I. BRIDGE GIRDER
:-1 CRANE SPECIFICATIONS :-CAPACITY OF CRANE =
MAIN HOIST = 25.00 Tonnes
AUX. HOIST = 5.00 Tonnes
SPAN OF CRANE (L) = 15.08 Metres
CLASS/DUTY OF CRANE = 2
2 DATA REQUIRED FOR CALCULATIONS
:-VERTICAL IMPACT FACTOR = 1.30 (Table 2 of IS:807)
VERTICAL SEISMIC FACTOR = - gm
FACTOR FOR VERTICAL FORCES CONSIDERED = 1.300
DUTY FACTOR = 0.95 (Table 2 of IS:807)
FACTOR FOR HORIZONTAL FORCES = 0.05 (Table 2 of IS:807) SEISMIC FACTOR FOR HORIZONTAL FORCES = - gm
FACTOR FOR HORIZONTAL FORCES CONSIDERED = 0.050
WEIGHT OF TROLLEY = 6.75 Tonnes
CT LEADING WHEEL LOAD (without Impact) = 8.900 Tonnes CT LEADING WHEEL LOAD (with Impact) = 11.065 Tonnes CT TRAILING WHEEL LOAD (without Impact) = 6.975 Tonnes CT TRAILING WHEEL LOAD (with Impact) = 8.560 Tonnes
CT WHEEL BASE = 2.60 Metres
ALLOWABLE VERTICAL DEFLECTION = 1.676 cms (Clause 7.4.1 of IS:807)
3 SELECTION OF SECTION AS
BELOW:-TOP PLATE :- AREA Ixx Iyy
WIDTH = 430 mm 51.6 6.19 7,950.70 THICKNESS = 12 mm WEB PLATES :-HEIGHT = 1,100 mm 66 66,550.00 1.98 THICKNESS = 6 mm BOTTOM PLATE :-WIDTH = 374 mm 44.88 5.39 5,231.36 THICKNESS = 12 mm
CENTRE to CENTRE of WEB PLATES = 380 mm DISTANCE OF B.PLATE FROM WEB BOTTOM = 10 mm 4 PROPORTIONS OF SECTION
:-SPAN/DEPTH RATIO (Should be < 25) = 13.71 O.K. SPAN/WIDTH RATIO (Should be < 60) = 40.32 O.K. WIDTH/FLANGE THK RATIO (Should be < 60) = 31.17 O.K.
Io(min) = 144.61 cm^4
FLANGE PROPORTIONS :- Io(max) = 142.18 cm^4
CLEAR FL.WIDTH TO FL.THK RATIO = 31.17 Io(act) = - cm^4 NOT REQD
STRUCTURAL CALCULATIONS
for 25/5 Tonne D.G.E.O.T.Crane for
for INDURE Pvt. Ltd., New Delhi.
(If this ratio is >38 then one longitudinal stiffner is to be
provided at the centre of the compression flange) a = 81.00 cm
SIZE OF THE LONGITUDINAL STIFFNER b = 37.40 cm
HEIGHT = - mm As = - cm^2
THICKNESS = - mm St.thk = 1.20 cm
AREA = - cm^2 ht = 12.5 cm
thk = 1.6 cm
WEB PROPORTIONS
:-a) FOR UNSTIFFENED WEBS: THE GREATER OF
d1*ª / 816 = 21.31 mm
d1*ªfy / 1344 = 12.94 mm
d1 / 85 = 12.94 mm
AS PER ISS DISTANCE BETWEEN FULL DEPTH STIFFNERS = 1,620 mm AS PER RAIL DISTANCE BETWEEN FULL DEPTH STIFFNERS = 1,980 mm CONSDERED DISTANCE BETWEEN FULL DEPTH STIFFNERS = c = 1,620 mm
b) FOR VERTICALLY STIFFENED WEBS: THE GREATER OF
h / 180 = 6.11 mm
d2*ªfy / 3200 = 5.44 mm
d2 / 200 = 5.50 mm
c) FOR VERTICALLY & HORIZONTALLY STIFFENED WEBS: THE GREATER OF
h1 / 180 = 1.21 mm
h2 / 180 = 4.87 mm
d2*ªfy / 4000 = 4.35 mm
d2 / 250 = 4.40 mm
d) FOR VERTICALLY & HORIZONTALLY STIFFENED WEBS: THE GREATER OF
h11 / 180 = 1.21 mm
h12 / 180 = 1.79 mm
h2 / 180 = 3.03 mm
d2*ªfy / 6400 = 2.72 mm
d2 / 400 = 2.75 mm
DISTANCE OF 1st CENTRE LINE OF LONG. STIFFNER = 220 mm DISTANCE OF 2nd CENTRE LINE OF LONG. STIFFNER = - mm VERTICAL STIFFNERS
:-MINIMUM REQUIRED THICKNESS OF WEB PLATE = t = 3.03 mm THE MAXIMUM PERMITTED CLEAR DISTANCE BETWEEN VERTICAL
