BANG TINH DAM T CẦU ĐƯỜNG TIẾNG ANHBANG TINH DAM T CẦU ĐƯỜNG TIẾNG ANHBANG TINH DAM T CẦU ĐƯỜNG TIẾNG ANHBANG TINH DAM T CẦU ĐƯỜNG TIẾNG ANHBANG TINH DAM T CẦU ĐƯỜNG TIẾNG ANHBANG TINH DAM T CẦU ĐƯỜNG TIẾNG ANHBANG TINH DAM T CẦU ĐƯỜNG TIẾNG ANH
Trang 105 Calculation Super T Girder L=38.2m_Skew 20.xls【I.General】
SHEET NO : 1 / 1
1 GENERAL
1.1 Design standard
Specification for Bridge Design: 22TCN-272-05
1.2 Material strength and stress limits
1.2.1 Prestressing Steel:
Type of low relaxation strand complies with : ASTM A416, Grade 270
Diameter of tendon = 15.2 mm
Area of tendon = 140mm2
Tensile Strength fpu = 1860 MPa
Yield Strength fpy = 1674 MPa
Modulus of elasticity of strand Ep = 197000Modulus Ratio np = Ep/Ec = 6.00
Stress in the prestressing steel at jacking = 1395 MPa <=> Jacking Force = 195.30 kN 1.2.2 Reinforcing Steel:
Reinf Standart ASTM or TCVN 1651-2008
Yield strength fs = 400MPa
Modulus of elasticity Es = 200000MPa
1.2.3 Concrete:
1.2.3.1 Main Girder:
Specified compressive strength at 28 days f'c = 50MPa
Compressive strength at time of initial prestress f'ci = 42.50 MPa
Modulus of elastic of concrete at release time Eci = 35041 MPa (5.4.2.4-1)
1.2.3.2 Deck Slab:
Specified compressive strength at 28 days f'c = 35MPa
1.3 Design loads and load combination
1.3.1 Dead Loads:
+ Unit weight of reinforcement Concrete = 7850 Kg/m3
+ Unit weight of asphant concrete = 2300 Kg/m3
1.3.2 Live Loads:
+ Live Loads HL93
Trang 205 Calculation Super T Girder L=38.2m_Skew 20.xls【II.Section】
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2 GEOMETRIC PROPERTIES
2.1 Dimension profiles
Distance from bearing to end of girder L1 = 550mm
Distance from bearing to girder notch L2 = 450mm
Length of full section (not inlcude notch) L3 = 1200 mm
Items Notation Sec 1 Sec 2 Sec 3 Sec 4 Sec 5 Sec 6 Sec 7
Effective width of concrete slab B 2350.0 2350 2350 2350 2350 2350 2350
b11 b9
SECTION C-C SECTION A-A
b8
b3 b1
11
4
6 7 8
5 b10
BB
b3 b1
1 3
Trang 305 Calculation Super T Girder L=38.2m_Skew 20.xls【II.Section】
2.2 Section properties in each stage
2.2.1 Stage I&II: Non-composite section
Trang 4-05 Calculation Super T Girder L=38.2m_Skew 20.xls【II.Section】
-Static moment of inertia of
component about bottom s1 (mm3
) 83484375 8.3E+07 8.3E+07 8.3E+07 8.3E+07 8.3E+07 3.7E+07
) 4.13E+08 4.1E+08 4.1E+08 4.1E+08 4.1E+08 -
-s5 (mm3) 10587500 1.1E+07 1.1E+07 1.1E+07 1.1E+07 3.3E+08 2.3E+07
-2.2.1.3 Centroid
of component to neutral axis e2 (mm) -877 -877 -877 -874 -869 896 384
) 22309028 2.2E+07 2.2E+07 2.2E+07 2.2E+07 -
-I10 (mm4) 22851563 2.3E+07 2.3E+07 2.3E+07 2.3E+07 2.3E+07 2E+07
D = 15.2 mm I12 (mm4) 691748.4 691748 691748 628862 518811 518811 0E+00
Sum (a) 1.21E+11 1.2E+11 1.2E+11 1.2E+11 1.2E+11 3.2E+11 3.1E+10
Distance from neutral axis
to top fiber of girder
Distance from neutral axis
to bottom fiber of girder
Trang 505 Calculation Super T Girder L=38.2m_Skew 20.xls【II.Section】
SHEET NO : 4 / 4
b Moment of inertia of components about centroid of section
I1 (mm4
) 3.86E+10 3.9E+10 3.9E+10 3.8E+10 3.8E+10 3.2E+10 7E+09
I2 (mm4) 4.32E+08 4.3E+08 4.3E+08 4.3E+08 4.2E+08 -
