΍ Ϧϣ ΔϴϤϛ ΔϓΎο· ϢΘϳ -˻ 4–6%

coarse soil

8 – 10 %

fine soil

ΔϘΒσ Ϟϛ ϚϣΩ ϊϣ ΕΎϘΒσ ΙϼΛ ϰϠϋ ΐϟΎϘϟ΍ ϲϓ ςϴϠΨϟ΍ ϊοϭ ϢΘϳ -˼ ωΎϔΗέ΍ Ϧϣ ςϘδΗϭ ϢΠϛ ˻̄˾ ΎϬϧίϭ Δϗήτϣ ϡ΍ΪΨΘγΎΑ ΔΑήο ˻˾ Ϣγ ˼˹̄˾ W1

ύέΎϓ ΐϟΎϘϟ΍ ϥίϭ ΪϳΪΤΗ -˽

W2

ΔΑήΘϟ΍ + ΐϟΎϘϟ΍ ϥίϭ ΪϳΪΤΗ -˾ ΔΑήΘϠϟ ΔϴϠϜϟ΍ ΔϓΎΜϜϟ΍ ΏΎδΣ -˿

W2 W1 Vt 1000

Jb

ΔΑϮσήϟ΍ ϯϮΘΤϣ ΪϳΪΤΗ ϭ ΐϟΎϘϟ΍ ϞΧ΍Ω Ϧϣ ΔΑήΘϟ΍ Ϧϣ ˯ΰΟ άΧ΍ -̀ W3

ϥήϔϟ΍ ϰϓ ΎϬόοϭ ϞΒϗ ΔϨϴόϟ΍ ϥίϭ

W4

ϥήϔϟ΍ Ϧϣ ΎϬΟ΍ήΧ· ΪόΑ ΔϨϴόϟ΍ ϥίϭ

Wc

W3 W4 W4

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Chapter (5)

Soil Compaction

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2011

Î”Î‘ÎŽÎ˜Ď Ď&#x; ΔϓΎΠĎ&#x;Î? Î”Ď“ÎŽÎœĎœĎ&#x;Î? Î?ÎŽδΣ -Ě

Jd

Jb (1 Wc )

ϯΎΧ΃ ĎŠÎŽĎ´ĎŁ ΔΒδϧ ĎĄÎ?ΪΨÎ˜ÎłÎ? ĎŠĎŁ Î”Ď˜Î‘ÎŽδĎ&#x;Î? ΕÎ?ĎŽĎ„ΨĎ&#x;Î? βĎ”ϧ έÎ?ÎŽĎœÎ— -Ě‚

Jd Wc Wc, Jd όϴΑ Î”Ď—ĎźĎŒĎ&#x;Î? Ϣγέ ϢÎ˜Ďł

-˺˚

Jd Jd max.

Wc O.M.C. O.M.C. = Optimum moisture content Jd max. = maximum dry density

Soil Mechanics (1)

ĎžÎœĎŁĎľÎ? Î”Î‘ĎŽĎƒÎŽĎ&#x;Î? ĎŻĎŽÎ˜Τϣ ΔϓΎÎ&#x; Î”Ď“ÎŽÎœĎ› ϲΟĎ—Î?


Chapter (5)

Soil Compaction

(4)

2011

2) Modified proctor test (M.P.T.)

ϝΪόϤϟ΍ έϮΘϛϭήΑ έΎΒΘΧ΍

ϑϼΘΧ΍ ϊϣ standard ˰ϟ΍ βϔϧ Ϯϫ S.P.T.

M.P.T.

Wt. of hammer

2.5 kg

4.5 kg

Drop height

30.5 cm

45 cm

Layers

3 - layers

5 - layers

No. of blows

25 blows

25 blows

Uses

ΔϔϴϔΨϟ΍ ϝΎϤΣϷ΍ ΔϳΩΎόϟ΍ ϕήτϟ΍ ϭ

ΔϠϴϘΜϟ΍ ϝΎϤΣϷ΍ Ε΍έΎτϤϟ΍ ϕήσ ϭ

Factors affecting compaction:

1- Water content

ϚϣΪϟ΍ ϲϓ ήΛ΄Η ϲΘϟ΍ Ϟϣ΍Ϯόϟ΍ ϲ΋ΎϤϟ΍ ϯϮΘΤϤϟ΍

2- Compaction effort

ϚϣΪϟ΍ ΪϬΟ

3- Soil type

ΔΑήΘϟ΍ ωϮϧ

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Chapter (5)

Soil Compaction

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2011

ϲ΋ΎϤϟ΍ ϯϮΘΤϤϟ΍

1- Water content

Jd Jd max.

Dry side

Wet side

Stage ( I )

Stage ( II ) Wc

O.M.C. Stage ( I )

Stage ( II )

ΔϓΎΠϟ΍ ΔϓΎΜϜϟ΍ Ω΍ΩΰΗ ϲ΋ΎϤϟ΍ ϯϮΘΤϤϟ΍ ΓΩΎϳΰΑ

ΔΑϮσήϟ΍ ϯϮΘΤϣ Ϧϋ ϲ΋ΎϤϟ΍ ϯϮΘΤϤϟ΍ ΓΩΎϳΰΑ

ΪϋΎδΗ ˯ΎϤϟ΍ ϥϻ ΔϤϴϗ ϲμϗ΃ ϲϟ· ϞμΗ ϰΘΣ

ϢΠΣ Ϟϐθϳ ˯ΎϤϟ΍ ϥϻ ΔϓΎΠϟ΍ ΔϓΎΜϜϟ΍ ϞϘΗ ϞΜϣϵ΍

ΪϋΎδΗ ΎϤϣ ΎϬπόΑ ϕϮϓ ΕΎΒϴΒΤϟ΍ ϕϻΰϧ΍ ϲϠϋ

ΓΩΎϳί ϰϠϋ ΪϋΎδΗ ΎϤϣ ΕΎϏ΍ήϔϟ΍ Ϧϣ ήϴΒϛ

ΔϓΎΠϟ΍ ΔϓΎΜϜϟ΍ ΓΩΎϳί ϲϟΎΘϟΎΑϭ ϢΠΤϟ΍ κϘϧ ϰϠϋ

ΔϓΎΠϟ΍ ΔϓΎΜϜϟ΍ ϞϘΗ ϲϟΎΘϟΎΑϭ ϢΠΤϟ΍

2- Compaction effort: (E)

ϚϣΪϟ΍ ΪϬΟ

Jd M.P.T.

S.P.T.

Wc

Soil Mechanics (1)


Chapter (5)

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2011

Soil Compaction

E n J d max n O.M .C p ϞΜϣϷ΍ ΔΑϮσήϟ΍ ϱϮΘΤϣ ϞϘϳ ϭ ΔϓΎΠϟ΍ ΔϓΎΜϜϟ΍ ΪϳΰΗ ϚϣΪϟ΍ ΔϗΎσ ΓΩΎϳΰΑ

E

W *H * N *n V W=

ΔϗήτϤϟ΍ ϥίϭ

H = ρϮϘδϟ΍ ωΎϔΗέ΍ N=

ΕΎϘΒτϟ΍ ΩΪϋ

n = ΕΎΑήπϟ΍ ΩΪϋ

E SPT

2 . 5 * 30 . 5 * 3 * 25 1000

5 .7

E MPT

4 . 5 * 45 * 5 * 25 1000

25 . 3

E MPT E SPT

25 . 3 5 .7

4 .4

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Chapter (5) 2011

3- Soil type

Soil Compaction

(7) ΔΑΎΘĎ&#x;Î? ωώϧ

Gravel Sand Silt Clay

Size nÂ&#x; J d max n O .M .C p Î”Î‘ĎŽĎƒÎŽĎ&#x;Î? ϹώΘΤϣ ĎžĎ˜Ďł Ď­ ΔϓΎΠĎ&#x;Î? Î”Ď“ÎŽÎœĎœĎ&#x;Î? ΪϳΰΗ ΕΎΒϴΒΤĎ&#x;Î? ϢΠΣ Î“ΊÎŽϳΰΑ ĎžÎœĎŁĎľÎ?

Soil Mechanics (1)


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Chapter (5)

Soil Compaction

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2011

Compaction in field

ϊϗϮϤϟ΍ ϲϓ ϚϣΪϟ΍

ϝΎѧϤϋ΄Α ΔѧτΒΗήϤϟ΍ ϊϳέΎѧθϤϟ΍ ϲѧϓ Δϴѧδϴ΋ήϟ΍ ΕΎѧΒϠτΘϤϟ΍ ΪѧΣ΍ ΔѧΑήΘϟ΍ ϚѧϣΩ ϞΜϤϳ .Ε΂ѧѧθϨϤϟ΍ ΕΎѧѧγΎγ΃ ϭ ΔѧѧϴΑ΍ήΘϟ΍ ΩϭΪѧѧδϟ΍ ϭ ϕήѧѧτϟ΍ ΎѧѧϬϤϫ΃ Ϧѧѧϣ ϲѧѧΘϟ΍ϭ ΔѧѧΑήΘϟ΍ ήϴΛ΄ѧѧΗ ΖѧѧΤΗ ΔѧѧΑήΘϠϟ ΔѧѧϓΎΠϟ΍ ΔѧѧϓΎΜϜϟ΍ ΓΩΎѧѧϳί ΔѧѧϴϠϤϋ ΎѧѧϬϧ΄Α ϚϣΪѧѧϟ΍ ΔѧѧϴϠϤϋ ϑήѧѧόΗϭ ...ϑΪϬΑ ϚϟΫϭ ϝΎϤΣϷ΍ .ΔΑήΘϟ΍ ϞϤΤΗ ΓέΪϗ ΓΩΎϳί .ΔΑήΘϟ΍ ρϮΒϫ ϞϴϠϘΗ ϲϟΎΘϟΎΑ ϭ ΕΎϏ΍ήϔϟ΍ ΔΒδϧ ϞϴϠϘΗ .ΔϴηΎϤϜϧϻ΍ ϭ ΔϴηΎϔΘϧϹ΍ ΔΑήΘϠϟ ΔϴϤΠΤϟ΍ Ε΍ήϴϐΘϟ΍ ϞϴϠϘΗ .ϩΎϴϤϠϟ ΔΑήΘϟ΍ ΔϳΫΎϔϧ ϞϴϠϘΗ .ΔΑήΘϠϟ ϥΎϣϵ΍ ϞϣΎόϣ ΓΩΎϳί ΔΑήΘϟ΍ ωϮϧ ϰϠϋ ΪϤΘόΗ ΔϔϠΘΨϣ Ε΍Ϊόϣ ϡ΍ΪΨΘγΎΑ ϊϗϮϤϟ΍ ϲϓ ΔΑήΘϟ΍ ϚϣΩ ϢΘϳ :ϲϟΎΘϟ΍ Ε΍ΪόϤϟ΍ Γάϫ Ϧϣϭ

1- Smooth wheel rollers:

Δϴτϟΰϟ΍ ϭ ΔϴϠϣήϟ΍ ΔΑήΘϟ΍ ϚϣΪϟ ϡΪΨΘδϳ

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Chapter (5)

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Soil Compaction

2- Pneumatic-type rollers:

ΔϜγΎϤΘϣ ήϴϐϟ΍ϭ ΔϜγΎϤΘϤϟ΍ ΔΑήΘϠϟ ϡΪΨΘδϳ 3- Sheep-foot rollers

Ϧϴτϟ΍ϭ ϲϤτϟ΍ ϞΜϣ ΔϜγΎϤΘϤϟ΍ ϭ ΔΟΰϠϟ΍ ΔΑήΘϠϟ ϡΪΨΘδϳ

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Chapter (5) 2011

(3)

Soil Compaction

4- Compaction by rammers

ϡ ˼-˻ ϰϟ· ϞμΗ ϕΎϤϋϷ ΔΑήΘϟ΍ ϚϣΪϟ ϡΪΨΘδϳ 5- Dynamic compaction

Δϴτϟΰϟ΍ ϭ ΔϴϠϣήϟ΍ ΔΑήΘϟ΍ ϭ ϡΩήϟ΍ ΔΑήΗ

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Chapter (5)

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2011

Soil Compaction

6- Vibrating plates

(ΔϴϠϣήϟ΍ ΔΑήΘϠϟ) Γήϴϐμϟ΍ ΕΎΣΎδϤϠϟ ϡΪΨΘδϳ 7- Vibrofloating

ϭ ΔϜϜϔϤϟ΍ ΔϴϠϣήϟ΍ ΔΑήΘϟ΍ ϚϣΪϟ ϡΪΨΘδϳ ΓήϴΒϛ ϕΎϤϋϷ Δϴτϟΰϟ΍

Soil Mechanics (1)


Chapter (5)

Soil Compaction

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2011

Relative Compaction (R.c)

ϲΒδϨϟ΍ ϚϣΪϟ΍

ϻ ϡ΃ ϝϮΒϘϣ ϊϗϮϤϟ΍ ϲϓ ϚϣΪϟ΍ ϲϠϋ ϢϜΤϠϟ ϡΪΨΘδϳ

J d field J d max

Rc

ϥ΍ ϲϠϋ ΕΎϔλ΍ϮϤϟ΍ κϨΗϭ

Rc > 95 % Refused

Accepted

Refused

Jd max Jd max Range of Wc

Wc1

O.M.C Wc2

Range of Wc = (O.M.C – Wc1)

