Post on 14-Apr-2018
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RCI Project - Rail Component
Subproject - 1
Bridge No.
DESIGN OF ABUTMENT WALLS
Specification data
Unit Weight of Concrete = 25.00
Unit Weight of Soil = 18.00
Angle of Internal Friction () = 30
Co-eff., Active Earth Press. (Ca) (Weep hole will not be used) = 0.50
Ultimate Strength of Steel (fy) Cube Strength CF for Cylinder = 5.00E+05
Ultimate Strength of Conc. (f'c) 35000 kn/m * 0.800 = 2.80.E+04
Allowable Stress of Steel (fs) 0.40 * fy = 2.00E+05
Allowable Stress of Concrete (fc) 0.40 * f'c = 1.1E+04
Shear Stress, no Web Reinf. (vc) 2.89 * f'c^.5= 4.8E+02
Shear Stress (Punching) 5.25 * f'c^.5= 878
Allowable Bond Stress 113 f'c)^0.5/d = 1.90E+04
(d = Bar Diameter, mm) OR --> = 1103 Kn/m (whic
Modulus, Elasticity of Steel (Es) = 2.00E+08
Modulus, Elasticity of Conc. (Ec) = 2.53E+07
Cover + 1/2 the Bar Diameter = 91
For Above Unit Stresses, n = 7.90
For Above Unit Stresses, k = 0.307
For Above Unit Stresses, j = 0.898
For Above Unit Stresses, R = 1.54E+03
Rail Top Rail Ht. Sleeper Ballast W.C
Design Data 8.919 0.172 0.220 0.300 0.080
Formation Level or Wall Top Level (Rail Level - Rail Ht. - Sleeper Thickness) = 8.147
Wall Bottom Slab Level = 2.147
Bottom of Bearing Level = 6.469
Assumptions
Thickness of Abutment Wall at Top = 500
Thickness of Abutment Wall at Bottom = 1200
Base Slab Thickness Assumed = 1800
Width of the Abutment Wall = 9.200
Height from top of base, h = 6.00
Total Height of the Abutment, H = 7.80
500 mm
8.147 m
//////////////// ////////////////
6.00 m
EL 2.147 1200
1800 mm
ABUTMENT WALL SECTION (Typical)
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DESIGN OF ABUTMENT WALLS
DESIGN LOADS AND MOMENTS (per m length of wall)
Static Earth Pressure in Abutment Wall, EAS = 1/2* *H *CAS = 162.00 kn
And acts at height from base of Abutment Wall, H/3 = 2.00 m
Corresponding Moment = 324.00 kn-m
Dynamic Force Exerted by the Soil Mass, EAE = 1/2**H *CAD = 4.43 kn
And acts at height from base of Abutment Wall, H/2 = 3.00 m
Corresponding Moment = 13.28 kn-m
Pressure due to Dead and Live Load Surcharge
Active Earth Pressure, Rectangular Part, = (S+V)/L*Ca = 65.30 kn/m
Acting at h/2 from section under consideration at base = 3.90 m
Active Earth Pressure, Triangular Part = 53.64 kn/m
Acting at (h-((L-B)/3)) from section under consideration = 3.93 m
Corresponding Moment = 465.66 kn-m
Longitudinal Forces on Abutment (With Fixed Bearing) Span : 25mLongitudinal Force, Coefficient 0.50 84.00 Ton = 412 kn
(As per U IC Code 774 - 3R, @nd editi on, October 2001, Page 16, Wi th CWR)
Force per metre Width of Abutment = 44.76 kn/m width
And acts at the Bearing Level with Moment Arm = 4.32 m
Corresponding Moment = 193.44 kn-m
DESIGN OF ABUTMENT WALLS
DESIGN LOADS, MOMENTS AND SHEARS
H = Height of Stem = 6.00 m
V = Shear at base of stem = 285.37 kn
M = Moment at Base Slab Level = 996.38 kn-m
MEMBER THICKNESS
M = Design Moment = 996.38 kn-m
R = Resisting Moment Coef. = 1.54E+03 kn/m
b = Unit Width of Member = 1.00 m
dr(Moment) = 804 mm
dr(Shear) = V/(v*b) = 285.37 kn
V = Design Shear = 4.84E+02 kn/m
v = Allowable Shear Stress of Concrete = 590 mm
dr(Moment) > dr(Shear) Use dr = 804 mm
c = Coverage + 1/2 Dia.Reinforcement = 91 mm
tr = dr + c= 804 + 91 = 895 mm
ta = Actual Member Thickness Provided = 1200 mm
ta > tr Design is OK.