-I3 (mm4) 5.13E+09 5.1E+09 5.1E+09 5.1E+09 5E+09 4.3E+09 7.5E+08
I4 (mm4) 1.27E+09 1.3E+09 1.3E+09 1.2E+09 9.2E+08 -
-I5 (mm4) 6.02E+09 6E+09 6E+09 6.1E+09 6.2E+09 1.4E+10 4.6E+08
I12 (mm4) 1.23E+10 1.2E+10 1.2E+10 1.1E+10 8.2E+09 8.2E+09
-Sum (b) 1.61E+11 1.6E+11 1.6E+11 1.6E+11 1.6E+11 1.5E+11 2.7E+10Moment of inertia stage I&II II&II (mm4
) 2.82E+11 2.8E+11 2.8E+11 2.8E+11 2.8E+11 4.7E+11 5.7E+10
2.2.2 Stage III: Composite section
-rectangle h (mm) 195 195 195 195 195 -
-A9 (mm2
) 458250 458250 458250 458250 458250 - Total section area ΣA III (mm2) 1220663 1220663 1220663 1217863 1212963 1668275 897875
Moment of inertia stage I&II II&II (mm4
) 2.82E+11 2.8E+11 2.8E+11 2.8E+11 2.8E+11 4.7E+11 5.7E+10
e(mm) -385 -385 -385 -385 -384 - -
(mm4) 1.13E+11 1.1E+11 1.1E+11 1.1E+11 1.1E+11
-Moment of inertia of K9 I9 (mm4) 1.45E+09 1.5E+09 1.5E+09 1.5E+09 1.5E+09 - -
Distance from K9 to bottom
fiber of girder
Static moment of K9 about
bottom fiber of girder
Distance from neutral axis
to top fiber of girder
Distance from neutral axis
to bottom fiber of girder
Distance from neutral axis
to top fiber of slab
Distance from neutral axis
to center of tendons
Distance from neutral axis
of stage I to stage II
Moment of inertia about
centroid of section at stage
II
Distance from center of K9
to neutral axis of composite
Trang 605 Calculation Super T Girder L=38.2m_Skew 20.xls【III.Tendon】
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3 TENDON ARRANGEMENT
3.1 Input date
Using straight tendons with diameter 15.2 mm <=> A_ten 140.0 mm2
To reduce tensile stress at bearing locations, unbonded tendons are created by using PE tube
Effective length of tendons
+3000+3000
3000 +
70005000
++
+
300030003000+
70005000
++++
50005000
2 4 6 8 10 12
3 5 7 9 11
ROW A - HÀNG A ROW C - HÀNG C ROW D - HÀNG D
Trang 705 Calculation Super T Girder L=38.2m_Skew 20.xls【III.Tendon】
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3.2 Sum of tendons at sections
Section Distance from center of tendons to bottom fiber of girder Distance from center of all tendons ΣA ps (mm 2 )
3.3 Force transfering length & developing length of tendons
Developing length of normal tendon (mm) ld = [0.15fps-0.097fpe]dp = 2535 (5.11.4.2-272-05)Developing length of covered tendon (mm) ld = 2[0.15fps-0.097fpe]dp = 5071 (5.11.4.3-272-05)Group 1: 25 tendons with bond length taken from girder edge 0 mm
Group 2: 2 tendons with bond length taken from girder edge 1000 mm
Group 3: 6 tendons with bond length taken from girder edge 3000 mm
Group 4: 7 tendons with bond length taken from girder edge 5000 mm
Group 5: 4 tendons with bond length taken from girder edge 7000 mm
Prestress of tendons at tension stage - prestress loss due to shrinkage = 1304 MPa
Trang 805 Calculation Super T Girder L=38.2m_Skew 20.xls【III.Tendon】
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3.4 Internal forces due to prestressed tendons at sections
PRESTRESSING FORCE FOR TENDONS
Group number Distance from section to girder notch (mm)
Prestressing moment at tension stage (kN-m)