STIFFNERS FOR WEB THICKNESS t = c = 1,620 mm CLEAR DISTANCE BETWEEN HOR. STIFFNER / COMP. FLANGE
AS APPLICABLE & TENSION FLANGE = d = 877 mm MINIMUM I OF THE VERTICAL STIFFNER = 10,760 mm4 SIZE OF THE VERTICAL STIFFNER
HEIGHT = 25.00 mm 4.87 NO 2nd HORIZONTAL STIFFNER REQUIRED 3.03 O.K. 21.31 VERTICAL STIFFNERS ARE TO BE PROVIDED 6.11 1 HORIZONTAL STIFFNER IS TO BE PROVIDED
THICKNESS = 6.00 mm
ACTUAL I = 31,250 mm4
HORIZONTAL STIFFNERS
:-1. 1st HORIZONTAL STIFFNER
MINIMUM I OF THE 1st HORZ. STIFFNER = 180,857 mm4 SIZE OF THE 1st HORZ. STIFFNER
HEIGHT = 50.00 mm
THICKNESS = 6.00 mm
ACTUAL I = 250,000 mm4
2. 2nd HORIZONTAL STIFFNER
MINIMUM I OF THE 2nd HORZ. STIFFNER = NA mm4
SIZE OF THE 2nd HORZ. STIFFNER
HEIGHT = 45.00 mm
THICKNESS = 8.00 mm
ACTUAL I = 243,000 mm4
5 PROPERTIES OF ABOVE SECTION
:-AREA OF SECTION A = 228.48 cm2
DISTANCE EXTREME FIBRE exx = 57.07 cm
MOMENT OF INERTIA Ixx = 425,666.31 cm4
SECTION MODULUS Zxx (t)= 7,459.01 cm
3
SECTION MODULUS Zxx (c)= 7,863.41 cm3
MOMENT OF INERTIA (whole section) Iyy = 60,838.02 cm4 MOMENT OF INERTIA (top flange) Iyy = 30,419.01 cm4 SECTION MODULUS (whole section) Zyy = 2,829.68 cm3 SECTION MODULUS (top flange) Zyy = 1,414.84 cm
3
RADIUS OF GYRATION Ryy = 16.32 cms
CENTRE OF GRAVITY C1 = 54.13 cms
DISTANCE EXTREME FIBRE C2 = 57.07 cms
MEAN COMPRESSION FLANGE THK. = 1.20 cms
DEPTH OF GIRDER = 111.20 cms
UNSTIFFENED DEPTH OF WEB = d = 87.70 cms 6 CHECK FOR SELENDERNESS RATIO
:-SELENDERNESS RATIO (L/Ryy) = 92.41
( As per Clause 7.3.2 of IS:807 L/Ryy <300 )
Hence O.K. 7 CHECK FOR DEFLECTION
VERTICAL DEFLECTION
:-CT LEADING WHEEL LOAD (without Impact) P1 = 8,900 kg CT TRAILING WHEEL LOAD (without Impact) P2 = 6,975 kg
CRANE SPAN l = 1,508 cm RESULTANT DIST. FROM L. WHEEL = 114.24 cm
DIST L.WHEEL FROM CENTRE = 57.12 cm
DIST L.WHEEL FROM END a = 696.88 cm
END REACTIONS, Rb = 8,538.79 kg END REACTIONS, Ra = 7,336.21 kg INTEGERATION CONSTANT C1 = -2,126,544,398.93 CONSTANT u = -1,563.79 CONSTANT v = 12,404,497.64 CONSTANT w = -8,575,323,675.57
DISTANCE OF POINT OF MAX. DEFLECTION = 765.11 cms ACTUAL DEFLECTION AT RATED LOAD = 1.21 cms ( with Trolley at the centre of Span )
ALL. DEFLECTION AT RATED LOAD = 1.68 cms As 1.21 < 1.68 Hence SAFE in Deflection 8 CHECK FOR STRESSES
:-8.1 ALLOWABLE COMPRESSIVE STRESSES IN BENDING :- (for Selected Section) ( As per Clause 6.2.4 of IS:800 )
Y = 310.29 Mpa
X = 317.91 Mpa
K1 (As per Table 6.3 of IS:800) = 1.00
w = 0.50
K2 (As per Table 6.4 of IS:800) =
-ELASTIC CRITICAL STRESS fcb = 335.15 Mpa
( As per Clause 6.2.3 of IS:800 )
T / t = 2.00
d1 / t = 146.17
1344 / ª fy = 85.00
MAXIMUM COMPRESSIVE STRESS = 114.72 Mpa
ALLOWABLE COMPRESSIVE STRESS = 108.98 Mpa
MAXIMUM TENSILE STRESS = 165.00 Mpa
ALLOWABLE TENSILE STRESS = 156.75 Mpa
8.2 VERTICAL STRESSES
