Project 2
ANS:1
Design a Warehouse Building located in Chennai using STAAD Pro Connect Edition. The specification must be as follows:
WIDTH=30m
LENGTH=50m
EAVE HEIGHT=9m
BAY SPACING=6m
SOIL TYPE=MEDIUM
SAFE BEARING CAPACITY=200KN/m^2
ROOF SLOPE=1 IN 12
Assume suitable sections for structural elements. Follow IS800:2007, IS1893 and IS 875
DESIGN OF STEEL COLUMN:
FLANGE THICKNESS=T=12.7MM
HEIGHT OF COLUMN ISMB400=h=400MM
CLEAR DEPTH BETWEEN FLANGE=d=400-(12.7*2)
=374.5MM
THICKNESS OF WEB t=10.6mm
FLANGE WIDTH=2b=bf=250mm
HALF FLANGE WIDTH=b=125mm
SELF WEIGHT=W=0.822KN/m
AREA OF CROSS SECTION=A=10466mm2
RADIUS OF GYRATION ABOUT X=rx=166.1mm
RADIUS OF GYRATION ABOUT Y=ry=51.6mm
FLANGE CRITERION b/T=9.84
WEB CRITERION d/t=35.34
e=1
b/T<10.5
d/t<42
THE SECTION IS CLASSIFIED AS COMPACT
STEP:2
EFFECTIVE LENGTH
AS BOTH ENDS PIN JOINTED
KLx=9m
KLy=9m
KLz=9m
SLENDERNESS RATIO:
KLx/rx=9/166.1
=54.18
KLy/ry=9/51.6
=174.42
NON DIMENSIONAL EFFECTIVE SLENDERNESS RATIO
STEP:3
TO CALCULATE
h/bf=1.60>1.2
t=12.7mm
SO BUCKLING CLASS=b
a=0.34
=0.5(1+a(y-02)+y^2)
=2.73
STEP 4:
CALCULATION OF x
x=0.216N/mm^2
STEP:5
CALCULATION OF fcd=xfy/ym
=49.17
STEP:6
FACTORED AXIAL LOAD Pd=Afcd
=514.614kN
DESIGN FOR RAFTER
STEP:1
DESIGN LOAD CALCULATION:
FACTOR LOAD=18*1.5+40*1.5
=87KN/M
FACTOR BENDING MOMENT=(87*6*6)/(8)
=391.5KNM
STEP 2
SECTION MODULUS REQUIRED
PROPERTIES OF SELECTED SECTION
ISMB 250
A=475.5MM^2
D=250MM
B=125MM
t=6.9
T=12.5MM
Izz=5131.6CM^4
Iyy=344.5CM^4
Zp=459.76CM^3
FLANGE CRITERIA =B/2T
=125/(2*12.5)
=5
WEB CRITERIAN=(D-2T)t
=(250-(2*12.5))*6.9
=32.61
e=1
B/2T<9.4
(D-2T)t<83.9
HENCE THE SECTION IS PLASTIC
STEP:3
MOMENT OF RESISTANCE OF THE CROSS SECTION
MOMENT Md=(Zp*Fy)/ym
=((459.76*1000*250)/1.1))/10^6
=104.49KNM< 391.50KNM
STEP:4
SHEAR RESISTANCE OF THE CROSS SECTION
SHEAR CAPACITY Vc=0.6fyAv/ym
Av=250*6.9
=1725MM^2
Vc=(0.6*250*1725)/1.1
=235.22KN
FACTOR SHEAR V=(87*6)/(2)
=261 KN
V/Vc=1.11>0.6
STEP:5
CHECK FOR WEB BUCKLING
SLENDERNESS RATIO OF WEB=2.5d/t
d=250-12.5-12.5
=225
=(2.5*225)/6.9
=81.52MM
DESIGN COMPRESSIVE STRESS fc=203 N/MM^2
Pw=315.16>261
HENCE WEB IS SAFE AGAINST SHEAR BUCKLING
STEP:6
CHECK FOR WEB CRIPPLING AT SUPPORT
ROOT RADIUS OF ISMB 250 R=13MM
THICKNESS OF FLANGE tf=12.5
=tf+R
=12.5+13
=25.5MM
DISPERSION LENGTH =2.5*25.5
=63.75MM
PCRIP=245.63KN>126
HENCE SECTION ADEQUATE FOE WEB CRIPLING
STEP:7
CHECK FOR SERVICEABILITY DEFLECTION
DESIGN LOAD=58kN/M
DEFLECTION=(5*58*(6*1000)^4)/(384*2*10^5*5131.6*10^4)
=95.36MM
ALLOWABLE DEFLECTION =30MM
HENCE SERVICEABILITY IS SATISFIED.