677.77 677.77 677.77 680.23 685.59 750.67 0.00-866.83 -866.83 -866.83 -864.37 -859.01 -793.93 0.00693.17 693.17 693.17 695.63 700.99 896.07 0.00661.74 661.74 661.74 664.20 830.99 896.07 0.00665.67 665.67 665.67 825.63 830.99 896.07 0.00
Sum of moment (kN-m) -4867.15 -4867.15 -4867.15 -4399.04 -3151.67 -3362.00 0.00 Prestressing moment after all stress losses (kN-m)
Trang 905 Calculation Super T Girder L=38.2m_Skew 20.xls【III.Tendon】
Lực nén trước và sau các mất mát ứng suất Compression forces before and after all prestress loss
P cang cap - P at tension stage
P sau mat mat us - P after all prestress loss
Trang 1005 Calculation Super T Girder L=38.2m_Skew 20.xls【IV.Distribution】
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4 LIVE LOAD DISTRIBUTION FACTOR
4.1 Superstructure profiles
Multiple presence factor (lane factor) m = 0.85 Section 3.6.1.1.2 - 22TCN-272-05)
Width of loaded lane within cantilever slab de = 800mm
Width between top flanges of girder b = 1050 mm
Design for exterior/interior girder ( E/I ) E
4.2 Effective width of girder flange According to Section 4.6.2.6 in 22TCN-272-05)
1/4 Le = 9275 mm bei/2 + 1/8 Le = 5813 mm
12ts + b/2 = 2865 mm bei/2 + 6ts + b/4 = 2607.5 mm
S = 2350 mm bei/2 + wo = 2325 mm
=> bei = 2350 mm => bee = 2325 mm
4.3 Live load distribution factor According to Section 4.6.2.2.2 - 22TCN-272-05)
Applied section according to Table 4.6.2.2.1.1 is typical section c
Moment distribution for interior girders
Shear distribution for interior girder
For >2 loaded lanes:
Shear distribution for exterior girder
For >2 loaded lanes:
gs,E = (0.8 + de/3050)gs,I = 0.808 Table 4.6.2.2.3b-1-22TCN-272-05)
Trang 1105 Calculation Super T Girder L=38.2m_Skew 20.xls【IV.Distribution】
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Reduction of load distribution factor for moment in longitudinal beams
Moment distribution for exterior girder = 0.555
Shear distribution for exterior girder = 0.979
Trang 1205 Calculation Super T Girder L=38.2m_Skew 20.xls【V.Loads】
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5 LOADS AND LOAD COMBINATIONS
5.1 Superstructure profiles
Width of pedestrian path (1 side) 0.000 m
Wearing surface thickness tw = 0.050 m
Multiple presence factor (lane factor) m = 0.850
Weight of precast concrete plate 0.635 kN/m
Asphalt concrete density γw = 22.563 kN/m3
5.2 Dead load on each girder
Stage 1
Dead load of girder 18.698 kN/m = Cross section area x γc
Stage 2
Dead load of concrete slab 11.191 kN/m = W * ts * γc / Nb
Dead load of precast plate 0.635 kN/m
Stage 3
Dead load of parapet 3.850 kN/m
DL of Technical Box 0.000 kN/m
DL of wearing surface 2.143 kN/m = Wl * tw * γw / Nb
LOADS APPLIED ON GIRDERS
P3
P2
Trang 1305 Calculation Super T Girder L=38.2m_Skew 20.xls【V.Loads】
SHEET NO : 2 / 2 Self weight, lane load,
dead load of concrete slab, wearing surface, parapet
Load distribution
5.3 Live loads
Loads induce bending moment
IF = 1+ IM Dist factor (Load x factor) (P x DF x IM)
Loads induce shear
IF = 1+ IM Dist factor
(Load x factor) (P x DF x IM)
Maximum load factor
LC Dead load Live load Lane load Shrink.