:-LEADING WHEEL LOAD (with Impact) = 11,065.00 kg TRAILING WHEEL LOAD (with Impact) = 8,560.00 kg RESULTANT DIST. FROM L. WHEEL = 130.85 cm
DIST L.WHEEL FROM CENTRE = 65.43 cm
DIST L.WHEEL FROM END = 688.57 cm
WEIGHT PER METRE OF SECTION = 200.84 kg/m WEIGHT PER METRE OF CT RAIL = 30.00 kg/m WEIGHT PER METRE OF PLATFORM = 100.00 kg/m
WEIGHT OF EACH LT MACHINERY = 500.00 Kg
DISTANCE LT M/C FROM RAIL CENTRE = 150.00 cms
END REACTIONS, Rb = 13,658.50 kg
MAXIMUM BENDING MOMENT = 7,372,980.50 kg-cm VERTICAL BENDING STRESS (t) = 97.00 Mpa VERTICAL BENDING STRESS (c) = 92.01 Mpa 8.3 HORIZONTAL STRESSES
HORIZONTAL FORCES DUE TO :-a) TROLLEY & LOAD (at each wheel) =
LEADING WHEEL LOAD = 553.25 kg
TRAILING WHEEL LOAD = 428.00 kg
RESULTANT DIST. FROM L. WHEEL = 130.85 cm
DIST L.WHEEL FROM CENTRE = 65.43 cm
DIST L.WHEEL FROM END = 688.57 cm
b) BRIDGE GIRDER = 0.17 kg/cm
WIND LOADS DUE TO
:-a) TROLLEY (at each wheel) = - kg
b) LOAD (at each wheel) = - kg
c) BRIDGE GIRDER = - kg/cm
END REACTIONS, Rb = 657.92 kg
END REACTIONS, Ra = 572.78 kg
MAXIMUM BENDING MOMENT = 355,184.69 kg-cm
HORIZONTAL BENDING STRESS = 12.32 Mpa
8.4 MAXIMUM TOTAL BENDING STRESS = 104.33 Mpa
As 97.00 < 156.75 SAFE in Bend. Stresses in Tension As 104.33 < 108.98 SAFE in Bend. Stresses in Comp. 9 CHECK FOR SHEAR STRESS IN WEB
:-( As per Clause 6.4.2 a) & Table 6.6A of IS:800 )
DEPTH/THICKNESS RATIO = 146.17
DISTANCE BETWEEN STIFFNERS = c = 162.00 cms
RATIO c/d = 1.47
MAXIMUM AVERAGE SHEAR STRESS = 93.00 Mpa (As per Clause 6.4.1 of IS:800)
MAXIMUM SHEAR STRESS (0.45*fy) = 112.50 Mpa
MINIMUM OF THE ABOVE TWO = 93.00 Mpa
ALLOWABLE AVERAGE SHEAR STRESS = 88.35 Mpa
MAXIMUM SHEAR NEAR ENDS = 17,106.28 kg
GIRDER END SECTION AS SHOWNTOP PLATE :-WIDTH = 430 mm THICKNESS = 12 mm BOTTOM PLATE :-WIDTH = 600 mm THICKNESS = 16 mm WEB PLATES :-HEIGHT = 200 mm THICKNESS = 6 mm
PROPERTIES OF ABOVE SECTION
:-AREA OF SECTION A = 171.60 cm^2
MOMENT OF INERTIA Ixx = 16,423.62 cm^4
CENTRE OF GRAVITY C1 = 14.05 cms
DISTANCE EXTREME FIBRE C2 = 8.75 cms
SHEAR STRESS IN WEB UP FROM CENTROID = 59.14 Mpa SHEAR STRESS IN WEB DOWN FROM CENTROID = 64.97 Mpa
MAXIMUM SHEAR STRESS = 64.97 Mpa
As 64.97 < 88.35 Hence SAFE in Shear Stresses 10 CHECK FOR DISTANCE BETWEEN FULL DEPTH STIFFNERS
:-(Please refer Clause 6.7.4.2 of IS:800)
MINIMUM DISTANCE = (0.33*d) = 36.30 cms
MAXIMUM DISTANCE = (1.5*d) = 165.00 cms
DISTANCE CONSIDERED = c = 162.00 cms
As 162.00 ê 165.00
And 162.00 > 36.30 Hence O.K. 11 CHECK FOR MINIMUM THICKNESS OF VERTICAL STIFFNER PLATES
:-ALL STIFFNERS SH:-ALL BEAR AGAINST TOP PLATE AND SH:-ALL BE WELDED TO THE WEB PLATES. ITS THICKNESS SHALL BE SUFFICIENT TO RESIST THE TROLLEY WHEEL LOAD IN BEARING ON THE ASSUMP-TION THAT THE WHEEL LOAD IS DISTRIBUTED OVER A DISTANCE EQUAL TO THE WIDTH OF THE RAIL BASE PLUS TWICE THE DISTANCE FROM THE RAIL BASE TO THE TOP OF STIFFNER PLATE.