(O.M.C + Wc2)

ϰϠϋ ΕΎϔλ΍ϮϤϟ΍ κϨΗ ϭ Range of Wc = (O.M.C ± 2%) ϚϣΪϟ΍ ΓΩΎϋ·ϭ ϩΎϴϣ ΔϓΎο· ϢΘϳ Wc1 ϞΒϗ ϊϘϳ ϭ νϮϓήϣ ϚϣΪϟ΍ ϥΎϛ Ϯϟ ϚϣΪϟ΍ ΓΩΎϋ·ϭ ϒΠΘϟ ΔΑήΘϟ΍ ϙήΗ ϢΘϳ Wc2 ΪόΑ ϊϘϳ ϭ νϮϓήϣ ϚϣΪϟ΍ ϥΎϛ Ϯϟ -

Soil Mechanics (1)


Chapter (5)

Soil Compaction

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2011

Sand cone test:

ϲϠϣήϟ΍ ρϭήΨϤϟ΍ έΎΒΘΧ΍

(Sand replacement test) (Compacted control test)

-: ΔΑήΠΘϟ΍ Ε΍ϮτΧ W1 ήϔΤϟ΍ ΞΗΎϧ ϊϴϤΠΗ ϊϣ ϊϗϮϤϟ΍ ϲϓ ΓήϔΣ ϞϤϋ ϢΘϳ -˺ Wc ϲ΋ΎϤϟ΍ ϯϮΘΤϤϟ΍ ΪϳΪΤΗ ϭ ϥήϔϟ΍ ϲϓ ΔΑήΘϟ΍ ϒϴϔΠΗ ϢΘϳ -˻ ϡ΍ΪΨΘγΎΑ ϞϣήϟΎΑ ΓήϔΤϟ΍ ˯Ϟϣ ϢΘϳ ΔϓΎΜϜϟ΍ ϡϮϠόϣ Ϟϣέ ϡ΍ΪΨΘγΎΑ -˼ ΔϓΎΜϜϟ΍ ρϭήΨϣ

Soil Mechanics (1)


Chapter (5)

Soil Compaction

(7)

2011

ϢΠΣ ΏΎδΣ ϢΘϳ ΓήϔΤϟ΍ ϲϓ ΩϮΟϮϤϟ΍ Ϟϣήϟ΍ ϥίϭ ΔϴϣϮϠόϤΑ -˽

W sand

V hole

ΓήϔΤϟ΍

J sand ΔΑήΘϠϟ ΔϴϠϜϟ΍ ΔϓΎΜϜϟ΍ ΪϳΪΤΗ -˾

W1 V hole

Jb

ΔΑήΘϠϟ ΔϓΎΠϟ΍ ΔϓΎΜϜϟ΍ ΪϳΪΤΗ -˿

J d field Rc

Jb (1 Wc )

J d field J d max

Air void ratio (na)

˯΍ϮϬϟ΍ ΔΒδϧ Va

na

Va Vt

Vt

ΔΑήΘϠϟ ϰϠϜϟ΍ ϢΠΤϟ΍ ϰϟ· ˯΍ϮϬϟ΍ ϢΠΣ ϦϴΑ ΔΒδϨϟ΍ ϲϫ

Soil Mechanics (1)


Chapter (5)

Soil Compaction

(8)

2011

Relation (na, n, Sr) Vv n(1-Sr) n n n*Sr Vt 1 Vw Vw 1-n Sr Vv n Vw n * Sr Va na n (1 Sr ) Vt Relation (na, Gs, Wc, Jd, Jw) Vt

Vs Vw Va

Va

Vt Ï°Ï Ï‹ ΔϤδϘÏ&#x;ΎΑ

Vs Vw Va Vt Vt Vt Vs Vw (1 na ) Vt Vt

Vt

Vw

1

(1 na) (1 na)

Ws Ww Ws * Gs*J w *Vt J w *Vt Ws

Jd Gs*J w

J d *Wc Jw

Vs

Note

Jd Ww Ws

Jd

(1 na ) * Gs * J w (1 Gs * Wc )

Wc

Soil Mechanics (1)

Ws Vt

J w * Vw Gs * J w * Vs Ww Ws


Chapter (5)

Soil Compaction

(9)

2011

Zero air voids: (ZAV)

na = 0 Saturation line

Jd

Gs * J w (1 Gs * Wc )

-: ˰Α ΰϴϤΘϳϭ Ď‚Ď˜Ď“ ϹΎĎˆϧ ϰϨΤϨϣ ĎŽĎŹĎ“ ĎžϤĎŒϤĎ&#x;Î? Ď°Ď“ ÎŞÎ&#x;ĎŽĎł Ďť ϰϨΤϨϤĎ&#x;Î? Î?ÎŹĎŤ .ϚϣΪĎ&#x;Î? ϰϨΤϨϣ βϤϳ Ďť -Ëş .ËŻÎŽϤĎ&#x;Î? Ď°Ď“ Î?΋Î?ÎŤ ËŻÎ?ĎŽĎŤ ΊώÎ&#x;ĎŽĎ&#x; ĎšĎ&#x;ÎŤ Ď­ Î”ĎŒĎ´Î’Ď„Ď&#x;Î? Ď°Ď“ ÎŞÎ&#x;ĎŽĎł Ďť -Ëť ϚϣΪĎ&#x;Î? ϰϨΤϨϣ ΔΤΝ Ď°Ď Ď‹ ϢĎœÎ¤Ď Ď&#x; ϥΪΨΘδϳ -Ëź

5% 10 %

For 5 % of air voids Jd (5 %) = 0.95 * Jd (zav) For 10 % of air voids Jd (10 %) = 0.9 * Jd (zav)

Soil Mechanics (1)

ZAV


Soil Mechanics (1) Fff


Chapter (5)

Soil Compaction

2011

Sol. Wc, %

10.1 11.8 14.2 16.3 17.6 18.9

Jd, t/m3

1.65 1.71 1.79

Jd, t/m3(na = 0)

1.8

1.76 1.72

2.1

2.04 1.94 1.86 1.82 1.78

Jd, t/m3(na = 5%) 2.0

1.93 1.84 1.77 1.73 1.69

2.2 2.1 2 1.9 1.8 1.7 1.6 1.5 10

11

12

13

14

15

16

17

Soil Mechanics (1)

18

19

20


Chapter (5)

Soil Compaction

2011

Sol. Given:Jd t/m3 g/cm3

Wc = 12.5 % 10 cm

Gs = 2.66 Req. 1) Sr 2) na 3) Ww, Wdry

5.0

V

S 4

( 5 ) 2 * 10

a

196.3

42.95

w

42.95 386.55

129.2

S

343.6

Soil Mechanics (1)

196 . 3


Chapter (5)

Soil Compaction

2011

Ws Vt Ww Wc Ws Vw Sr Vv Va na Vt

Jd

Ws 혺혺 Ws 343 .6 196 .3 Ww 0.125 혺혺 Ww 42.95 343 .6 42.95 0.616 69.7 24.15 0.123 196 .3

1.75

Ww 42.95 Ws Wdry 343 .6

Rc = 95 %

Req. Range of water content

Soil Mechanics (1)


Chapter (5)

Soil Compaction

2011 1.9 1.85 1.8 1.75 1.7 1.65 1.6 5

10

Wc1

15

Wc2

20

Range of water content = ( 11.5 – 17.4 )

Soil Mechanics (1)

25


Chapter (5)

Soil Compaction

2011

Soil Mechanics (1)


Chapter (5)

Soil Compaction

2011

Soil Mechanics (1)


Chapter (5)

Soil Compaction

2011

Soil Mechanics (1)


Chapter (5)

Soil Compaction

2011

Soil Mechanics (1)


Chapter (5)

Soil Compaction

2011

Final (2008) In a highway construction 95 % compaction is required for the soil at a moisture content = optimum – 2 % to + 2 %. The soil has the following compaction curve:Wc %

14

16

18

20

22

24

Jd (gm/cm3) 1.89 2.139 2.17 2.21 2.119 2.069 If a sample 900 cm3 volume is taken from the compacted layer. Its weight is 1.8 kg and lost 0.3 kg after drying. Gs = 2.7. i)

Is that sample meet the specification? why?

ii)

What is the degree of saturation of this sample?

Soil Mechanics (1)


Chapter (5)

Soil Compaction

2011

Final (2007)

1.95 dry unit weight, g/cc

The adjacent figure shows the results from a laboratory standard Proctor test. Find the maximum dry density and the optimum moisture content. If the contractor is asked to attain a relative compaction of 95 % what is the minimum dry density that is allowed and the corresponding range of moisture content

1.9 1.85 1.8 1.75 4

Soil Mechanics (1)

9 14 water content, %

19


Chapter (5)

Soil Compaction

2011

Mid term (2008) As a part of compaction control druing the construction of an embankement, a series of density tests were conducted by using sand replacement method (sand cone)and the following data were reported for one of the tests:Weight of the soil excavated from hole = 1080 gm Weight of the soil excavated from hole after dry = 930 gm Weight of the sand filling the hole and cone = 1790 gm Volume of the cone = 750 cm3 Bulk denisty of sand used in the test = 1.42 gm/cm3 The compaction test was carried out on the same soil in the laboratory (volume of the mould = 950 cm3). The following results were obtained: Observation No. 1 2 3 4 5 6 Weight of wet soil, gm 1700 1890 2030 1990 1960 1920 Water content, % 7.7 11.5 14.6 17.5 19.5 21.2 The specific gravity of soil grains = 2.7 i) Calculate the dry denisty, void ratio, degree of saturation and air content of the soil in both site and laboratory ii) Determine the relative compaction. Comment on the results. iii) If the soil gets fully saturated calculate the changes in its water content and bulk density (assume, total volume remains same)

Soil Mechanics (1)


Chapter (5)

Soil Compaction

2011

Soil Mechanics (1)


Chapter (5)

Soil Compaction

2011

Soil Mechanics (1)


Chapter (5)

Soil Compaction

2011

Soil Mechanics (1)


Chapter (5)

Soil Compaction

2011

Soil Mechanics (1)


Chapter (5)

Soil Compaction

2011

Soil Mechanics (1)


Chapter (5)

Soil Compaction

2011

Soil Mechanics (1)


Chapter (5)

Soil Compaction

2011

Soil Mechanics (1)


Chapter (5)

Soil Compaction

2011

Soil Mechanics (1)


Soil Mechanics (1) Fff


Mid-Term Exam 2011

Mid-Term Exam ˺

Soil Mechanics (1)

2011


Soil Mechanics (1) Fff


Chapter (6)

Hydraulic properties

1

2011

of soil

Chapter (6) Hydraulic properties of soil Î”Î‘ÎŽÎ˜Ď Ď&#x; Î”Ď´ĎœĎ´Ď&#x;ϭέΪϴϏĎ&#x;Î? ΚÎ?ώΨĎ&#x;Î? ÎŽĎŹĎ&#x;ϟΧ ĎŚĎŁ ËŻÎŽϤĎ&#x;Î? έϭΎϣ ËŻÎŽϨΛÎ? ΔΑΎΘĎ&#x;Î? Ď™ĎŽĎ Îł ΔγÎ?έΊ ĎŽĎŤ Ď°ĎŤ ËŻÎ?ΰÎ&#x;Î? ΙϟΛ ΔγÎ?έΊ ϢÎ˜Ďł Ď­

Geo-static stress

Permeability

Flow net

νέϾÎ? ĎĽÎŻĎ­ ĎŚĎŁ ΞΗΎϨĎ&#x;Î? ΊÎŽĎŹÎ&#x;ĎľÎ?

Δϳ΍ÎŽĎ”ϨĎ&#x;Î?

ĎĽÎŽϳΎδĎ&#x;Î? Î”ĎœÎ’Ρ

νέϾÎ? ĎĽÎŻĎ­ ĎŚĎŁ ΞΗΎϨĎ&#x;Î? ΊÎŽĎŹÎ&#x;ĎľÎ?

1) Geo-static stress

a) Effective stress: ( V )

Ď?ÎŽĎŒĎ”Ď&#x;Î? ΊÎŽĎŹÎ&#x;ĎťÎ?

ΔΑΎΘĎ&#x;Î? ΕΎΒϴΒΣ ĎĽÎŻĎ­ ĎŚĎŁ ΞΗΎϨĎ&#x;Î? ΊÎŽĎŹÎ&#x;ĎťÎ? ĎŽĎŤ

ÂŚ

V ËŻÎŽϤĎ&#x;Î? ΖΤΗ Jsub.

Jsub. = Jsat. Jw

J *h ËŻÎŽϤĎ&#x;Î? Ď•ĎŽĎ“ J ĎŠÎŽĎ„ĎŒϤĎ&#x;Î? Jb Jd Jsat.