STRENGTH-1 1.25 1.25 1.25&1.50 1.75 1.75 0.5
Le
Trang 1405 Calculation Super T Girder L=38.2m_Skew 20.xls【VI.Stress Losses】
∆ fpT : Total stress losses (Mpa)
∆ fpES : Loss due to elastic shortening (Mpa)
∆ fpSR : Loss due to shrinkage (Mpa)
∆ fpCR : Loss due to creep of concrete (Mpa)
∆ fpR2 : Loss due to relaxation of steel after transfer (Mpa)
6.1 Loss due to elastic shortening
Loss due to elastic shortening of each prestressing tendons
∆ fpES = E = Epfcgp/Eci Section 5.9.5.2.3a-1 - 22TCN-272-05) Where:
fcgp
and the selfweight of the member at the sections of maximum moment (Mpa)
Ep = 197000 (MPa) Elastic modulus of prestressing tendon
Eci = 35041 (MPa) Elastic modulus of concrete at transfer
Area of Tensile strength Prestress Totaltendon of tendon at transfer Prestress(m2) (MPa) (MPa) (kN) Sec 1 18.55 44 0.006160 1860 1395 8593
P = (kN) Axial force in tendon at midspan
Mg = (kN.m) Bending moment due to selfweight at midspan
Ag = (m2) Cross section area of girder at midspan
Ig = (m4) Moment of inertia of girder at midspan
y = (m) Distance from neutral axis to bottom fiber of girder
e = (m) Distance from center of tendon to neutral axis
(m) (m) (kN.m) (m2) (m4) (MPa) (MPa) Sec 1 0.823 0.632 3217 0.7624 0.2822 16.222 91.20
Section Length No strands
= Sum of concrete stresses at the center of prestressing tendons due to prestressing force at transfer
Trang 1505 Calculation Super T Girder L=38.2m_Skew 20.xls【VI.Stress Losses】
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6.2 Loss due to creep of concrete
∆ fpCR=12*fcgp-7* ∆ fcdp > 0 Section 5.9.5.4.3-1 - 22TCN-272-05) Where:
fcgp: Stress in concrete at center of tendon at transfer (Mpa)
∆ fcdp: Change of stress in concrete at center of tendon due to permanent loads at each section
taken as ∆ fcdp.
∆ fcdp = Mp-Iie-II/Ig-II+Mp-IIIe-III/Ig-IIIWhere:
Mp: bending moment which changes prestressing stress at center of tendon
due to permanent loads Section e-II e-III Mp-II Mp-III Ig-II Ig-III ∆ fcdp ∆ fpCR
(m) (m) (kN.m) (kN.m) (m4) (m4) (MPa) (MPa) Sec 1 0.632 1.016 2034.69 1031.19 0.2822 0.5839 6.350 150.21
H = 85% Everage annual ambient relative humidity
6.4 Loss due to relaxation and total prestress loss
∆ fpR2 = 30%[138-0.4 ∆ fpES-0.2( ∆ fpSR+ ∆ fpCR)] (MPa) Section 5.9.5.4.4c-1-22TCN-272-05)
30% is reduction factor for relaxation rate (According to ASTM A 416M)
∆ fpT = ∆ fpES + ∆ fpES + ∆ fpCR + ∆ fpCR2
Section ∆ fpES ∆ fpSR ∆ fpCR ∆ fpR2 ∆ fpT fpe check fpe
(MPa) (MPa) (MPa) (MPa) (MPa) (MPa) Sec 1 91.20 29.45 150.21 19.68 290.53 1104.47 OK
Trang 1605 Calculation Super T Girder L=38.2m_Skew 20.xls【VII.Foerces】
Trang 1705 Calculation Super T Girder L=38.2m_Skew 20.xls【VII.Foerces】
Area of influence line (+) Ω7 = 8.246
7.2 Influence lines for shear force
Trang 1805 Calculation Super T Girder L=38.2m_Skew 20.xls【VII.Foerces】
Area of influence line (+) Ω7 = 18.103 (-) Ω7 = -0.003
7.3 Internal forces due to dead loads
Summary table of influence areas
Span length Area of influence line
Trang 1905 Calculation Super T Girder L=38.2m_Skew 20.xls【VII.Foerces】
7.4 Internal forces due to live loads
Applied live loads on girders
P3
P2
P1
P4
P5
A2=4.3