( As per Clause 6.3 of IS:800 )
PERMISSIBLE BEARING STRESS = (0.75*fy) = 187.50 Mpa
ALLOWABLE BEARING STRESS = 178.13 Mpa
TROLLEY WHEEL LOAD (without Impact) = 8.90 Tonnes WIDTH OF THE RAIL BASE + TWICE THE
DISTANCE FROM TOP OF STIFFNER = 13.35 cms MINIMUM STIFFNER PLATE THICKNESS = 3.67 mm STIFFNER PLATE THICKNESS SELECTED = 5.00 mm
As 5.00 > 3.67 Hence O.K. & SAFE 13 CHECK FOR MINIMUM DISTANCE BETWEEN STIFFNERS
:-TROLLEY WHEEL LOAD (without Impact) = 8.90 Tonnes SECTION MODULOUS OF CT RAIL = 116.00 cm^3 MINIMUM DISTANCE BETWEEN ADJECENT
STIFFNERS (LONG OR SHORT) = 989.91 mm
CONSIDERED MINIMUM DISTANCE = 810.00 mm
As 810.00 < 989.91 Hence O.K. & SAFE
II. END CARRIAGES
:-1 END CARRIAGE SPECIFICATIONS
END CARRIAGE WHEEL BASE = 4.80 Metres
L.T. WHEEL BASE = 4.80 Metres
2 DATA REQUIRED FOR CALCULATIONS :-(When Trolley is at one End)
LIVE LOAD (without Impact) = 14.82 Tonnes
LIVE LOAD (with Impact) = 18.32 Tonnes
DEAD LOAD = 2.99 Tonnes
ALLOWABLE VERTICAL DEFLECTION = 0.53 cms 3 SELECTION OF SECTION AS
BELOWTOP & BOTTOM PLATE
:-WIDTH = 228 mm
THICKNESS = 8 mm
WEB PLATES
:-HEIGHT = 520 mm
THICKNESS = 8 mm
CENTRE to CENTRE of WEB PLATES = 220 mm
4 PROPORTIONS OF SECTION
:-SPAN/DEPTH RATIO (Should be < 25) = 9.23 O.K. SPAN/WIDTH RATIO (Should be < 60) = 22.64 O.K. WIDTH/FLANGE THK RATIO (Should be < 60) = 26.50 O.K. 5 PROPERTIES OF ABOVE SECTION
:-AREA OF SECTION A = 119.68 cm^2
MOMENT OF INERTIA Ixx = 44,174.78 cm^4
SECTION MODULUS Zxx = 1,648.31 cm^3
MOMENT OF INERTIA (whole section) Iyy = 11,651.95 cm^4 MOMENT OF INERTIA (top flange) Iyy = 5,825.98 cm^4
SECTION MODULUS Zyy = 1022.10 cm^3
RADIUS OF GYRATION Ryy = 9.87 cms
CENTRE OF GRAVITY C1 = 26.80 cms
DISTANCE EXTREME FIBRE C2 = 26.8 cms
MEAN COMPRESSION FLANGE THK. = 0.80 cms
DEPTH OF GIRDER = 53.60 cms
AREA OF WEB (Near End) = 26.88 cm^2
6 CHECK FOR SELENDERNESS RATIO
:-SELENDERNESS RATIO (L/Ryy) = 48.65
( As per Clause 7.3.2 of IS:807 L/Ryy <300 )
Hence O.K. 7 CHECK FOR DEFLECTION
:-ACTUAL DEFLECTION AT RATED LOAD = 0.3681322 cms
( with Trolley at the end of Span )
ALL. DEFLECTION AT RATED LOAD = 0.53 cms
As 0.37 < 0.53 Hence SAFE in Deflection 8 CHECK FOR STRESSES
:-8.1 ALLOWABLE COMPRESSIVE STRESSES IN BENDING :- (for Selected Section) ( As per Clause 6.2.4 of IS:800 )