HORIZONTAL SHRINKAGE REINFORCEMENT
Ast = Required Area of Steel
= K1 * ta * b OR = K1 * 380 * b
(for ta 380 mm)
Length of Exposed Length of Abutment = 9.20 m
Member Face ta = Actual Thickness of Memb = 1200 mm
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> 9 m 0.0025 0.0020
Ast(Exposed Face) = 0.0025 * 380 * 1000 = 950 mm
Use 16 mm @ 200 mm c/c (Ast = 1005 mm)
Ast(Earth Face) = 0.0020 * 380 * 1000 = 760 mm
Use 16 mm @ 250 mm c/c (Ast = 804 mm)
VERTICAL EXPOSED FACE REINFORCEMENT
Length of Member = Height of Returnwall (H + Ta) = 7.20 m < 9 m
ta = Actual Thickness of Member = 1200 mm > 380 mm
K1 (Exposed Face) = 0.0025
Ast = 0.0025 * 380 * 1000 = 950 mm
Use 16 mm @ 200 mm c/c (Ast = 1005 mm)
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The allowable bond stress is compared to the actual bond stress to determine whether
the design is adequate.
bs(allow) > bs(actual) Design is OK. 12 * Bar Diameter Use dx = = 942 mm 1 m Curtailment should be made.
CHECK SHRINKAGE REINFORCEMENT
Ast(Moment) = 1/2 * Ast(Moment, at Base Slab Level Section)
= 1/2 * 5004 = 2502 mm
Ast(Shrinkage) = 760 mm
Ast(Moment) > Ast(Shrinkage) Use x = 2.37 m
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da > 12 * Bar Diameter Use dx = 658 mm 1 m Curtailment should be made.
CHECK SHRINKAGE REINFORCEMENT
Ast(Moment) = 1/4 * Ast(Moment, at Apron Level Section)
= 1/4 * 5004 = 1251 mm
Ast(Shrinkage) = 760 mm
Ast(Moment) > Ast(Shrinkage) Use x = 3.89 m tr Design is OK.
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HORIZONTAL SHRINKAGE REINFORCEMENT
Ast = Required Area of Steel
= K1 * ta * b OR = K1 * 380 * b
(for ta 380 mm)
Length of Exposed Length of Abutment = 0.00 m
Member Face ta = Actual Thickness of Memb = 500 mm
9 m 0.0025 0.0020
Ast(Exposed Face) = 0.0025 * 380 * 1000 = 950 mm
Use 16 mm @ 200 mm c/c (Ast = 1005 mm)
Ast(Earth Face) = 0.0020 * 380 * 1000 = 760 mm
Use 16 mm @ 250 mm c/c (Ast = 804 mm)
VERTICAL EXPOSED FACE REINFORCEMENT
Length of Member = Height of Returnwall (H + Ta) = 1.68 m < 9 m
ta = Actual Thickness of Member = 500 mm > 380 mmK1 (Exposed Face) = 0.0025
Ast = 0.0025 * 380 * 1000 = 950 mm
Use 16 mm @ 200 mm c/c (Ast = 1005 mm)
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REINFORCEMENTS
Member Bar dia Spacing Ast
moment shrink @ provided
(mm) (mm) (mm) (mm c/c) (mm)
STEM Ver exp face - 950 16 200 1005
Ver earth face 5004 760 28 100 6158
Hor exp face - 950 16 200 1005
Hor earth face - 760 16 250 804
Ver exp face - 950 16 200 1005
Ver earth face 2244 760 25 200 2454
Hor exp face - 950 16 200 1005
Hor earth face - 760 16 250 804
BAR CURTAILMENTS
Curt. ht. Depth of Curt. pt. Ast Ast
Member Curtailment from top sectn.at 12 * above bot momt. shrink
No. h curt.pt. slab, x
(m) da (mm) (mm) (m) (mm) (mm)STEM 1st curtailm 4.57 942 336 2.37 2502 760
2nd curtail 2.77 658 336 3.89 1251 760
MEMBER THICKNESS
Member thickness
Member Moment Shear
dr(mom) dr(shear) tr(req) ta(act)
(kn-m) (kn) (mm) (mm) (mm) (mm)
STEM 996.38 285.37 804 590 895 1200
BACK
WALL
Required Provided
Reinforcement in
Directions and at Top
and Bottom
Ast required