Trang 2005 Calculation Super T Girder L=38.2m_Skew 20.xls【VII.Foerces】
Suddent prestres
s loss
Total pre
force at transfer
Total prestress loss
Total pre
force after all loss
Bending moment due to prestress
at transfer
Bending moment due to prestress after all loss
(m2) (MPa) (MPa) (kN) (MPa) (kN) (kN.m) (kN.m)
Internal forces due to wheel axles x DF x IM
Trang 2105 Calculation Super T Girder L=38.2m_Skew 20.xls【VII.Foerces】
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7.4.4 Load Combinations:
Load combination for Service State
1 Girder selfweight 3217.04 3082.04 2677.04 1848.24 1196.80 546.85 154.192
Stage 2
3 Selfweight of concrete slab 1925.38 1844.59 1602.19 1106.16 716.28 327.29 92.28
4 Selfweight of precast concrete plate 109.31 104.72 90.96 62.80 40.66 18.58 5.24
Stage 3
5 Wearing surface dead load 368.79 353.31 306.89 211.88 137.20 62.69 17.68
6 D.L of parapet & Technical Box 662.40 634.60 551.21 380.56 246.42 112.60 31.75
8 Pedestrian
Sum of all stages 1+2+3 8995.39 8640.27 7519.59 5210.77 3379.80 1546.21 301.13
2
Stage 2
3 Selfweight of concrete slab 0.00 42.52 85.05 135.41 164.50 189.12 202.55
4 Selfweight of precast concrete plate 0.00 2.41 4.83 7.69 9.34 10.74 11.50
Stage 3
6 D.L of parapet & Technical Box 0.00 14.63 29.26 46.59 56.60 65.07 69.69
Trang 2205 Calculation Super T Girder L=38.2m_Skew 20.xls【VII.Foerces】
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Load combination for Strength-I Limit State
1 Girder selfweight 1.25 4021.30 3852.55 3346.30 2310.30 1496.00 683.56 192.742
Sum of all stages 1+2+3 12699.41 12208.47 10638.89 7395.73 4811.05 2236.71 395.50
1 Girder selfweight 1.25 0.00 88.82 177.63 282.81 343.58 395.00 423.052
Trang 2305 Calculation Super T Girder L=38.2m_Skew 20.xls【VII.Foerces】
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Load combination for Fatigue Limit State
Sum of all stages 1+2+3 2034.36 1965.75 1718.48 1200.85 781.83 358.65 0.00
Trang 2405 Calculation Super T Girder L=38.2m_Skew 20.xls【VIII.Resistance】
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8.1 Bending moment resistance
Average stress in prestressing tendons fps = fpu*(1 - k*c/dp) (Section 5.7.3.1.1-1-22TCN-272-05)
(Section 5.7.3.1.1-2-22TCN-272-05)Distance from C.L to compression part c = Aps*fpu + As*fy - A's*f'y - 0.85*β1*f'c*(b-bw)*hf
0.85*b1*f'c*bw + k*Aps*fpu/dp
(Section 5.7.3.1.1-3 - 22TCN-272-05 - Assume equivalent section as T-section)
Ultimate tensile strength of prestressing tendon fpu = 1860 MPa
Yield strength of tensile reinforcing bar fy = 400 MPa
Yield strength of compressive reinforcing bar f'y = 400 MPa
Distance from extreme compression fiber to center of all tendons dp = mm
Bending moment resistance Mr = ϕ*Mn (Section 5.7.3.2.1-1 - 22TCN-272-05)Where:
Resistant factor for bending and tension of prestressed concrete ϕ = 1
Mn = Aps*fps*(dp - a/2) + As*fî*(ds - a/2) - A's*f'y*(d's - a/2) (Section 5.7.3.2.2-1 - 22TCN-272-05)
Distance from extreme compression fiber to center of compression reinforcing barsd's = mm
Distance from extreme compression fiber to center of tensile reinforcing barsds = mm
Bending moment at Strength-I kNm 12699 12208 10639 7396 4811 2237 395