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2

2011

of soil

-:ϝΎόϔϟ΍ ΩΎϬΟϹ΍ ΔϴϤϫ΃ ΔϴϤΠΤϟ΍ Ε΍ήϴϐΘϟ΍ Ϧϋ ΔϟϮΌδϤϟ΍ -˺ ( W ) κϘϟ΍ ΔϣϭΎϘϣ Ϧϋ ΔϟϮΌδϤϟ΍ -˻ b) Pore water pressure: (neutral stress)

˯ΎϤϟ΍ ςϐο

˯ΎϤϟ΍ ϥίϭ Ϧϣ ΞΗΎϨϟ΍ ΩΎϬΟϹ΍ Ϯϫ

¦J

U

w

* hw

Jw ˯ΎϤϟ΍ ΔϓΎΜϛ hw = ˯ΎϤϟ΍ ΢τγ ϦϴΑ ϭ ΎϫΪϨϋ ΏΎδΤϟ΍ ΏϮϠτϤϟ΍ ΔτϘϨϟ΍ ϦϴΑ Δϴγ΃ήϟ΍ ΔϓΎδϤϟ΍

c) Total stress: ( V )

ϰϠϜϟ΍ ΩΎϬΟϻ΍

˯ΎϤϟ΍ ϥίϭϭ ΔΑήΘϟ΍ ΕΎΒϴΒΣ ϥίϭ Ϧϣ ΞΗΎϨϟ΍ ΩΎϬΟϻ΍ Ϯϫ

V ˯ΎϤϟ΍ ΖΤΗ Jsat.

V

¦J *h ˯ΎϤϟ΍ ϕϮϓ J ϩΎτόϤϟ΍ Jb Jd Jsat.

V U

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

3

2011

of soil

Ϟ΋ΎδϤĎ&#x;Î? ĎžΤĎ&#x; ÎŽĎŹĎˆĎ”ÎŁ Î?ĎŽĎ Ď„ĎŁ Ď?Ď­ĎľÎ? ϞΟϔĎ&#x;Î? ĎŚĎŁ όϴϧÎ?ĎŽĎ˜Ď&#x;Î? ΞĎŒÎ‘

Â&#x; sr * e Gs *Wc Â&#x; Jb

§ Gs sr * e ¡ ¨ ¸ *J w Š 1 e š

Ex:Find the stress at point A, B

Jb

h1 B

Jsat.

h2 A At point (A):-

V

ÂŚJ * h

J b * h1 J sat. * h2

U J w * hw J w * h2

V J b * h1 J sub. * h2 Soil Mechanics (1)


Chapter (6)

Hydraulic properties

4

2011

of soil

At point (B):-

V

¦J *h

J b * h1

U

J w * hw

Zero

V

J b * h1 Δϳήόθϟ΍ ΔϴλΎΨϟΎΑ ˯ΎϤϟ΍ ωΎϔΗέ΍ ΔϟΎΣ ϰϓ 1

h1

Jb 2 3

hc

Jsat.

4

Jsat.

h2 5

At point (1):-

V U

zero zero

V

zero Soil Mechanics (1)


Chapter (6)

Hydraulic properties

5

2011

of soil

At point (2):-

V

J b * h1

U

zero

V

J b * h1

At point (3):-

V

J b * h1 U J w * hc V

V U

J b * h1 J w * hc

At point (4):-

V

J b * h1 J sat . * h c

U

zero

V

J b * h1 J sat . * h c

At point (5):-

V

J b * h1 J sat. * hc J sat. * h2 U J w * h2 V

J b * h1 J sat. * hc J sub. * h2 Soil Mechanics (1)


Chapter (6)

Hydraulic properties

6

2011

Surcharge

of soil

ωίώϤĎ&#x;Î? ĎžϤΤĎ&#x;Î? ΎϴΛ΄Η

h1

Jb

h2

Jsat. A

At point (A):-

V

q J b * h1 J sat . * h2

U

J w * h2

V

q J b * h1 J sub. * h2

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

7

2011

of soil

νέϝÎ? ΢Ď„Îł Ď°Ď Ď‹Î? ËŻÎŽϤĎ&#x;Î? ΖϧÎŽĎ› Î?ÎŤÎ?

h1

Jw

h2

Jsat. A

At point (A):-

V U

J sat . * h2 J w * h1 J w * ( h1 h2 )

V

J sub . * h2

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

8

2011

of soil

ϥΎϳήδϟ΍ ήϴΛ΄Η

Effect of flow

a) Down-ward flow (ϰσ΍Ϯϟ΍ Ϧϋ ϰϟΎόϟ΍ ˯ΎϤϟ΍ ΏϮδϨϣ ϕήϓ ) H

ϞϔγϷ ϥΎϳήδϟ΍ h1 Soil Jsat

h2 A

A

At point (A-A):-

V J sat. * h2 J w * h1

ήϴϐΘϳ ϻ ΖΑΎΛ

U J w * (h1 h2 ) J w * H

Jw + έ΍ΪϘϤΑ ϞϘϳ

ΔϤϳΪϘϟ΍ ΔϤϴϘϟ΍

V J sub. * h2 J w * H

Jw + έ΍ΪϘϤΑ Ϊϳΰϳ

ΔϤϳΪϘϟ΍ ΔϤϴϘϟ΍ ϝΎόϔϟ΍ ΩΎϬΟϻ΍ Ω΍Ωΰϳ Ϟϔγϻ ˯ΎϤϟ΍ ΔϛήΣ ϥ΍ φΣϼϧ Jw + έ΍ΪϘϤΑ

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

9

2011

of soil

Ď°Ď Ď‹ϡ ĎĽÎŽϳΎδĎ&#x;Î?

b) Up-ward flow H

h1 Soil Jsat

h2 A

A

At point (A-A):-

V J sat. * h2 J w * h1

ÎŽĎ´Ď?Î˜Ďł Ďť ΖΑΎΛ

U J w * (h1 h2 ) J w * H

Jw + έÎ?ÎŞĎ˜ϤΑ Ϊϳΰϳ

ΔϤϳΪĎ˜Ď&#x;Î? ΔϤϴĎ˜Ď&#x;Î?

V J sub. * h2 J w * H

Jw + έÎ?ÎŞĎ˜ϤΑ ĎžĎ˜Ďł

ΔϤϳΪĎ˜Ď&#x;Î? ΔϤϴĎ˜Ď&#x;Î? Ď?ÎŽĎŒĎ”Ď&#x;Î? ΊÎŽĎŹÎ&#x;ĎťÎ? ĎžĎ Ď˜Ďł Ď°Ď Ď‹Ďť ËŻÎŽϤĎ&#x;Î? ΔϛΎΣ ĎĽÎ? φΣϟϧ Jw + έÎ?ÎŞĎ˜ϤΑ

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

10

2011

Hydraulic gradient (

i

H

)

of soil

ϰϜϴϟϭέΪϴϬϟ΍ ϞϴϤϟ΍

T

h1

h2

L

i i

tan T H L

.......... .......... ....

ϰσ΍Ϯϟ΍ Ϧϋ ϰϟΎόϟ΍ ˯ΎϤϟ΍ ΏϮδϨϣ ϕήϓ ΔΑήΘϟ΍ ϞΧ΍Ω ˯ΎϤϟ΍ έΎδϣ ϝϮσ

ϥϮϜϳ ϥΎϳήδϟ΍ Ϛηϭ ϰϠϋ ΔΑήΘϟ΍ ϥϮϜΗ ΎϣΪϨϋ ϭ

V J sub. * h2 J w * H J sub. * h2 J w * H H J sub. icr h2 J w

zero

Soil Mechanics (1)


Chapter (6)

11

2011

i cr

icr

J sub. Jw

Hydraulic properties of soil

Critical Hydraulic gradient

Gs 1 1 e

ΔΑήΘϟ΍ ι΍ϮΧ Ϧϣ ΔϴλΎΧ

Piping = boiling = heaving = quick sand ϥ΍έϮϔϟ΍ ΓήϫΎχ ϭ (shear stress ) κѧϘϟ΍ Ε΍ΩΎϬΟ΍ Ϟϛ ΔΑήΘϟ΍ ΎϬϴϓ ΪϘϔΗ ΓήϫΎχ ϲϫ ˯ΎѧѧϨΛ΍ ϚѧѧϟΫϭ ( V

) ΔѧѧϛήΤϟ΍ Ϛѧѧηϭ ϰѧѧϠϋ ΔѧѧΑήΘϟ΍ ϥϮѧѧϜΗ ΎѧѧϬϴϓ ϰѧѧΘϟ΍

ΔѧΑήΘϟ΍ ϰѧϓ ΎѧΒϟΎϏ ΙΪΤΗ ΓήϫΎχ ϲϬϓ .ϰϠϋ΃ ϰϟ· Ϟϔγ΍ Ϧϣ ˯ΎϤϟ΍ έϭήϣ .ΔϴϨϴτϟ΍ ΔΑήΘϟ΍ ϰϓ ΓέΩΎϧϭ ΔϴϠϣήϟ΍

Scour ήΤϧ

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

12

2011

of soil

:Î?ÎŽδΣ ϢÎ˜Ďł ĎĽÎ?έώĎ”Ď&#x;Î? ΓΎύΎχ ΙϭΪΣ Ď°Ď Ď‹ ϢĎœÎ¤Ď Ď&#x;

i

H L

icr

J sub. Jw

Gs 1 1 e

i icr Â&#x; No ˜ piping

ĎĽÎ?έώĎ“ ΙΪΤϳ Ďť

icr Â&#x; critical

ĎĽÎ?έώĎ”Ď&#x;Î? ĎšΡϭ Ď°Ď Ď‹

i ! icr Â&#x; piping

ĎĽÎ?έώĎ“ ΙΪΤϳ

i

How to prevent (overcome) piping

ĎĽÎ?έώĎ”Ď&#x;Î? ĎŠϨϣ

ΔΑΎΘĎ&#x;Î? ĎžΧÎ?Ί ËŻÎŽϤĎ&#x;Î? έÎŽδϣ Ď?ĎŽĎƒ ΓΊÎŽϳί -Ëş

Sheet pile wall ΔϴϧΪĎŒĎŁ ÎŽÎ‹ÎŽÎ˜Îł

Soil Mechanics (1)


Chapter (6)

13

2011

Hydraulic properties of soil

΄θϨϤϟ΍ ϒϠΧ ϥ΍ίϭ΍ ϊοϭ -˻ Weights

filters ΕΎΤηήϣ ϡ΍ΪΨΘγ΍ -˼

Filters

Design of filter: -: ˰Α ΢ηήϤϟ΍ ΔΑήΗ ΰϴϤΘΗ ΝέΪΘϟ΍ ΓΪϴΟ ΔΑήΗ -˺ % ˾ Ϧϋ Ϊϳΰϳ ϻ ˻˹˹ Ϣϗέ ϞΨϨϤϟ΍ ϰϠϋ έΎϤϟ΍ -˻

4 D85 ( soil ) ! D15 ( filter ) ! 4 D15 ( soil ) -˼ Soil Mechanics (1)


Chapter (6)

Hydraulic properties

14

2011

of soil

85 % Soil

Filter

B

15 %

A

4D85 D85 4D15 D15 (D15)

15% έΎϣ ΔΒδϧ ΪϨϋ ήτϘϟ΍ ΪϳΪΤΗ -˺

(A) ΔτϘϧ ϰϠϋ ϝϮμΤϠϟ ϲγ΃έ ϊϠτϧ ΎϬϨϣ ϭ (4D15) ϥΎϜϣ ΪϳΪΤΗ -˻ (D85)

85% έΎϣ ΔΒδϧ ΪϨϋ ήτϘϟ΍ ΪϳΪΤΗ -˼

(B) ΔτϘϧ ϰϠϋ ϝϮμΤϠϟ ϲγ΃έ ϊϠτϧ ΎϬϨϣ ϭ (4D85) ϥΎϜϣ ΪϳΪΤΗ -˽ filter ΔϘτϨϣ ϥϮϜΗ ϲΘϟ΍ ϭ ΔΑήΘϟ΍ ϰϨΤϨϤϟ ϥΎϳί΍Ϯϣ ϥΎϴϨΤϨϣ Ϣγήϧ A, B Ϧϣ -˾

filter ˰ϟ΍ ΔϘτϨϣ ϲϓ ϊϘϳ ΔΑήΗ ϰϨΤϨϣ ϱ΃ filter ϥϮϜΗ ϥ΃ ΔΑήΘϟ΍ ϩάϫ ΢ϠμΗ ΍Ϋ· Soil Mechanics (1)


Soil Mechanics (1) Fff


Chapter (6)

Hydraulic properties

1

2011

of soil

Chapter (6) Hydraulic properties of soil ΔΑήΘϠϟ ΔϴϜϴϟϭέΪϴϬϟ΍ ι΍ϮΨϟ΍ ΎϬϟϼΧ Ϧϣ ˯ΎϤϟ΍ έϭήϣ ˯ΎϨΛ΍ ΔΑήΘϟ΍ ϙϮϠγ Δγ΍έΩ Ϯϫ ϰϫ ˯΍ΰΟ΍ ΙϼΛ Δγ΍έΩ ϢΘϳ ϭ