B)
DESIGN FOR BASE PLATE
STEP:1
STRENGTH OF CONCRETE fcu=40N/MM^2
YIELD STRENGTH OF STEEL fy=250
MATERIAL FACTOR ym=1.1KN
FACTOR LOAD =1500KN
STEP:2
STEEL COLUMN SECTION
THICKNESS OF FLANGE=12.7MM
STEP:3
AREA REQUIRED
BEARING STRENGTH OF CONCRETE=0.4fcu
=0.4*40
=16 N/MM^2
AREA REQUIRED=(1500*10^3)/16
=93750MM^2
LET SIZE OF PLATE BPLATE=350MM
DPLATE=300MM
=105000MM^2
LET PROJECTION FOR EACH SIDE:a=b =25MM
W=(1500*1000(/(105000)
=14.28N/MM^2
THICKNESS OF SLAB BASE=SQRT((2.5*14.28(25^2-(0.3*25^2))*1.1)/250)
=8.28MM<12.70
SO USE THE BASE PLATE OF SIZE 350MM*300MM*16MM
DESIGN OF PEDESTAL:
GRADE OF CONCRETE=40N/mm^2
LOAD=123kN
MOMENT=116KNm
HORIZONTAL SHEAR=13kN
YIELD STRENGTH=250N/mm^2
LENGTH OF BASE PLATE L=450MM
WIDTH OF BASE PLATE B=350MM
C/CDISTANCE OF BOLT GROUP IN Z=300mm
C/C DISTANCE OF BOLT GROUP IN X=180mm
BEARING STRENGTH OF CONCRETE fc=16N/mm^2
DEPTH OF COLUMN D=300MM
WIDTH OF COLUMN W=250MM
STEP:1
ANCHOR BOLT DETAILS
DIA OF ANCHOR BOLT=24mm
NO OF ANCHOR BOLT ON EACH SIDE=4
TOTAL NUMBER OF ANCHOR BOLT n=8
GROSS AREA OF THE BOLT Asb=452.16mm^2
NET AREA OF BOLT Anb=352mm^2
ULTIMATE TENSILE STRENGTH OF THE BOLT fub=400N/mm^2
Fyb=240N/mm^2
STEP:2
BASE PLATE DETAILS
ULTIMATE TENSILE STRENGTH OF A PLATE fu=490N/mm^2
THICKNESS OF PLATE=16mm
YIELD STRESS OF PLATE=330N/mm^2
STEP:3
ANCHOR BOLT DESIGN
AREA OF THE PLATE=157500mm^2
STRESS AX PRESSURE SIGMA 1=F/A+6*Mz/BL^2
=10.60N/mm^2<16
MIN PRESSURE SIGMA 2=F/A-6*Mz/BL^2
=-9.04N/mm^2<16
C=L*SIGMA 1/(SIGMA 1+SIGMA 2)
=242.89mm
a=L/2-C/3
=144.04mm
e=(L-Ld)/2
=75mm
Y=(L-C/3-e)
=294.04mm
TENSION PER BOLT=91.10KN
SHEAR PER BOLT V=1.63KN
STEP:4
SHEAR CHECK
FACTORED SHEAR FORCE Vsb=1.63KN
Vd,Sd=81290.9N
FACTOR Vd,Sb=65.03KN
STEP:5
TENSILE CHECK
FACTORED TENSILE FORCE IN BOLT Tb=91.10KN
TENSILE STRENGTH OF BOLT Td,b=Tnb/ymb
Tn,b=0.9*fubAn
=126.72KN
Tn,b=fybAsb(ymb/ym0)
=123.316
LESSER OF TWO VALUE
123.316KN
SO Td,b=98.65kN
STEP 6
COMBINED UNITY CHECK
(Vsb/Vdb)^2+(Tb/Tdb)^2
Vsb/Vdb=0.025
Tb/Tdb=0.92
UNITY CHECK=0.85<1
HENCE OK
STEP:7
ANCHOR BOLT DESIGN
BOND STRENGTH IN TENSION=1.4N/mm^2
ANCHOR LENGTH REQUIRED=Tb/(3.14*d*bd)
=863.44mm
LET ANCHOR BOLT LENGTH=900MM
DESIGN FOR Z-PURLIN:
STEP:1
SPAN OF THE PURLIN=7m
SPACING OF THE PURLINE=1.5m
NUMBER OF SAG RODS:1
SLOP OF THE ROOF=5DEG
STEP:2
DEAD LOAD
WEIGHT OF SHEETING=5KG/m^2
SELF WEIGHT OF PURLIN=4.22Kg/m^2
ADDITIONAL LOAD=10%=0.42Kg/m^2
TOTAL DEAD LOAD=0.096KN/m^2
LIVE LOAD
LIVE LOAD ON ROOF=75Kg/m^2=0.75KN/m^2
WIND LOAD
BASIC WIND SPEED =50m/S
TERRAIN CATEGORY=2
K1=1
K2=1
K3=1
DESIGN WIND SPEED Vz=57m/s
DESIGN WIND PRESSURE Pz=1949.40N/m^2
=1.95KN/m^2
LENGTH OF BUILDING L=50m
WIDTH OF THE BUILDING W=30m
