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    Design of Counterfort Retaining Wall (Empty Condition) On D/S)

    Uploaded by

    Jeevan Hingne
    This document provides design details and calculations for a counterfort retaining wall. It includes: - Preliminary dimensions for the wall components - Checks for stability against overturning, sliding, and maximum pressure at the toe - A pressure diagram showing the pressure distribution along the wall - Design parameters and constants used in the calculations like soil properties, concrete grade, steel grade, etc.

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as XLSX, PDF, TXT or read online from Scribd

    Design of Counterfort Retaining Wall (Empty Condition) On D/S)

    Uploaded by

    Jeevan Hingne
    259 views18 pages
    This document provides design details and calculations for a counterfort retaining wall. It includes: - Preliminary dimensions for the wall components - Checks for stability against overturning, sliding, and maximum pressure at the toe - A pressure diagram showing the pressure distribution along the wall - Design parameters and constants used in the calculations like soil properties, concrete grade, steel grade, etc.

    Original Description:

    retert

    Original Title

    Book 345tet

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    This document provides design details and calculations for a counterfort retaining wall. It includes: - Preliminary dimensions for the wall components - Checks for stability against overturning, sliding, and maximum pressure at the toe - A pressure diagram showing the pressure distribution along the wall - Design parameters and constants used in the calculations like soil properties, concrete grade, steel grade, etc.

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as XLSX, PDF, TXT or read online from Scribd
    Download as xlsx, pdf, or txt
    259 views18 pages

    Design of Counterfort Retaining Wall (Empty Condition) On D/S)

    Uploaded by

    Jeevan Hingne
    This document provides design details and calculations for a counterfort retaining wall. It includes: - Preliminary dimensions for the wall components - Checks for stability against overturning, sliding, and maximum pressure at the toe - A pressure diagram showing the pressure distribution along the wall - Design parameters and constants used in the calculations like soil properties, concrete grade, steel grade, etc.

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as XLSX, PDF, TXT or read online from Scribd
    Download as xlsx, pdf, or txt
    of 18
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    The document discusses the design process and calculations for a counterfort retaining wall, including preliminary dimensions, stability checks, and pressure diagrams.

    The steps discussed include determining preliminary dimensions, checking stability against overturning, sliding and pressure at the toe, and creating a pressure diagram.

    The stability is checked against overturning by calculating moments, against sliding by calculating resisting and driving forces, and against maximum pressure at the toe.

    1

    1.0

    Design of Counterfort Retaining wall (Empty condition)on D/S)


    265.80

    264.257
    265.8
    7.91

    10
    10.54

    6.37

    7.92

    10.54
    11.11

    257.89
    2.625

    255.265
    3.20

    3.160

    254.69

    0.575
    A
    2.9

    0.61

    3.16

    6.670
    1.1

    Design Constants
    For M20 grade of concrete and HYSD reinforcement
    cbc

    =7

    = 280/(3* cbc)

    N/mm2

    = 13.3
    st

    = 230.00

    = 1/(1+( st/ m. cbc)


    = 0.29

    = 1-(K/3)
    = 0.90

    = 1/2* cbc*j*K

    N/mm2

    = 0.91

    Height of wall

    = 11.110

    Safe bearing capacity

    = 250

    KN/m2

    Unit weight of soil

    = 18

    KN/m3

    Unit weight of concrete

    = 25

    KN/m3

    Unit weight of PCC

    = 24

    KN/m3

    Coefficient of friction betwwen soil & concrete

    0.58

    Surcharge load assumed


    1.2

    = 10

    KN/m2

    Preliminary Dimensions of the wall components.


    1) Base Width

    = 0.6*H
    = 0.6*11.11
    = 6.670

    2)Toe Projection

    =b *
    Where

    = 1-(p/2.2 r H)
    = 1-(250/2.2*18*11.11)
    = 0.432
    =b *
    = 6.67*0.432
    = 2.9

    3)Clear spacing of counterforts

    = 3.5*(H/r)^1/4
    = 3.5*(11.11/18)^(1/4)

    B)Thickness of counterfort

    = 3.1

    = 0.375

    = 3.48

    C/C spacing of counterfort


    S

    Since the projection of the toe slab is large, provide counterforts over toe slab in front.
    4)Thickness of stem

    A
    B

    W1

    W2

    W3

    = 0.610

    5)Thickness of base slab

    = 0.575

    Effective depth(assuming 12 mm )

    = 519

    mm

    1.3

    Check for Stability of wall


    A) Check against overturning
    B) Check against sliding
    C)Check against max. pressure at toe

    A) Check against overturning


    Description
    1

    Magnituude of load (KN)

    Wt of Stem wall

    Lever arm(point D)