Geo-static stress

Permeability

Flow net

νέϵ΍ ϥίϭ Ϧϣ ΞΗΎϨϟ΍ ΩΎϬΟϵ΍

ΔϳΫΎϔϨϟ΍

ϥΎϳήδϟ΍ ΔϜΒη

ΔΑήΘϟ΍ ΔϳΫΎϔϧ

2) Permeability of soil

ΎϬϟϼΧ Ϧϣ ˯ΎϤϟ΍ έϭήϤΑ ΡΎϤδϟ΍ ϰϠϋ ΔΑήΘϟ΍ ΓέΪϗ ϰϫ K ΔϳΫΎϔϨϟ΍ ϞϣΎόϤΑ ΎϬϨϋ ήΒόϳ ϭ K = Coefficient of permeability Darcy Law

ϰγέ΍Ω ϥϮϧΎϗ i

h1

h2 V

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2

2011

of soil

V vi ϊϣ ϱΩήσ ΐγΎϨΘΗ ΔΑήΘϟ΍ ϰϓ ˯ΎϤϟ΍ ϥΎϳήγ Δϋήγ ϲϜϴϟϭέΪϴϬϟ΍ ϞϴϤϟ΍

V V

const . * i K *i -: ΚϴΣ ΔΑήΘϟ΍ ϞΧ΍Ω ˯ΎϤϟ΍ ϥΎϳήγ Δϋήγ = V ΔϳΫΎϔϨϟ΍ ϞϣΎόϣ = K ϰϜϴϟϭέΪϴϬϟ΍ ϞϴϤϟ΍ = i

i

H L

.......... .......... ....ϕήϓ ϰσ΍Ϯϟ΍ Ϧϋ ϰϟΎόϟ΍ ˯ΎϤϟ΍ ΏϮδϨϣ ΔΑήΘϟ΍ ϞΧ΍Ω ˯ΎϤϟ΍ έΎδϣ ϝϮσ

H A

L

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

3

2011

Q A *V V Q t

of soil

K *i * A

ϑήμΘϟ΍ ϝΪόϣ = Q ϥΎϳήδϟ΍ ϩΎΠΗ΍ ϰϠϋ ΔϳΩϮϤόϟ΍ ΔΣΎδϤϟ΍ = A Ϧϣΰϟ΍ = t

Ϧϴόϣ Ϧϣί ϝϼΧ ϩΎϴϤϟ΍ ΔϴϤϛ = V Discharge velocity

ϑήμΘϟ΍ Δϋήγ

ΔΑϮδΤϤϟ΍ Δϋήδϟ΍ ϰϫ ϭ ϪϠϛ ΔΑήΘϟ΍ ωΎτϗ ϝϼΧ ϩΎϴϤϟ΍ Δϋήγ ϰϫ Ϧϣ ϰγέ΍Ω ϥϮϧΎϗ

V K *i Q A *V

K *i * A

ΕΎΒϴΒΤϟ΍ ΔΣΎδϣ ΎϬϴϓ ΎϤΑ ΎϬϠϛ ΔΣΎδϤϟ΍ ϰϫ = A Seepage velocity

ϥΎϳήδϟ΍ Δϋήγ

ςϘϓ ΔΑήΘϟ΍ ΕΎϏ΍ήϓ ϝϼΧ ϩΎϴϤϟ΍ Δϋήγ ϰϫ

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

4

2011

of soil

Q

AV * V S

A *V

VS

A *V AV

V n

VS

K *i n

K

P

*i

KP = coefficient of percolation Av = area of voids

΢ϴηήΘϟ΍ ϞϣΎόϣ ΕΎϏ΍ήϔϟ΍ ΔΣΎδϣ

ΔϳΫΎϔϨϟ΍ ϞϣΎόϣ ΏΎδΣ ΔϳΫΎϔϨϟ΍ ϞϣΎόϣ ΏΎδΤϟ ϕήσ ΙϼΛ ϙΎϨϫ 1- Lab. tests 2- Field test 3- Empirical equations

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

5

2011

of soil

1- Lab. tests: a) Constant Head Test

ΖΑΎΜϟ΍ ςϐπϟ΍ ΔϘϳήσ

coarse soil (Sand, Gravel)

ΔϨθΨϟ΍ ΔΑήΘϠϟ ϡΪΨΘδϳ

Soil

( t ) ϩέ΍ΪϘϣ Ϧϴόϣ Ϧϣί ϰϓ ˯ΎϤϟ΍ Ϧϣ ΔϴϤϛ ϊϴϤΠΗ ϢΘϳ

Q K

h K * *A L V *L h*t* A

V t

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

6

2011

of soil

ήϴϐΘϤϟ΍ ςϐπϟ΍ ΔϘϳήσ

b) Falling Head Test

ΔϤϋΎϨϟ΍ ΔΑήΘϠϟ ϡΪΨΘδϳ

fine soil (silt, clay)

a h1 h2 Soil A

K

L

a * L § h1 · Ln ¨¨ ¸¸ t*A © h2 ¹ Δϴγ΃ήϟ΍ ΔΑϮΒϧϻ΍ ϊτϘϣ ΔΣΎδϣ = a

(ΔϨϴόϟ΍ ωΎϔΗέ΍) ϥΎϳήδϟ΍έΎδϣ ϝϮσ = L (ΔϳΎϬϨϟ΍ ϭ Δϳ΍ΪΒϟ΍ Ϧϣί ϕήϓ) ΔΑήΠΘϟ΍ Ϧϣί = t (ήϴΒϜϟ΍) ΔΑήΠΘϟ΍ Δϳ΍ΪΑ ϲϓ ˯ΎϤϟ΍ ωΎϔΗέ΍ = h1 (ήϴϐμϟ΍) ΔΑήΠΘϟ΍ ΔϳΎϬϧ ϲϓ ˯ΎϤϟ΍ ωΎϔΗ έ΍ = h2

Soil Mechanics (1)

-:ΚϴΣ


Chapter (6)

Hydraulic properties

7

2011

2- Field tests: (in-situ test) a) Unconfined Test

K

(pumping test)

(ήΤϟ΍ ϥΎϳήδϟ΍) ϡϮϜΤϣ ήϴϐϟ΍ ϥΎϳήδϟ΍

§ r2 Q Ln ¨¨ 2 2 S ( h2 h1 ) © r1

b) Confined test

K

of soil

· ¸¸ ¹

(ήΤϟ΍ ήϴϐϟ΍ ϥΎϳήδϟ΍) ϡϮϜΤϣ ϥΎϳήδϟ΍

§ r2 Q Ln ¨¨ 2SD ( h2 h1 ) © r1 Soil Mechanics (1)

· ¸¸ ¹


Chapter (6) 2011

8

Hydraulic properties of soil

ΪΣ΍ϭ ΔψΣϼϣ ήΌΑ ΩϮΟϭ ΔϟΎΣ ϰϓ

ΪΣ΍ϭ ΔψΣϼϣ ήΌΑ ΩϮΟϭ ΔϟΎΣ ϰϓ

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

9

2011

of soil

3- Empirical equations: a) Hazen formula

K

C * ( D10 ) 2

C = Constant (1-10) C=1

ΔΑΎΘĎ&#x;Î? ωώϧ Ď°Ď Ď‹ ΪϤÎ˜ĎŒĎł

for sand

Permeability of stratified soil

Î•ÎŽĎ˜Î’Ď„Ď&#x;Î? ΓΊΪĎŒÎ˜ĎŁ ΔΑΎΘĎ&#x;Î? Δϳ΍ÎŽĎ”ϧ Ď°Ď˜Ď“ĎľÎ? ĎĽÎŽϳΎδĎ&#x;Î?

a) Horizontal flow

i cons tant

h

q

1m

q1

K1

H1

q2

K2

H2

q3

K3

H3

L

q q1 q2 q3 Keq. * i * H K1* i * H1 K 2 * i * H 2 K 3* i * H 3 Keq. * H K1* H1 K 2 * H 2 K3* H 3 Keq. K X

ÂŚ K1* H1 K 2 * H 2 ....... ÂŚ K * H ÂŚ H1 H 2 .........

ÂŚH Soil Mechanics (1)

H


Chapter (6)

Hydraulic properties

10

2011

b) Vertical flow

of soil

ϲγ΃ΎĎ&#x;Î? ĎĽÎŽϳΎδĎ&#x;Î? V, q = constant K1

H1

K2

H2

K3

H3

h h1 h2 h3 V *H h Â&#x;h H K V * H V * H1 V * H2 V * H3 K K1 K2 K3

V

H K

K*

H1 H2 H3 K1 K2 K3

Keq. K y

Œ H1 H 2 ......... Œ H H § H1 H 2 ¡ ......... ¸ Œ Œ¨Š K1 K 2 K š

Soil Mechanics (1)

H


Soil Mechanics (1) Fff


Chapter (6)

Hydraulic properties

1

2011

of soil

Chapter (6) Hydraulic properties of soil ΔΑήΘϠϟ ΔϴϜϴϟϭέΪϴϬϟ΍ ι΍ϮΨϟ΍ ΎϬϟϼΧ Ϧϣ ˯ΎϤϟ΍ έϭήϣ ˯ΎϨΛ΍ ΔΑήΘϟ΍ ϙϮϠγ Δγ΍έΩ Ϯϫ ϰϫ ˯΍ΰΟ΍ ΙϼΛ Δγ΍έΩ ϢΘϳ ϭ

Geo-static stress

Permeability

Flow net

νέϵ΍ ϥίϭ Ϧϣ ΞΗΎϨϟ΍ ΩΎϬΟϵ΍

ΔϳΫΎϔϨϟ΍

ϥΎϳήδϟ΍ ΔϜΒη

ϥΎϳήδϟ΍ ΔϜΒη

3) Flow net

Flow channel

Flow lines Equipotent lines

Field

Drop head

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2

2011

of soil

ϞΧ΍Ω ˯ΎϤϟ΍ ϥΎϳήγ Ϧϋ ήϴΒόΘϠϟ ΔϟΩΎόϣ Laplace ϢϟΎόϟ΍ ϊοϭ

w 2h w 2 h ΔΑήΘϟ΍ 2 wx wz 2

0 .0

Laplace ΔϟΩΎόϤϟ ϰγΪϨϫ ϞϴΜϤΗ Ϧϋ ΓέΎΒϋ ϰϫ : ϥΎϳήδϟ΍ ΔϜΒη ΔΑήΘϟ΍ ϞΧ΍Ω ˯ΎϤϟ΍ ϥΎϳήγ Ϧϋ ήΒόΗ ϰΘϟ΍ϭ Flow lines: ϥΎϳήδϟ΍ ρϮτΧ ΔΑήΘϟ΍ ϞΧ΍Ω ˯ΎϤϟ΍ έΎδϣ Ϧϋ ήΒόΗ ρϮτΧ ϰϫ Flow channel: ϥΎϳήδϟ΍ ΓΎϨϗ ϦϴϴϟΎΘΘϣ ϥΎϳήγ ϲτΧ ϦϴΑ ΓέϮμΤϤϟ΍ ΔϘτϨϤϟ΍ ϰϫ Equipotent lines:(ςϐπϟ΍) ΪϬΠϟ΍ ϯϭΎδΗ ρϮτΧ ςϐπϟ΍ ϰϓ ΔϳϭΎδΘϤϟ΍ ςϘϨϟ΍ ϦϴΑ ϞμΗ ρϮτΧ ϰϫ Drop head:ΪϬΠϟ΍ ϰϓ ΪϘϔϟ΍ ϦϴϴϟΎΘΘϣ ΪϬΟ ϯϭΎδΗ ϲτΧ ϦϴΑ ΓέϮμΤϤϟ΍ ΔϘτϨϤϟ΍ ϰϫ Field:

ϝΎΠϤϟ΍

ϯϭΎδΗ ϲτΧ ϭ ϦϴϴϟΎΘΘϣ ϥΎϳήγ ϲτΧ ϦϴΑ ΓέϮμΤϤϟ΍ ΔϘτϨϤϟ΍ ϰϫ ΎΒϳήϘΗ ϊΑήϣ ϥϮϜϳ ϥ΍ Ϧϣ ΪΑϻϭ ϦϴϴϟΎΘΘϣ ΪϬΟ

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

3

2011

of soil

:ϥΎϳήδϟ΍ ΔϜΒη Ϣγέ Ε΍ϮτΧ ΐγΎϨϣ Ϣγέ αΎϴϘϤΑ Δϟ΄δϤϟ΍ Ϣγέ -˺ .ϥΎϳήδϟ΍ ρϮτΧ Ϣγέ -˻ ΄θϨϤϠϟ ϖλϼϣ ϥϮϜϳ ϥΎϳήγ ςΧ ϝϭ΃ ΓάϔϨϣ ήϴϐϟ΍ ΔϘΒτϠϟ ϖλϼϣ ϥϮϤϳ ϥΎϳήγ ςΧ ήΧ΃ ρϮτΧ 5 Ϧϋ ϞϘϳ ϻ ϥΎϳήδϟ΍ ρϮτΧ ΩΪϋ ΔϳϭΎδΘϣ ϥΎϳήδϟ΍ ρϮτΧ ϦϴΑ ΔϓΎδϤϟ΍ Smooth ˯ΎδϠϣ ρϮτΧ ϥΎϳήδϟ΍ ρϮτΧ ϥϮϜΗ ϥ΃ -