HEIGHT OF THE BUILDING h=10.5m
HEIGHT OF THE BUILDINNG AT EAVES=9m
EXTERNAL PRESSURE COEFFICIENT
Cpe=-0.4
Cpe=-0.7
INTERNAL PRESSURE COEFFICIENT
Cpi=0.5
Cpi=-0.5
FOR MAXIMUM UPWARD WIND FORCE
MAXIMUM UPWARD Cpe=-0.7
Cpi=-0.5
Cpe+Cpi=-1.2
Pz=1.95
WIND PRESSURE FOR PURLIN DESIGN=-2.339kN/m^2
FOR MAXIMUM UPWARD WIND FORCE
MAXIMUM UPWARD Cpe=-0.4
Cpi=0.5
Cpe+Cpi=0.1
Pz=1.95
WIND PRESSURE FOR PURLIN DESIGN=0.195kN/m^2
STEP:3
DESIGN LOAD CALCULATION
SPACING OF PURLIN=1.5m
SLOP OF ROOF=5DEG
TOTAL DEAD LOAD=0.096KN/m
DL NORMAL COMPONENT=0.144KN/m
DL TANGENTIAL COMPONENT=0.013KN/m
TOTAL LIVE LOAD=0.75KN/m^2
LL NORMAL COMPONENT=1.121KN/m
LL TANGENTIAL COMPONENT=0.098KN/m
WL1 WIND LOAD=-2.339KN/m
WL NORMAL COMPONENT=-3.496KN/m
WL2 WIND LOAD=0.195KN/m
WL NORMAL COMPONENT=0.291KN/m
SUMMARY OF LOADS
DL+LL DL+WL1 DL+LL+WL2
NORMAL LOAD 1.265 -3.351 1.556
TANGENTIAL LOAD 0.111 0.013 0.111
DL+LL 0.75(DL+WL1) 0.75(DL+LL+WL2)
NORMAL LOAD 1.265 -2.514 1.167
TANGENTIAL LOAD 0.111 0.009 0.083
MAXIMUM NORMAL COMPONENT=1.265KN/m
STEP:4
PURLIN SECTION
SECTION SELECTED=Z*200*6*2.3
YIELD STRESS OF MATERIAL=2400Kg/cm^2
FLANGE WIDTH=60mm
DEPTH OF SECTION=200mm
THICKNESS t=2.30mm
LENGTH OF LIP LIP I=20mm
INTERNAL BENDING RADIUS=3mm
AREA=8.07cm^2
Zxx=47.72cm^3
Zyy=10.22cm^3
Ixx=477.18cm^4
Iyy=61.34cm^44
WEIGHT OF PURLIN=6.335kg/m^2
CHECK FOR BASIC PROPERTIES
t=2.30MM
W=49.40MM
Fy=2400Kg/cm^2
w/t=21.48<60
OK
CHECK FOR STRESS
SPAN MAJOR AXIS=7m
SPAN MINOR AXIS=2m
BM COEFFICIENT FOR Mxx=10
BM COEFFICIENT FOR Myy=10
DL+LL DL+WL1 DL+LL+WL2
NORMAL LOAD 6.198 16.422 7.625
TANGENTIAL LOAD 0.060 0.007 0.060
Mxx/Zxx 129.878 344.133 159.789
Myy/Zyy 5.895 0.672 5.895
(Mxx/Zyy)+(Myy/Zyy) 135.773 344.805 165.684
MAXIMUM COMPRESSIVE STREE=344.80N/mm^2
STEP:5
COMBINE BENDING AND SHEAR STRESS IN WEB
h/t==84.96
DL+LL DL+WL1 DL+LL+WL Fbw 506.539 673.697 637.697
Fv 735.223 977.847 977.847
ACTUAL STRESS
fbw 129.878 344.133 159.789
fv 5.895 0.672 5.895
fbw/FbW 0.256 0.511 0.237
fv/Fv 0.008 0.001 0.006
SQRT OF SUM OF SQUARES 0.257 0.511 0.237
MAXIMUM COMBIND STRESSES =0.511<1
HENCE OK
STEP:6
CHECK FOR DEFLECTION
NUMBER OF SPANS=3
DEFLECTION=(3/384)*(Wl^4/EI)
w=3.351KN/m
SPAN=6m
E=207400N/mm^2
lxx=477.18cm^4
ALLOWABLE DEFLECTION=34.29
ALLOWABLE DEFLECTION=SPAN/180
=33.33mm>34.29
HENCE NOT OK
ANS:2
Design a simply supported gantry girder to carry electric overhead travelling crane
Given:
Span of gantry girder = 7 m
Span of crane girder = 9 m
Crane capacity = 250 kN
Self-weight of trolley, hook, electric motor etc. = 40 kN
Self-weight of crane girder excluding trolley = 100 kN
Minimum hook approach = 1.0 m
Distance between wheels = 3 m
Self-weight of rails = 0.2 kN/m