Y = 1,119.80 Mpa
X = 1,134.46 Mpa
K1 (As per Table 6.3 of IS:800) = 1.00
w = 0.50
K2 (As per Table 6.4 of IS:800) = 0.00
ELASTIC CRITICAL STRESS fcb = 1,134.46 Mpa
( As per Clause 6.2.3 of IS:800 )
MAXIMUM COMPRESSIVE STRESS = 152.14 Mpa
ALLOWABLE COMPRESSIVE STRESS = 144.53Mpa
8.2 VERTICAL STRESSES
:-WEIGHT PER METRE OF SECTION = 107.79 kg/m
END REACTIONS, Ra = Rb = 21,576.86 kg
MAXIMUM BENDING MOMENT = 2,215,623.26 kg-cm
VERTICAL BENDING STRESS = 131.91 Mpa
8.3 HORIZONTAL STRESSES
HORIZONTAL FORCES DUE TO
:-a) TROLLEY & LOAD = 1587.50 kg
END REACTIONS, Ra = Rb = 396.88 kg
MAXIMUM BENDING MOMENT = 31,750.00 kg-cm
HORIZONTAL BENDING STRESS = 3.05 Mpa
8.4 MAXIMUM TOTAL BENDING STRESS = 134.96 Mpa
As 134.96 < 144.53 Hence SAFE in Bending Stresses 9 CHECK FOR SHEAR STRESS IN WEB
:-( As per Clause 6.4.2 a) & Table 6.6A of IS:800 )
DEPTH/THICKNESS RATIO = 65.00
DISTANCE BETWEEN STIFFNERS (1.0*d) = 52.00 cms MAXIMUM AVERAGE SHEAR STRESS = 100.00 Mpa (As per Clause 6.4.1 of IS:800)
MAXIMUM SHEAR STRESS (0.45*fy) = 112.50 Mpa
MINIMUM OF THE ABOVE TWO = 100.00 Mpa
ALLOWABLE AVERAGE SHEAR STRESS = 95.00
MAXIMUM SHEAR NEAR ENDS = 21,576.86 kg
END CARRIAGE END SECTION AS SHOWNTOP PLATE :-WIDTH = 228 mm THICKNESS = 8 mm BOTTOM FLATS :-WIDTH = 80 mm THICKNESS = 20 mm WEB PLATES
:-HEIGHT = 153 mm
THICKNESS = 8 mm
CENTRE to CENTRE of WEB PLATES = 220 mm PROPERTIES OF ABOVE SECTION
:-AREA OF SECTION A = 74.72 cm2
MOMENT OF INERTIA Ixx = 3,839.43 cm4
CENTRE OF GRAVITY C1 = 10.19 cm
DISTANCE EXTREME FIBRE C2 = 7.91 cm
SHEAR STRESS IN WEB UP FROM CENTROID = 61.55 Mpa SHEAR STRESS IN WEB DOWN FROM CENTROID = 76.22 Mpa
MAXIMUM SHEAR STRESS = 76.22 Mpa
As 76.22 < 95.00 Hence SAFE in Shear Stresses 10 CHECK FOR DISTANCE BETWEEN FULL DEPTH STIFFNERS
:-(Please refer Clause 6.7.4.2 of IS:800)
MINIMUM DISTANCE = (0.33*d) = 17.16 cms
MAXIMUM DISTANCE = (1.5*d) = 78.00 cms
DISTANCE CONSIDERED = (1.0*d) = 52.00 cms As 52.00 < 78.00
And 52.00 > 17.16 Hence O.K. 11 CHECK FOR MINIMUM THICKNESS OF WEB PLATES
:-( As per Clause 6.7.3.1 b) & Table 6.7 of IS:800 )
I) 1/180 OF SMALLEST CLEAR PANEL = 2.89 mm II) MAXIMUM OF
:-d2*(fy)^.5/3200 = 0.19 mm
d2/200 = 2.60 mm
GREATER OF I) & II) = 2.89 mm
CONSIDERED THICKNESS OF WEB PLATE = 8.00 mm As 8.00 > 2.89 Hence O.K.