.ΪϬΠϟ΍ ϯϭΎδΗ ρϮτΧ Ϣγέ -˼ (ϲϟΎόϟ΍ ˯ΎϤϟ΍) U.S. ϰϓ νέϼϟ ϖλϼϣ ϥϮϜϳ ΪϬΟ ϯϭΎδΗ ςΧ ϝϭ΃ (ϲσ΍Ϯϟ΍ ˯ΎϤϟ΍) D.S. ϰϓ νέϼϟ ϖλϼϣ ϥϮϜϳ ΪϬΟ ϯϭΎδΗ ςΧ ήΧ΃ -

Field ϦϳϮϜΘϟ ϥΎϳήδϟ΍ ρϮτΧ ϰϠϋ ΔϳΩϮϤϋ ΪϬΠϟ΍ ϱϭΎδΗ ρϮτΧ Smooth ˯ΎδϠϣ ρϮτΧ ΪϬΠϟ΍ ϯϭΎδΗ ρϮτΧ ϥϮϜΗ ϥ΃ -

H

Example (1)

A

Soil Mechanics (1)

B


Chapter (6) 2011

Hydraulic properties

4

of soil

Nf = No. of flow channel = 4.0 Nd = No. of drop head = 15 Example (2) H

Nf = No. of flow channel = 4.0 Nd = No. of drop head = 13

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

5

2011

of soil

ϥΎϳήδϟ΍ ΔϜΒη ΕΎϣ΍ΪΨΘγ΍

Uses of flow net

ϑήμΘϟ΍ ΏΎδΣ

1) Seepage discharge ( q )

q

Nf K *H * Nd

Ϣγήϟ΍ Ϧϣ

.ϰσ΍Ϯϟ΍ Ϧϋ ϰϟΎόϟ΍ ˯ΎϤϟ΍ ΏϮδϨϣ ϕήϓ = H .ΔϳΫΎϔϨϟ΍ ϞϣΎόϣ = K

φΣϻ

-:ΔΑήΘϟ΍ ωϮϧ ϰτόϣ ϥΎϛ Ϯϟ

.ΕΎϫΎΠΗϻ΍ ϊϴϤΟ ϰϓ ι΍ϮΨϟ΍ βϔϧ ΎϬϟ ΔΑήΗ ϰϫ = Isotropic soil

Kx = Kz

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

6

2011

of soil

ΔϘΑΎδϟ΍ Ε΍ϮτΨϟ΍ βϔϧ ϰϫ Δϟ΄δϤϟ΍ ϞΣ .ΕΎϫΎΠΗϻ΍ ϊϴϤΟ ϰϓ ΎϬλ΍ϮΧ ϒϠΘΨΗ ΔΑήΗ ϰϫ = In-isotropic soil

Kx z Kz -:ϰϠϳ ΎϤϛ ΎϤϫ Ϧϴ΋ΰΟ ϰϓ ϒϠΘΨϳ Δϟ΄δϤϟ΍ ϞΣ In-isotropic soil

q

K

Nf K *H * Nd

Ϣγήϟ΍ ϞΒϗ ϦϜϟ ϭ Δϟ΄δϤϟ΍ Ϣγέ ϢΘϳ ϰϓ ΔϴϘϓϵ΍ ΩΎόΑϵ΍ Ώήο ϢΘϳ

Kx * Kz

Soil Mechanics (1)

Kz Kx


Chapter (6)

Hydraulic properties

7

2011

No. of pumps

N

of soil

(q) ĎŚĎŁ ÎşĎ Î¨Î˜Ď Ď&#x; ΔϣίϟĎ&#x;Î? ΕΎΨĎ€ϤĎ&#x;Î? ΊΪĎ‹

q 1 pump ˜ capacity

2) Seepage pressure ( Ps )

ĎĽÎŽϳΎδĎ&#x;Î? Ď‚Ď?Îż

n ¡ § Ps J w * H * ¨1 ¸ Š Nd š Î”Î‘ĎŽĎ Ď„ϤĎ&#x;Î? Î”Ď„Ď˜ϨĎ&#x;Î? Ď°Î˜ÎŁ drop head Ď°Ď“ ÎŞĎ˜Ď”Ď&#x;Î? ΕÎ?ÎŽĎŁ ΊΪĎ‹ = n

Soil Mechanics (1)


Chapter (6)

8

2011

For Example (1)

Ps A Ps B

Hydraulic properties of soil

5 · § J w * H * ¨1 ¸ 15 ¹ © 12 . 5 · § J w * H * ¨1 ¸ 15 ¹ ©

3) Uplift ϰϠϋϵ ϊϓΪϟ΍ ΓϮϗ ΓΪϋΎϘϟ΍ ΔϳΎϬϧ ϭ Δϳ΍ΪΑ ΪϨϋ seepage pressure ΏΎδΣ ϢΘϳ

Example (1)

2 · § Ps A J w * H * ¨ 1 ¸ © 15 ¹ § 12 · Ps B J w * H * ¨ 1 ¸ © (1)15 ¹ Soil Mechanics


Chapter (6)

Hydraulic properties

9

2011

of soil

W = ΄θϨϤϟ΍ ϥίϭ W = J volume = J A 1

F .O .S

W t 1 . 0 safe F

For Example (2) ΔϳΎϬϧ ϭ Δϳ΍ΪΑ ΪϨϋ seepage pressure ΏΎδΣ ϢΘϳ ΔϓΎδϣ ϰϠϋ D.S. ϰϓ ϊϘϳ ΔΑήΘϟ΍ Ϧϣ ˯ΰΟ ΔϴϧΪόϤϟ΍ ΓέΎΘδϟ΍ Ϧϣ D/2

Soil Mechanics (1)


Chapter (6) 2011

10

Soil Mechanics (1)

Hydraulic properties of soil


Chapter (6)

Hydraulic properties

11

2011

of soil

8 .5 ¡ § H * * 1 ¨ ¸ A w 13 š Š 10 . 5 ¡ § J w * H * ¨1 Ps B ¸ 13 š Š D J sub . * D * W *1 2 § Ps A Ps B ¡ D F ¨ ¸* 2 Š š 2 W t 1 Â&#x; safe F .O . S F Ps

J

ĎĽÎ?έώĎ”Ď&#x;Î?

4) Piping

icr

J sub. Jw

i

'h L min .

'h

Gs 1 1 e

H Â&#x; Nd

ÎŞĎŹÎ Ď&#x;Î? ϲĎ“ ÎŞĎ˜Ď”Ď&#x;Î? έÎ?ÎŞĎ˜ĎŁ

Soil Mechanics (1)


Chapter (6) 2011

Hydraulic properties

12

of soil

ΪϬΟ ϱϭΎδΗ ϰτΧ ήΧ΃ ϦϴΑ Δϴγ΃ήϟ΍ ΔϓΎδϤϟ΍ ϰϫ = Lmin .Ϣγήϟ΍ Ϧϣ αΎϘΗ ϭ Example (1)

Example (2)

i ! icr piping i icr No piping FOS

icr ! 1 .0 i

Soil Mechanics (1)


Chapter (6) 2011

13 Examples

Soil Mechanics (1)

Hydraulic properties of soil


Chapter (6) 2011

14

Soil Mechanics (1)

Hydraulic properties of soil


Chapter (6) 2011

15

Soil Mechanics (1)

Hydraulic properties of soil


Chapter (6) 2011

16

Soil Mechanics (1)

Hydraulic properties of soil


Chapter (6) 2011

17

Soil Mechanics (1)

Hydraulic properties of soil


Chapter (6) 2011

18

Soil Mechanics (1)

Hydraulic properties of soil


Soil Mechanics (1) Fff


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Soil Mechanics (1) Fff


Chapter (6)

Hydraulic properties

2011

of soil

Examples

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

It is required to excavate a trench in the soil formation shown in figure as below. i) Find the depth to which the excavation can be safely carried without causing instability due to uplift of groundwater. ii) Find the lowered groundwater depth, if the excavation is to be extended to 7m

2m 8 m Clay Jsat t/m3

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Chapter (6)

Hydraulic properties

2011

of soil

Soil Mechanics (1)


Soil Mechanics (1) Fff


Chapter (7)

1

2011

Stresses in soil

Chapter (7) Stresses due to loads ϝΎϤΣϵ΍ ΔΠϴΘϧ ΩΎϬΟϻ΍ Types of loads:-

ϝΎϤΣϷ΍ ω΍Ϯϧ΍

1- Point load = Concentrated load

ΰϛήϤϟ΍ ϞϤΤϟ΍

P

2- Line load

ϰτΨϟ΍ ϞϤΤϟ΍

ήϴγ΍Ϯϣ ςΧ ϭ΍ έϮγ Ϧϣ ΞΗΎϧ 3- Strip load

Δϴτϳήη ΔΣΎδϣ ϰϠϋ ϞϤΤϟ΍

Soil Mechanics (1)


Chapter (7)

Stresses in soil

2

2011

ΔΣΎδϣ Ď°Ď Ď‹ ĎžϤΤĎ&#x;Î?

4- Rectangle area

q

1- Point load = Concentrated load

ΰĎ›ΎϤĎ&#x;Î? ĎžϤΤĎ&#x;Î? P

Z

A

Vz

r

P I* 2 Z

I = influence factor

I

3 2S

§ 1 ¨¨ 2 r z 1 ( / ) Š

¡ ¸¸ š

2.5

Soil Mechanics (1)


Chapter (7)

Stresses in soil

3

2011

ϰϨΤϨϣ ĎŚĎŁ ĎŞĎ´Ď Ď‹ Ď?ώΟΤĎ&#x;Î? ĎŚĎœϤϳ Ď­Î?

I

2- Line load

Vz

Ď°Ď„ΨĎ&#x;Î? ĎžϤΤĎ&#x;Î?

q I* Z

q

I = influence factor

I

¡ 2§ 1 ¨¨ ¸ 2 ¸ S Š 1 ( x / z) š

2

Z A

Soil Mechanics (1)

x


Chapter (7)

4

2011

Stresses in soil

ϰϨΤϨϣ Ϧϣ ϪϴϠϋ ϝϮμΤϟ΍ ϦϜϤϳ ϭ΍

I

m = x/z n = y/z ϞϤΤϟ΍ ϝϮσ = y

:φΣϻ ΎϫΪϨϋ ΏΎδΤϟ΍ ΏϮϠτϤϟ΍ ΔτϘϨϟ΍ Ϧϣ ΔϴϘϓϷ΍ ΔϓΎδϤϟ΍ = X, r ϞϤΤϟ΍ ήϴΛ΄Η ϥΎϜϣ ϭ ΎϫΪϨϋ ΏΎδΤϟ΍ ΏϮϠτϤϟ΍ ΔτϘϨϟ΍ Ϧϣ Δϴγ΃ήϟ΍ ΔϓΎδϤϟ΍ = Z ϞϤΤϟ΍ ήϴΛ΄Η ϥΎϜϣ ϭ

Soil Mechanics (1)


Chapter (7)

Stresses in soil

5

2011

Example: For the shown system of loads determine the stresses at point (A) P3, P4

20 t/m P1, P2 4.0

3.0 Elev.

5.0 A P4 = 50

P2 = 70 3.0

Plan

P1 = 80

P3 = 60

Solution ϝΎϤΣϵ΍ Ϧϣ ϦϴϋϮϧ Ϧϣ ϥϮϜΘΗ Δϟ΄δϤϟ΍ ϥ΍ φΣϻ ΍ΪΣ ϰϠϋ ωϮϧ Ϟϛ ΏΎδΣ ϢΘϳ ϚϟΫ ΪόΑ ΩΎϬΟϻ΍ ϊϤΟ ϢΘϳ ϭ

Soil Mechanics (1)


Chapter (7)

Stresses in soil

6

2011

1- Point load: load

r

Z

(r/Z)2

80 70 60 50

0 3 4 5

5 5 8 8

0 0.478 0.36 0.25 0.39

I

P/Z2

Vz

6 2- Line load: X = 4.0 m Z = 5.0 m

· 2§ 1 ¨¨ ¸ I 2¸ S © 1 (x / z) ¹

Vz

q I* Z

2

· 2§ 1 ¨¨ ¸ 2¸ S © 1 (4 / 5) ¹

20 0.236 * 5

Total stress = Vz + 6

Soil Mechanics (1)

2

0.236

0.95


Chapter (7) 2011

7

Stresses in soil

ΰϛήϤϟ΍ ϞϤΤϟ΍ Ϟϔγ΃ ΩΎϬΟϷ΍ ϊϳίϮΗ ϝΎϜη΃

Soil Mechanics (1)


Chapter (7)

Stresses in soil

8

2011

ϪϠϴτΘδϤϟ΍ ΔΣΎδϤϟ΍

3- Rectangle area

ϕήσ ΙϼΜΑ ΩΎϬΟϻ΍ ϊϳίϮΗ ϢΘϳ a) Approximate method Δϳή΋΍Ϊϟ΍ϭ ΔόΑήϤϟ΍ϭ ΔϠϴτΘδϤϟ΍ ΔΣΎδϤϠϟ ϡΪΨΘδΗ q