    0.61*10.54*25*3.48
    559.358

    Wt of base slab

    Wt. of earth over heel


    slab

    Wt. of PCC over Toe

    Wt. of counterfort

    1112.78

    5.09

    10619.33

    1.45

    921.90

    4.56

    199.48

    5.09

    559.74

    0.5*3.16*10.54*(25-18)*0.375
    43.71

    3.34

    2.625*2.9*24*3.48
    635.80

    1792.74

    3.16*10.54*18*3.48
    2086.31

    3.21

    0.575*6.67*25*3.48
    333.66675

    Moment(KN

    Surcharge

    3.16*3.48*10
    109.97

    Total

    3768.82

    15205.98

    Horizontal earth pressure on the full height of the retaining wall tend to overturn the wall
    PH

    = 1/2**H2*Ca*S
    = 0.5*18*11.11^2*0.624*3.48
    = 2412.317

    KN

    (Considering Earthquake effect w.r.t IS:1893-1984 )

    Ca=(1+/-v)cos2()/cos.cos2.cos(++)*[1/1+(sin(+).sin(-i-)/cos(-i).cos(++)^0.5]2
    where

    = 0.5*h

    = horizontal seismic coefficient


    = *I*0

    =1

    (Table3)

    =1

    (Table4)

    = 0.040

    (Table2)

    = 1*1*0.04
    = 0.040

    = angle of internal friction of soil


    = 30

    = tan-1 (h/ 1+/- v)

    = 0.5*h

    degrees

    = 0.5*0.04
    = 0.020

    = tan-1(0.04/1+/-0.02)

    (h/ 1+/- v)

    = 0.039

    = 2.247

    = angle which earth face of wall make with ve

    = atan(0/10.54)

    degrees

    =0

    degrees

    = slope of earthfill
    = 26.10

    degrees

    = angle of friction between wall & earthfill


    = 10

    Ca

    degrees

    = 0.624
    Acting at

    = H/3 from A
    = 11.11/3
    = 3.703

    Passive pressure

    = 1/2*Cp*r*H^2*S
    = 0.5*3.93*18*3.2^2*3.48
    = 1260.42

    KN

    Cp=(1+/-)cos2(+)/cos.cos2.cos(+)*[1/1-(sin(+).sin(-i-)/cos(-i).cos(+)^0.5]2
    where

    =0

    degrees

    =0

    degrees

    Cp

    = 3.930
    Acting at

    = H/3
    = 3.2/3
    = 1.07

    1) Moment due to PH

    = 2412.317*3.703
    = 8933.62

    2)Moment due to passive pressure

    = 1260.417*1.07
    = 1344.44

    Overturning Moment

    KN-m

    KN-m

    = 8933.62-1344.445
    = 7589.17
    Factor of Safety

    KN-m

    = MR/Mo
    = 15205.979/7589.171
    = 2.004

    Safe

    B) Check against sliding


    Total horizontal force tending to slide the wall
    = 2412.317
    Total force opposing sliding

    KN

    = * W
    = 0.58*3768.82
    = 2185.913

    Factor of Safety

    KN

    = * W /PH
    = 2185.91/2412.317
    = 0.906

    C)Check against max. pressure at toe

    Safe

    Net moment or algebraic sum of moments about A


    = MR-MO
    = 15205.979-7589.171
    = 7616.81

    KN-m

    Let x be the distance from toe(A) at which the resultant reaction acts
    = MR-MO / W

    = (15205.979-7589.171)/3768.816
    = 2.02
    Eccentricity (e)

    = (b/2)-e
    = 6.67/2-2.02
    = 1.31

    Pmax at toe (A)

    = V/A(1+6*e/b)
    KN/m2

    = 354.29

    Pmin at Heel

    = V/A(1-6*e/b)
    KN/m2

    = -29.55
    The intensity of pressure at junction of stem with toe
    = -29.55+(354.29--29.55)/6.67*(6.67-2.9
    = 187.40

    KN/m2

    The intensity of pressure at junction of stem with heel


    = -29.55+(354.29--29.55)/6.67*(6.67-2.9-0.61
    = 152.30

    1.4

    KN/m2

    Pressure Diagram
    J
    W1

    W3W2

    W1

    0.61

    W3W2

    B
    F
    F0.575

    E
    2.9

    3.2
    -29.55

    354.29

    187.40

    M1

    AB

    W1

    W3W2

    152.30

    B'W4

    KN/m2
    11.11

    10

    11

    12
    Moment(KN-m)

    1792.74

    1112.78

    10619.33

    921.90

    199.48

    559.74
    15205.98

    13

    angle which earth face of wall make with vertical

    angle of friction between wall & earthfill

    14

    15

    (15205.979-7589.171)/3768.816

    55+(354.29--29.55)/6.67*(6.67-2.9-0.61

    16

    Density of soil=
    angle repose=
    Coefficent of active pressure=
    density of concrete
    grade of steel =
    grade of concrete=

    15
    30
    0.333333
    25
    500
    30

    design parameters
    st=
    cbc

    130
    10

    Kn/m2
    degrees
    Kn/m2
    M Pa
    M Pa

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