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    Staicase

    Uploaded by

    Alex Macharia
    1) The document provides design parameters and properties for a concrete staircase including dimensions, material properties, and load calculations. 2) Static load analysis calculates total dead and live loads of 6.75 kN/m^2 and 4 kN/m^2 respectively, resulting in a design load of 14.19 kN/m^2. 3) Bending moment calculations for flight and landing result in support and mid-span moments of 30.22 kN-m and 24.73 kN-m requiring longitudinal reinforcement of T12 bars at 150mm spacing.

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    Staicase

    Uploaded by

    Alex Macharia
    22 views4 pages
    1) The document provides design parameters and properties for a concrete staircase including dimensions, material properties, and load calculations. 2) Static load analysis calculates total dead and live loads of 6.75 kN/m^2 and 4 kN/m^2 respectively, resulting in a design load of 14.19 kN/m^2. 3) Bending moment calculations for flight and landing result in support and mid-span moments of 30.22 kN-m and 24.73 kN-m requiring longitudinal reinforcement of T12 bars at 150mm spacing.

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    Original Title

    Staicase(1)

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    1) The document provides design parameters and properties for a concrete staircase including dimensions, material properties, and load calculations. 2) Static load analysis calculates total dead and live loads of 6.75 kN/m^2 and 4 kN/m^2 respectively, resulting in a design load of 14.19 kN/m^2. 3) Bending moment calculations for flight and landing result in support and mid-span moments of 30.22 kN-m and 24.73 kN-m requiring longitudinal reinforcement of T12 bars at 150mm spacing.

    Copyright:

    © All Rights Reserved
    Download as XLSX, PDF, TXT or read online from Scribd
    Download as xlsx, pdf, or txt
    22 views4 pages

    Staicase

    Uploaded by

    Alex Macharia
    1) The document provides design parameters and properties for a concrete staircase including dimensions, material properties, and load calculations. 2) Static load analysis calculates total dead and live loads of 6.75 kN/m^2 and 4 kN/m^2 respectively, resulting in a design load of 14.19 kN/m^2. 3) Bending moment calculations for flight and landing result in support and mid-span moments of 30.22 kN-m and 24.73 kN-m requiring longitudinal reinforcement of T12 bars at 150mm spacing.

    Copyright:

    © All Rights Reserved
    Download as XLSX, PDF, TXT or read online from Scribd
    Download as xlsx, pdf, or txt
    of 4

    DESIGN PROPERTIES AND PARAMETERS

    concrete densiity 25 KN/M3


    Main bar φ 12 Distribution bar φ 10 MM
    -Concrete cover to rebars, c 20 mm
    -Floor - to - floor height 3150 mm
    -Landing slab thickness h 150 mm
    Flight dimensions Waist thickness 175 mm
    treads 300 mm
    raisers 150 mm
    Length of flight 3200 3.2
    Width of landing 1200 1.2
    Concrete compressive strength, fck= 20 4.4
    -Rebar Steel Strength, fyk= 425 N/MM2
    Fli

    STAICASE LOAD ANALYSIS


    Staircase dead loads flight landing
    waist s/w 4.375 3.75
    self weight of steps 1.875 0
    finishes /screeds 0.5 0.5
    6.75 KN/M2 4.25 KN/M2
    total dead loads, Gk
    Variable loads
    Structure utility Staicase 4 KN/M2

    Toaal live load ,Qk 4 KN/M2


    Taking 1m width of staicase 1000 ULS SLS
    Design load F1(FLIGHT) 15.11 10.75
    Design load F1(landing) 11.74 8.25

    AVERAGE LOAD F 14.19 KN/M2 10.06818 KN/M2

    Ultimate bending moment


    Support moment 30.22 KN/M

    NEAR END SPAN MOMENT 24.73 KN/M

    EFFECTIVE DEPTH , d eff


    𝑑𝑒𝑓𝑓 = ℎ − 𝑐 − ∅ ′ 2 149.00 mm

    𝐾 = 𝑀 /𝑏𝑑 ^2 𝑓𝑐k 0.07 no comp reinforcement needed


    LEVER ARM ,Z
    z=d(0.5+(0.25 - k/1.134)^0.5 139.44 mm
    Steel reinforcement requirement
    𝐴𝑠 = 𝑀 /0.87𝑓𝑦𝑘 Z 586.19 mm2
    Min As = 0.15%bd 223.50 mm2
    Max As =4%bd 5960 mm2
    T10@200 200 298 392.5 AREA IS OK
    As pro T12@150 150 753.6 MM2/M AREA IS OK
    Near mid span moment
    𝐾 = 𝑀 /𝑏𝑑 ^2 𝑓𝑐k 0.056 no comp reinforcement needed
    lever arm
    z=d(0.5+(0.25 - k/1.134)^0.5 141.28 141.28 mm
    Steel reinforcement requirement
    𝐴𝑠 = 𝑀 /0.87𝑓𝑦𝑘 Z 473.4 473.4 mm2
    Min As = 0.15%bd
    Max As =4%bd
    As providedT12@150 150 753.60 mm2 CONTINUE
    Distribution steel reinforcement 200 298 mm2
    T10@200 392.5 mm2 CONTINUE
    shear check
    type of support short sapn and continous

    βvx = 0.6
    Ved = 37.467 Kn/m

    Max. design shear resistance VRd, c


    VRd, c = {CRd, c × k × (100 × ρ1 × fck) 1/3 ≥ (Vmin = 0.035 × k1.5 × √fck)}×bwd CRd,
    c = 0.12 0.12
    k = 1+√(200/d) = 2
    ρ1 = Asl/ (bw d) 0.005058

    Vrd 77.3379 Kn/m


    Vmin 65.96511 Kn/m

    Therefore, vRd, c = 77.3379 Kn/m


    The shear strength is satisfactory; no shear reinforcement is required

    deflection check
    Support type = End span of continuous beam or slab
    K = 1.5 Eq. (7.17) σs = (7.3/ 10.1) × (500/1.15) = 313 MPa ≈ 310 MPa assumed in the formul
    289.658915184862

    Tension reinforcement ratio = ρ = 0.505772 50.57718 #REF!


    Reference reinforcement ratio = ρo = 0.447214 e
    Allowable span / eff. depth, L/d ratio 16.58897

    Correcting for As, prov > As, reqd, L/d = 31.02138


    Actual span/Eff. depth, L/d ratio = 29.5302

    Deflection will no exceed the permitted L/250.


    check for cracking
    Maximum spacing of bars in concrete slab is normally restricted to the following;
    NOTE: 3 3h ≤ 400 mm for principal reinforcement
    3.5 h ≤ 450 mm for secondary reinforcement

    138
    190

    The clear distance between bars, 138 & 190mm less than 400 & 450mm respectively
    Hence slab bars spacings are satisfactory with regard to cracking
    m
    m
    m

    ent needed

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