Z 'V Z/2

L

Z/2

ϲγ΃έ ˻ : ϰϘϓ΍ ˺ ϞϴϤΑ ΩΎϬΟϻ΍ ϊϳίϮΗ ϢΘϳ

q * B * L 'V * (B z)(L z) ϕϮϓ ϲϟ΍ ΔΣΎδϤϟ΍

'V

q*B*L (B z)(L z)

ΖΤΗ ϲϟ΍ ΔΣΎδϤϟ΍

Soil Mechanics (1)


Chapter (7)

9

2011

q* 'V

Stresses in soil

S 4

( D)2

'V *

S 4

( D z)2

( D) 2 q ( D z)2

b) Loaded rectangular area ĎŞĎ Ď¤Î¤Ď¤Ď&#x;Î? ΔΣΎδϤĎ&#x;Î? ĎĽÎŽĎ›έÎ? ĎŚĎŁ ĎŚĎ›έ ĎžĎ”ÎłÎ? ΊÎŽĎŹÎ&#x;ĎťÎ? Î?ÎŽδΤĎ&#x; ϥΪΨΘδΗ ĎžϤΤĎ&#x;ΎΑ

VA q*I

Chart ĎŚĎŁ ϪΑΎδΣ ϢÎ˜Ďł

Soil Mechanics (1)


Chapter (7)

Stresses in soil

10

2011

˰Α ϰϨΤϨϤϟ΍ ϞΧΪϧ

n m

B Z L Z

ϞϤΤϟ΍ ϥΎϜϣ ϭ ΔτϘϨϟ΍ Ϧϣ Δϴγ΃ήϟ΍ ΔϓΎδϤϟ΍ = Z ϞϤΤϠϟ ήϴϐμϟ΍ ϝϮτϟ΍ = B ϞϤΤϠϟ ήϴΒϜϟ΍ ϝϮτϟ΍ = L

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil

11

:φΣϻ ΔΣΎδϤϟ΍ ϞΧ΍Ω ϊϘΗ ΔτϘϨϟ΍ ΖϧΎϛ ΍Ϋ΍ ϰϓ (A) ϥϮϜΗ Ϫϴϓ ˯ΰΟ Ϟϛ ˯΍ΰΟ΍ ϰϟ΍ ϞϴτΘδϤϟ΍ ϢϴδϘΗ ϢΘϳ ϪϧΎϛέ΃ Ϧϣ Ϧϛέ

A

V A q*(I1 I2 I3 I4 ) ΔΣΎδϤϟ΍ ΝέΎΧ ϊϘΗ ΔτϘϨϟ΍ ΖϧΎϛ ΍Ϋ΍

V A q * I( A286) I( A176) I( A253) I( A143)

Soil Mechanics (1)


Chapter (7)

Stresses in soil

12

2011

c) Newmark chart

ϙέΎϣϮϴϧ

chart ϡ΍ΪΨΘγΎΑ ϞϜη ϱϵ ϡΪΨΘδΗ

Newmark chart

ϙϮϠΑ

Soil Mechanics (1)


Chapter (7)

Stresses in soil

13

2011

ϞΤϟ΍ Ε΍ϮτΧ chart ˰ϟ΍ ϰϠϋ ΩϮΟϮϤϟ΍ ΓήτδϤϟΎΑ AB ςΨϟ΍ ϝϮσ αΎϴϗ -˺ ΚϴΣ Ϣγήϟ΍ αΎϴϘϣ ΪϳΪΤΗ -˻

AB ( cm )

Z (m )

ϩΎτόϤϟ΍ ϪϤγήϟ΍ Ϧϣ αΎϘϳ Ϣγήϟ΍ αΎϴϘϤΑ ΎϬΘΠϴΘϧ ΩΎϬΟϵ΍ ΏΎδΣ ΏϮϠτϤϟ΍ ΔΣΎδϤϟ΍ Ϣγέ -˼ ΏϮϠτϤϟ΍ ΔτϘϨϟ΍ ϥϮϜΗ ΚϴΤΑ chart ˰ϟ΍ ϰϠϋ ϪϤγήϟ΍ ϊοϭ ϢΘϳ -˽ ή΋΍ϭΪϟ΍ ΰϛήϣ ϰϓ ΎϫΪϨϋ ΩΎϬΟϵ΍ ΏΎδΣ (N) ΔΣΎδϤϟ΍ ϞΧ΍Ω ΓΩϮΟϮϤϟ΍ ΕΎϛϮϠΒϟ΍ ΩΪϋ ΪϳΪΤΗ -˾

N = 38

Soil Mechanics (1)


Chapter (7)

Stresses in soil

14

2011

ΩΎϬΟϹ΍ ΏΎδΣ -˿

V

0.005 * N * q

ϩΎτόϤϟ΍ ΔΣΎδϤϟ΍ Ϟϔγ΃ ήΛΆϤϟ΍ ΩΎϬΟϹ΍ P

q

ΰϛήϣ ϞϤΣ ϲτόϣ ϥΎϛ ΍Ϋ·

P L*B ϦϴΘΣΎδϣ ΩϮΟϭ ΔϟΎΣ ϰϓ

q1

q2

N1

N2

V 0.005* (N1 * q1 N2 * q2 ) ϰϟϭϷ΍ ΔΣΎδϤϟ΍ ϞΧ΍Ω ΓΩϮΟϮϤϟ΍ ΕΎϛϮϠΒϟ΍ ΩΪϋ = N1 ΔϴϧΎΜϟ΍ ΔΣΎδϤϟ΍ ϞΧ΍Ω ΓΩϮΟϮϤϟ΍ ΕΎϛϮϠΒϟ΍ ΩΪϋ = N2

Soil Mechanics (1)


Chapter (7)

Stresses in soil

15

2011

Contact pressure

βϣϼΘϟ΍ ςϐο

ΔΑήΘϟ΍ϭ αΎγϷ΍ ϦϴΑ βϣϼΘϟ΍ ΢τγ ϰϠϋ ϲγ΃ήϟ΍ ΩΎϬΟϹ΍ ϰϠϋ ΪϤΘόϳ ϭ ΔΑήΘϟ΍ ωϮϧ -˺ ΔΑήΘϟ΍ Δϧϭήϣ -˻ αΎγϷ΍ Γ˯ΎδΟ -˼

Isobars = Pressure bulbs

ςϐπϟ΍ ϯϭΎδΗ ρϮτΧ

ςϐπϟ΍ ϰϓ ΔϳϭΎδΘϤϟ΍ ςϘϨϟ΍ ϦϴΑ ϞμΗ ρϮτΧ Ϧϋ ΓέΎΒϋ ϰϫ

Soil Mechanics (1)


Chapter (7) 2011

16

Soil Mechanics (1)

Stresses in soil


Soil Mechanics (1) Fff


Chapter (7) 2011

Stresses in soil Ëş

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil Ëť

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil Ëź

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil Ë˝

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil Ëž

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil ˿

Final 2005 Find the stress at point (O)

Z ˰ϟ ϦϴΑϮδϨϣ ΩϮΟϭ φΣϼϧ

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil ̀

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil Ě

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil Ě‚

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil ˺˹

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil ˺˺

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil ˺˻

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil ˺˼

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil ˺˽

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil ˺˾

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil ˺˿

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil ˺̀

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil ˺́

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil ˺̂

Soil Mechanics (1)


Chapter (7) 2011

Stresses in soil ˻˹

Soil Mechanics (1)


Soil Mechanics (1) Fff


Chapter (8)

Consolidation

(1)

2011

Chapter (8) Consolidation ΪϠμΘϟ΍ Compressibility

ΔϴσΎϐπϧϻ΍

a a w w S

S

ϝΎѧѧϤΣϷ΍ ΩϮѧѧΟ ϭ ΔѧѧΠϴΘϧ ϢѧѧΠΤϟ΍ ϲѧѧϓ κϘϨѧѧϟ΍ ϰѧѧϠϋ ΔѧѧΑήΘϟ΍ ΓέΪѧѧϗ ϲѧѧϫ ΔΠϴΘϧ ϢΠΤϟ΍ ϲϓ κϘϨϟ΍ ϥϮϜϳ ϭ ΔϴΟέΎΨϟ΍ (έΩΎϧ ) ΐϠμϟ΍ ˯ΰΠϟ΍ ϢΠΣ ϲϓ κϘϧ -˺ (έΩΎϧ) ˯ΎϤϟ΍ ϢΠΣ ϲϓ κϘϧ -˻ ΔΑήΘϟ΍ Ϧϣ ˯ΎϤϟ΍ ΝϭήΧ -˼ ΔΑήΘϟ΍ Ϧϣ ˯΍ϮϬϟ΍ ΝϭήΧ -˽

Soil Mechanics (1)


Chapter (8)

Consolidation

(2)

2011

ΪϠμΘϟ΍

Consolidation

w

S

w

S

ΖѧΤΗ ρΎϐѧπϧϻ΍ ϰѧϠϋ ΔόΒѧθϤϟ΍ ΔѧϴϨϴτϟ΍ ΔѧΑήΘϟ΍ ΓέΪѧϗ Ϧϋ ΓέΎΒϋ Ϯϫ ϝϼѧΧ ΔѧΑήΘϟ΍ Ϧѧϣ ˯ΎѧϤϟ΍ ΝϭήѧΧ ΔΠϴΘϧ ϚϟΫ ϭ ΔϴΟέΎΨϟ΍ ϝΎϤΣϷ΍ ήϴΛ΄Η .ΔϨϴόϣ ΔϴϨϣί ΓήΘϓ Consolidation in Lab. ϞϤόϤϟ΍ ϲϓ ΪϠμΘϟ΍ Oedometer ϡ΍ΪΨΘγΎΑ ϞϤόϤϟ΍ ϲϓ ΪϠμΘϟ΍ ϞϤϋ ϢΘϳ

Soil Mechanics (1)


Chapter (8)

Consolidation

(3)

2011

V Loading plate

Dial gauge

2 cm

Soil

7.5 cm

ring Porous plate

Tank

ΔΑήΠΘϟ΍ Ε΍ϮτΧ ϞϜθϟΎΑ ΎϤϛ ΎϫΩΎόΑ΃ ΔΑήΘϟ΍ Ϧϣ ΔϠϘϠϘϣ ήϴϏ ΔϨϴϋ ΰϴϬΠΗ ϢΘϳ -˺ ˯ΎϤϟΎΑ ΎϣΎϤΗ ΓέϮϤϐϣ ϥϮϜΗ ρήθΑ ίΎϬΠϟ΍ ϲϓ ΔϨϴόϟ΍ ϊοϭ ϢΘϳ -˻ ˻

Ϣγ/ϢΠϛ ˹̄˻˾ ϩέ΍ΪϘϣ ΩΎϬΟΈΑ ΔϨϴόϟ΍ ϞϴϤΤΗ ϢΘϳ -˼

ϲϟΎΘϟ΍ ϮΤϨϟ΍ ϰϠϋ ΔϋΎγ ˻˽ ϝϼΧ ϢΠΤϟ΍ ϲϓ ήϴϐΘϟ΍ αΎϴϗ ϢΘϳ -˽ (0.5, 1, 2, 4, 8, 15, 30 min., 1, 2, 4, 8, 16, 24 hr) ϥϮϜϳ Γήϣ Ϟϛ ϲϓ ϭ ήΧ΃ ΩΎϬΟ· ϡ΍ΪΨΘγΎΑ ˽ ϭ ˼ ΓϮτΨϟ΍ έ΍ήϜΗ -˾ ˻

Ϣγ/ϢΠϛ ˹̄˻˾ Ύϫέ΍ΪϘϣ ΓΩΎϳΰΑ

(0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75, ………) ΏΎδΤϟ ΕΎϴϨΤϨϣ ΓΪϋ Ϣγέ ϭ ΕΎΑΎδΣ ΓΪϋ ϞϤϋ ϢΘϳ -˿ Compression Characteristics

ρΎϐπϧϻ΍ ΕϼϣΎόϣ

Soil Mechanics (1)


Chapter (8)

Consolidation

(4)

2011

Compression Characteristics (av, mv, E, Cc, Cs)

ρΎϐπϧϻ΍ ΕϼϣΎόϣ ϞϤθΗ ϲΘϟ΍ϭ

1- Coefficient of Compressibility (av) e eo

av

1

'e

'e 'V

2

e1 Vo

V1

'V

V

ΩΎϬΟϹ΍ ϲϓ ήϴϐΘϟ΍ ϰϟ· ΕΎϏ΍ήϔϟ΍ ΔΒδϧ ϲϓ ήϴϐΘϟ΍ ϦϴΑ ΔΒδϨϟ΍ Ϯϫ eo = Δϴ΋΍ΪΘΑϻ΍ ΕΎϏ΍ήϔϟ΍ ΔΒδϧ Vo = ςϘϓ ΔΑήΘϟ΍ ϥίϭ Ϧϣ ΞΗΎϨϟ΍ ϝΎόϔϟ΍ ΩΎϬΟϹ΍

Vo

¦J * h

Chapter (6)

'V ϲΟέΎΨϟ΍ ϞϤΤϟ΍ ΔΠϴΘϧ ΩΎϬΟϹ΍ ϲϓ ΓΩΎϳΰϟ΍

'V

Chapter (7)

Soil Mechanics (1)


Chapter (8)

Consolidation

(5)

2011

2- Coefficient of Volume Change (mv) e eo

1

'e 2

e1 Vo

'V

V

V1

mv

Hv 'V

mv

'e 1 * ' V 1 eo

mv

av 1 eo

Hv

'v Vo

'H Ho

ΊÎŽĎŹÎ&#x;ĎšÎ? ϲĎ“ ÎŽĎ´Ď?ΘĎ&#x;Î? Ď°Ď&#x;· ϰϤΠΤĎ&#x;Î? Ď?ÎŽĎŒĎ”ϧϝÎ? όϴΑ ΔΒδϨĎ&#x;Î? ĎŽĎŤ Hv = volumetric strain ϰϤΠΤĎ&#x;Î? Ď?ÎŽĎŒĎ”ϧϝÎ?

Soil Mechanics (1)

'e 1 eo


Chapter (8)

Consolidation

(6)

2011

3- Constrain Modulus = Compression Modulus e (Ev) eo

1

'e 2

e1 Vo

V1

V

'V

Ev Ev

'V Hv 1 mv

ϰϤΠΤϟ΍ ϝΎόϔϧϻ΍ ϰϟ· ΩΎϬΟϹ΍ ϲϓ ήϴϐΘϟ΍ ϦϴΑ ΔΒδϨϟ΍ Ϯϫ

Soil Mechanics (1)


Chapter (8)

Consolidation

(7)

2011

4- Compression Index (Cc) e eo

1

'e 2

e1

Log Vo Log V1 ' Log V

Cc

'e Log (V 1 ) Log (V 2 )

Cc

0.009( L.L 10)

Log V

ϢΘϳέΎϏϮϟ ϲϓ ήϴϐΘϟ΍ ϲϟ· ΕΎϏ΍ήϔϟ΍ ΔΒδϧ ϲϓ ήϴϐΘϟ΍ ϦϴΑ ΔΒδϨϟ΍ Ϯϫ ΩΎϬΟϹ΍

Soil Mechanics (1)


Chapter (8)

Consolidation

(8)

2011

5- Recompression Index (Cr)

ςϐπϟ΍ ΓΩΎϋ·

= Swelling Index (Cs) = Expansion Index (Ce)

εΎϔΘϧϻ΍ ΩΪϤΘϟ΍

e 12 ςΨϟ΍ Ϟϴϣ Ϯϫ 'e

e1 e2

1 2

Log V1 Log V2

Log V

' Log V

Cs

'e Log (V 1 ) Log (V 2 )

ϢΘϳέΎϏϮϟ ϲϓ ήϴϐΘϟ΍ ϲϟ· ΕΎϏ΍ήϔϟ΍ ΔΒδϧ ϲϓ ήϴϐΘϟ΍ ϦϴΑ ΔΒδϨϟ΍ Ϯϫ Loop ˰ϟ΍ ΔϘτϨϣ ϰϓ ΩΎϬΟϹ΍

Soil Mechanics (1)


Chapter (8)

Consolidation

(9)

2011

Preconsolidation pressure (Max. past stress) Vc , Pc ) ϲοΎϤϟ΍ ϲϓ ΔΑήΘϟ΍ Ϫϟ ΖοήόΗ ΩΎϬΟ· ϲμϗ΃ Ϯϫ e

A

ϲϘϓ΃ ϒμϨϣ αΎϤϣ

Log V

Log Vc

Ε΍ϮτΨϟ΍ (αϮϘΗ ήΒϛ΍ Ε΍Ϋ) A ΔτϘϨϟ΍ ΪϳΪΤΗ -˺ ϰϨΤϨϤϠϟ αΎϤϣ ςΧ ϭ ϲϘϓ΃ ςΧ Ϣγήϧ A ΔτϘϧ Ϧϣ -˻ ϢϬϨϴΑ Δϳϭ΍ΰϟ΍ ϒμϨϧ -˼ ΔτϘϧ ϲϓ ϒμϨϤϟ΍ ϊτϘϴϟ ϰϨΤϨϤϟ΍ ϲϓ ϢϴϘΘδϤϟ΍ ςΨϟ΍ ΪϤϧ -˽ Vc ϰϠϋ ϞμΤϨϟ ϲγ΃έ ϝΰϨϧ ΔϘΑΎδϟ΍ ϊσΎϘΘϟ΍ ΔτϘϧ Ϧϣ -˾

Soil Mechanics (1)


Chapter (8)

Consolidation

(10)

2011

Over consolidation ratio (O.C.R)

Vc O.C.R Vo

ϖΑΎδϟ΍ ΩΎϬΟϹ΍ .......... ...... ϲϟΎΤϟ΍ ΩΎϬΟϹ΍

ϲϓ ϡΪΨΘδϳ ϭ ϲϟΎΤϟ΍ ΩΎϬΟϹ΍ ϰϟ· ϖΑΎδϟ΍ ΩΎϬΟϹ΍ ϦϴΑ ΔΒδϨϟ΍ Ϯϫ ΔϴϨϴτϟ΍ ΔΑήΘϟ΍ ϒϴϨμΗ

O .C . R 1 U .C .C O .C . R 1 N .C .C O .C . R ! 1 O .C .C 1- Under consolidation clay (U.C.C)

O .C . R 1 Vc Vo 2- Normal consolidation clay (N.C.C)

O .C . R

Vc

1

Vo

3- Over consolidation clay (O.C.C)

O .C . R ! 1 Vc !Vo Soil Mechanics (1)


Soil Mechanics (1) Fff


Chapter (8)

Consolidation

(1)

2011

Final ËłSettlement ('H Gf

q

ϲ΋ΎϏϨĎ&#x;Î? Ď ĎŽÎ’ĎŹĎ&#x;Î?

L h

J

H

J eo

Z 'V

Clay

L+Z ϲ΋ΎϏϨĎ&#x;Î? Ď ĎŽÎ’ĎŹĎ&#x;Î? Î?ÎŽδΤĎ&#x; όϴϧÎ?ĎŽĎ— ΓΪϋ ϙΎϨύ

'H 'e 1) H 1 e 2 )G f ' H mv * ' V * H 3 )G f

'H

1 * 'V * H Ev Cc , eo Ď°Ď„ĎŒĎŁ ĎĽÎŽĎ› Î?΍·

O.C .R 1.0 4 )G f

§ V o 'V Cc * H * Log ¨¨ 1 eo Š Vo Soil Mechanics (1)

Sand

¡ ¸¸ š


Chapter (8)

(2)

2011

Consolidation

Cs , Vc Ď°Ď„ĎŒĎŁ ĎĽÎŽĎ› Î?΍·

O.C .R ! 1.0 V c ! V o 'V 5)G f

§ V o 'V Cs * H * Log ¨¨ 1 eo Š Vo

¡ ¸¸ š

V c V o 'V § V 'V ¡ Cs §V ¡ Cc ¸¸ * H * Log¨¨ o * H * Log¨¨ c ¸¸ 1 eo Š V c š 1 eo Š Vo š

Gf

H = ĎžϤΤĎ&#x;ΎΑ ΓΪϏΠϤĎ&#x;Î? Clay Ë°Ď&#x;Î? Î”Ď˜Î’Ďƒ ĎšϤγ

Vo

ÂŚ J * h Â&#x;Â&#x; Chapter(6)

Clay Ë°Ď&#x;Î? Î”Ď˜Î’Ďƒ Ď’ÎźÎ˜Ϩϣ Ď°Î˜ÎŁ νέϡÎ? ΢Ď„Îł ĎŚĎŁ Overburden pressure ϰϤδΗ Ď­

'V Â&#x;Â&#x; Chapter(7) Clay Ë°Ď&#x;Î? Ď’ÎźÎ˜Ϩϣ Ď°Î˜ÎŁ ĎžϤΤĎ&#x;Î? ĎŚĎŁ ΞΗΎϨĎ&#x;Î? ΊÎŽĎŹÎ&#x;ĎšÎ? ϲĎ“ ΓΊÎŽϳΰĎ&#x;Î? Z = Clay Ë°Ď&#x;Î? Ď’ÎźÎ˜Ϩϣ Ď°Î˜ÎŁ ĎžϤΤĎ&#x;Î? ĎĽÎŽĎœĎŁ ĎŚĎŁ Î”Ď´ÎłÎƒÎŽĎ&#x;Î? ΔϓΎδϤĎ&#x;Î?

Soil Mechanics (1)


Chapter (8)

Consolidation

(3)

2011

Degree of Consolidation ( U %) ΪϠμΘϟ΍ ΔΟέΩ ϲ΋ΎϬϨϟ΍ ρϮΒϬϟ΍ ϰϟ· Ϧϣί ϱ΃ ΪϨϋ ρϮΒϬϟ΍ ϦϴΑ ΔΒδϨϟ΍ ϲϫ ϭ΃ ϲ΋΍ΪΘΑϻ΍ ˯ΎϤϟ΍ ςϐο ϰϟ· ˯ΎϤϟ΍ ςϐο ϲϓ ήϴϐΘϟ΍ ϦϴΑ ΔΒδϨϟ΍ ϲϫ νϭήϔϟ΍ ξόΑ ΎϬϟ ϭ ϪΑΎδΤϟ Δϳήψϧ Terzaghi ϢϟΎόϟ΍ ϡΪϗ ΪϘϟ ϭ Terzaghi Assumptions ΔόΒθϣ ϭ ΔδϧΎΠΘϣ ΔΑήΘϟ΍ ρΎϐπϧϼϟ ΔϠΑΎϗ ήϴϏ ˯ΎϤϟ΍ ϭ ΔΑήΘϟ΍ ΕΎΒϴΒΣ Darcy ϥϮϧΎϗ ϖϴΒτΗ ΖΑΎΛ ΔϳΫΎϔϨϟ΍ ϞϣΎόϣ ΪΣ΍ϭ ϩΎΠΗ΍ ϲϓ ςϐπϟ΍ ϭ ΔϋϮϨϤϣ ΔϴϘϓϷ΍ ΔϛήΤϟ΍ ϲγ΃ήϟ΍ ϩΎΠΗϻ΍ ϲϓ ˯ΎϤϟ΍ ΝϭήΧ

Soil Mechanics (1)


Chapter (8)

Consolidation

(4)

2011

Gt U% Gf Uo Ut U% Uo Uo = 'V at time = zero

U%

'V U t 'V

G t = Ϧϴόϣ Ϧϣί ΪϨϋ ρϮΒϬϟ΍ G f =

ϲ΋ΎϬϨϟ΍ ρϮΒϬϟ΍

U o = Jw hw ϲ΋΍ΪΘΑϻ΍ ˯ΎϤϟ΍ ςϐο U f =

Ϧϴόϣ Ϧϣί ΪϨϋ ˯ΎϤϟ΍ ςϐο Ϧϴόϣ Ϧϣί ΪϨϋ ρϮΒϬϟ΍ ΏΎδΤϟ

Gt U % *G f U% ΏΎδΣ ϲϫ ΔϠϜθϤϟ΍

Soil Mechanics (1)


Chapter (8)

(5)

2011

Consolidation

U % ΏΎδΤϟ ϲϫ ΕϻΩΎόϣ ϝϼΧ Ϧϣ

TV TV

S

U % 2 U % 52.6%

4 1.781 0.933Log 100 U % U % ! 52.6% U% , TV ϦϴΑ ΔϗϼόϠϟ ϰϨΤϨϣ ϦϜϤϳ ϭ΃

ϻϭ΃ TV ΏΎδΣ Ϧϣ ΪΑϻ U% ΏΎδΣ ϦϜϤϳ ϰΘΣ

TV

CV *t 2 d

Soil Mechanics (1)


Chapter (8)

Consolidation

(6)

2011

7 V = Time factor Ϧϣΰϟ΍ ϰϠϋ ΪϤΘόϳ ϞϣΎόϣ

C V = Coeff. of consolidation ΪϠμΘϟ΍ ϞϣΎόϣ

t = time ΪϠμΘϟ΍ ϩΪϨϋ ΏΎδΣ ΏϮϠτϤϟ΍ Ϧϣΰϟ΍

d = effective depth ΝϭήΨϟ΍ ˯ΎϨΛ΃ ˯ΎϤϟ΍ έΎδϣ ϝϮσ Double drainage = two way drainage ϦϴΘϬΟ Ϧϣ ϑήλ Sand

d

H 2

Clay

H

Sand

Single drainage = One way drainage ΓΪΣ΍ϭ ΔϬΟ Ϧϣ ϑήλ Sand

d

H Clay Rock

Soil Mechanics (1)

H


Chapter (8)

Consolidation

(7)

2011

Cv ΏΎδΣ Coefficient of Consolidation ΪϠμΘϟ΍ ϞϣΎόϣ ϦϴΘϘϳήτΑ ϞϤόϤϟ΍ Ϧϣ ϪϴϠϋ ϝϮμΤϟ΍ ϢΘϳ 1- Cassagrand method (Log time method) 2- Taylor method (Root time method) 1- Cassagrand method (Log time method) U% = 50 % ΪϨϋ Cv ΏΎδΤΑ ϡϮϘϳ Tv = 0.197

At U% = 50 %

0.197

H H0

A

ϰϨΤϨϤϟ΍ Ϧϣ t50 ΐδΤϧ ϡίϻ

H50

H100

CV * t50 d2

B t1 4t1

Soil Mechanics (1)


Chapter (8) 2011

Consolidation

(8)

Ε΍ϮτΨϟ΍ (αϮϘΗ ήΒϛ΍ Ε΍Ϋ ) A ΔτϘϧ ΪϳΪΤΗ -˺ t1 Ϧϣΰϟ΍ ϰϠϋ ϞμΤϨϟ ϲγ΃έ ϝΰϨϧ A ΔτϘϧ Ϧϣ -˻ 4 t1 ϩέ΍ΪϘϣ Ϧϣί ϥΎϜϣ ΪϳΪΤΗ -˼ ϰϠϋ ϝϮμΤϠϟ ϰϠϋ΃ ϲϟ· έήϜΗ ϭ X Δϴγ΃ήϟ΍ ΔϓΎδϤϟ΍ ΪϳΪΤΗ -˽ Ho Δϳ΍ΪΒϟ΍ ϲϓ Γ˯΍ήϘϟ΍ ϦϴτΨϟ΍ ΪϤΑ ϚϟΫ ϭ B ΔτϘϧ ϰϠϋ ϝϮμΤϟ΍ -˾ H100 ΔϳΎϬϨϟ΍ ϲϓ Γ˯΍ήϘϟ΍ ϰϠϋ ϞμΤϧ B ΔτϘϧ Ϧϣ -˿ H50 ϰϠϋ ϞμΤϨϟ Ho , H100 ϦϴΑ ΔϓΎδϤϟ΍ ϒμϨϧ -̀ t50 ϰϠϋ ϞμΤϨϟ ϰϘϓ΍ ϝΰϨϧ H50 Ϧϣ -́ Cv ΏΎδΤϟ ϥϮϧΎϘϟ΍ ϰϓ ϖΒτϧ -̂ 2- Taylor method (Root time method) U% = 90 % ΪϨϋ Cv ΏΎδΤΑ ϡϮϘϳ At U% = 90 %

Tv = 0.848

0.848

CV * t90 d2

ϰϨΤϨϤϟ΍ Ϧϣ t90 ΐδΤϧ ϡίϻ

Soil Mechanics (1)


Chapter (8) 2011

Consolidation

(9)

H H0

A B

Ε΍ϮτΨϟ΍ ϭ Ho ΪϨϋ ϲγ΃ήϟ΍ έϮΤϤϟ΍ ϊτϘϴϟ ϢϴϘΘδϤϟ΍ ςΨϟ΍ ΪϤϧ -˺ A ΪϨϋ ϲϘϓϷ΍ έϮΤϤϟ΍ L ΔϓΎδϤϟ΍ ΪϳΪΤΗ -˻ 1.15 L ΪόΑ ϰϠϋ ϥϮϜΗ ϲΘϟ΍ ϭ B ΔτϘϧ ΪϳΪΤΗ -˼ ϰϓ ϰϨΤϨϤϟ΍ ϊτϘϴϟ H50 ΔτϘϧ ϭ B ΔτϘϧ ϦϴΑ ςΨϟ΍ Ϟμϧ -˽ t90 ϰϠϋ ϞμΤϨϟ ϲγ΃έ ϝΰϨϧ ΎϬϨϣ ΔτϘϧ Cv ΏΎδΤϟ ϥϮϧΎϘϟ΍ ϰϓ ϖΒτϧ -˾

Soil Mechanics (1)


Chapter (8)

Consolidation

(10)

2011

Field curves

ϊϗϮϤϟ΍ ΕΎϴϨΤϨϣ

ϊѧѧϗϮϤϟ΍ ΕΎѧѧϴϨΤϨϣ Ϧѧѧϋ ήѧѧΒόΘϟ ϞѧѧϤόϤϟΎΑ ΪϠѧѧμΘϟ΍ ΕΎѧѧϴϨΤϨϣ ΢ϴΤѧѧμΗ ϲѧѧϫ ΄ѧѧτΨϟ΍ ΍άѧѧϫϭ .ϊѧѧϗϮϤϟ΍ ϲѧѧϓ ΏέΎѧѧΠΗ Ϧѧѧϣ ΎѧѧϬϴϠϋ ϝϮѧѧμΤϟ΍ ΐόѧѧμϳ ϲѧѧΘϟ΍ ϊѧϗϮϤϟ΍ ϲѧϓ ΔѧϨϴόϟ΍ ϕϮѧϓ ΔѧΑήΘϟ΍ ϥίϭ Ϧѧϣ ΔΠΗΎϧ ϝΎϤΣ΃ ΩϮΟϭ Ϧϣ ΞΗΎϧ .ϞϤόϤϟ΍ ϲϓ ΓΩϮΟϮϣ ήϴϏ 1- N.C.C. (Vc Vo

( ςΨϟ΍ Ϊϣ – ϒμϨϣ – αΎϤϣ – ϲϘϓ΃ ) ϖΒγ ΎϤϛ Vc ΩΪΣ -˺ ϞϤόϤϟ΍ Ϧϣ eo ΩΪΣ -˻ (eo , Vo ϊσΎϘΗ ) a ΔτϘϨϟ΍ ΪϳΪΤΗ -˼ f ϰϠϋ ϝϮμΤϠϟ ϰϨΤϨϤϟ΍ ϰΘΣ ϲϘϓ΃ ϝΰϨϧ 0.42 eo ϥΎϜϣ ΩΪΣ -˽ ϊϗϮϤϟ΍ ϲϨΤϨϣ ϲϠϋ ϞμΤϨϟ eo , a , f ΔτϘϧ ϦϴΑ Ϟμϧ -˾

Soil Mechanics (1)


Chapter (8)

Consolidation

(11)

2011

2- O.C.C. (Vc ! Vo

2 1

Vo ΩΪΣ -˺ ϞϤόϤϟ΍ Ϧϣ eo ΩΪΣ -˻ eo , Vo ϡ΍ΪΨΘγΎΑ b ΔτϘϨϟ΍ ΪϳΪΤΗ -˼ ( ςΨϟ΍ Ϊϣ – ϒμϨϣ – αΎϤϣ – ϲϘϓ΃ ) ϖΒγ ΎϤϛ Vc ΩΪΣ -˽ a ϰϓ Vc Ϧϣ ϲγ΃ήϟ΍ ϊτϘϴϟ 12 ςΨϠϟ ϱί΍Ϯϣ Ϣγήϧ b ΔτϘϧ Ϧϣ -˾ f ϰϠϋ ϝϮμΤϠϟ ϰϨΤϨϤϟ΍ ϰΘΣ ϲϘϓ΃ ϝΰϨϧ 0.42 eo ϥΎϜϣ ΩΪΣ -˿ ϊϗϮϤϟ΍ ϲϨΤϨϣ ϲϠϋ ϞμΤϨϟ eo , a , b , f ΔτϘϧ ϦϴΑ Ϟμϧ -̀

Soil Mechanics (1)


Chapter (8)

Consolidation

(12)

2011

3- U.C.C. (Vc Vo

( ςΨϟ΍ Ϊϣ – ϒμϨϣ – αΎϤϣ – ϲϘϓ΃ ) ϖΒγ ΎϤϛ Vc ΩΪΣ -˺ ϞϤόϤϟ΍ Ϧϣ eo ΩΪΣ -˻ (eo , Vo ϊσΎϘΗ ) b ΔτϘϨϟ΍ ΪϳΪΤΗ -˼ ϲϨΤϨϤϟ΍ ϊϣ Vo ϊσΎϘΗ a ΔτϘϧ ΪϳΪΤΗ -˽ f ϰϠϋ ϝϮμΤϠϟ ϰϨΤϨϤϟ΍ ϰΘΣ ϲϘϓ΃ ϝΰϨϧ 0.42 eo ϥΎϜϣ ΩΪΣ -˾ ϊϗϮϤϟ΍ ϲϨΤϨϣ ϲϠϋ ϞμΤϨϟ eo , a , b , f ΔτϘϧ ϦϴΑ Ϟμϧ -˿

Soil Mechanics (1)


Chapter (8)

Consolidation

(13)

2011

Isochrones

q q

U Pore water pressure

V

u

V

Effective stress

ϲΟέΎΨϟ΍ ϞϤΤϟ΍ ΔϣϭΎϘϤΑ ΎϬΑ ΩϮΟϮϤϟ΍ ˯ΎϤϟ΍ ϭ ΔΑήΘϟ΍ ΕΎΒϴΒΣ ϡϮϘΗ ΔΑήΘϟ΍ Ϧϣ ˯ΎϤϟ΍ ΝήΨΗ Ϧϣΰϟ΍ έϭήϣ ϊϣ ϦϜϟϭ :Isochrones effective stress, pore water pressure ϦϴΑ Δϗϼόϟ΍ ΢οϮϳ Ϣγέ ϲϫ ϝΎόϔϟ΍ ςϐπϟ΍ Ϊϳΰϳ ϭ ˯ΎϤϟ΍ ςϐο ϞϘϳ ΎϬϴϓ ϲΘϟ΍ ϭ ΔϔϠΘΨϣ ΔϨϣί΃ ΪϨϋ

Soil Mechanics (1)


Chapter (8)

Consolidation

(14)

2011

ΕΎψΣϼϣ :ΔϳΫΎϔϨϟ΍ ϞϣΎόϣ ΪϳΪΤΗ -˺

K mv *Cv *J w :Field , Lab. ϊϗϮϤϟ΍ ϭ ϞϤόϤϟ΍ ϦϴΑ Δϗϼόϟ΍ -˻ ΔΑήΘϠϟ ΓΰϴϤϣ Δϔλ ΎϬϧϷ ΔΘΑΎΛ ϥϮϜΗ Cv ϥΎϓ Clay βϔϨϟ

CV ( Lab) CV ( Field) § Tv* d ¨¨ © t

2

· ¸¸ ¹Lab

§ Tv* d ¨¨ © t

2

· ¸¸ ¹Field

U% = degree of consolidation ΪϠμΘϟ΍ ΔΟέΩ βϔϧ ΪϨϋ ϲϠϳ ΎϤϛ ϥϮϧΎϘϟ΍ ΢Βμϳ ϭ ΖΑΎΛ Tv ϥϮϜϳ

§d ¨¨ © t

2

· ¸¸ ¹Lab

§d ¨¨ © t

2

· ¸¸ ¹ Field

Soil Mechanics (1)


Chapter (8)

(15)

2011

Consolidation

:ϢΠΤĎ&#x;Î? Ď°Ď“ ÎŽĎ´Ď?ΘĎ&#x;Î? Ď­ Ď ĎŽÎ’ĎŹĎ&#x;Î? όϴΑ Î”Ď—ĎźĎŒĎ&#x;Î? -Ëź

G H

'H 'e 'V H 1 e V :Jsat ĎĄÎŻĎť Gs , Wc ϲĎ„ĎŒĎŁ ĎĽÎŽĎ› Î?ÎŤÎ? -Ë˝

eo

J sat

Gs *Wc Â&#x; Sr 1 Â&#x; sarurated Sr

(Gs Sr * eo )J w Â&#x; Sr 1 1 eo

Soil Mechanics (1)


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Chapter (8)

Consolidation

2011

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Chapter (8)

Consolidation

2011

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Consolidation

2011

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Consolidation

2011

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Consolidation

2011

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Consolidation

2011

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Chapter (8)

Consolidation

2011

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Chapter (8)

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2011

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Chapter (8)

Consolidation

2011

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Chapter (8)

Consolidation

2011

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Chapter (8)

Consolidation

2011

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Chapter (8)

Consolidation

2011

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Chapter (8)

Consolidation

2011

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Chapter (8)

Consolidation

2011

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Chapter (8)

Consolidation

2011

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Consolidation

2011

Soil Mechanics (1)


Chapter (8)

Consolidation

2011

Soil Mechanics (1)


Chapter (8)

Consolidation

2011

Soil Mechanics (1)


Chapter (8)

Consolidation

2011

Soil Mechanics (1)


Chapter (8)

Consolidation

2011

Soil Mechanics (1)


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Consolidation

2011

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Chapter (8)

Consolidation

2011

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Chapter (8)

Consolidation

2011

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Chapter (8)

Consolidation

2011

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Chapter (8)

Consolidation

2011

Soil Mechanics (1)


Chapter (8)

Consolidation

2011

Soil Mechanics (1)


Chapter (8)

Consolidation

2011

Soil Mechanics (1)


Chapter (8)

Consolidation

2011

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Chapter (8)

Consolidation

2011

Soil Mechanics (1)


Chapter (8)

Consolidation

2011

Soil Mechanics (1)


Part(2)

Soil Mechanics (1) Fff


Final Exam

ϯήψϧ

Final Exam ˺

ϯήψϧ

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Soil Mechanics (1)


Part(4)

Soil Mechanics (1) Fff


Final Exam 2011

Final Exam ˺

2011

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Soil Mechanics (1)


Part(1)

Soil Mechanics (1) Fff


Final Exam 2011

Final Exam ˺

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Soil Mechanics (1)


Part(3)

Soil Mechanics (1) Fff


Final Exam 2011

Final Exam ˺

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Soil Mechanics (1)


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