Project 2

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	200 kN/m2
Roof slope	1 in 12

Assume suitable sections for structural elements. Follow IS800:2007, IS1893 and IS 875

1. Prepare a Design Basis Report for the project
2. Create structural model using STAAD Pro Connect Edition
3. Prepare DL, LL, WL and EQL load calculations as per IS 875 standards
4. Design using MS – Excel
   1. Steel column
   2. Rafter
   3. Base plate
   4. Pedestal
   5. Z- purlin

1. Design Foundations using STAAD Foundation.
2. Attach necessary sketches and drawings wherever required.
3. All stipulations, assumptions and design parameter must adhere to Indian Standards.

Solution

slope calculation

slope = 1 in 20

width = 30m

Half width = 15m

X/15 = 1/12

X = 1.25m

Total height = eave height + X = 9 + 1.25 = 10.25m

Geometry :

Specifications

Supports

Pinned supports are added to the whole structure

Load definations

Seismic load defination for given conditions

Seismic load assignments

Dead loads

Live loads

Wind loads

Design parameters

Design commands

after analysing the structure

Foundation design

Design basis report is attached as a pdf file below in the file section

Design of steel column :

Flangr thickness = T = 12.7mm

Overall height of column ISMB400 = h = 400mm

Clear depth between flanges = d = 400-(12.7x2) = 374.6mm

thickness of web = t = 10.6mm

flange width = 2b = bf = 250mm

hence, 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

Type of section:

b.T =125/12.7 = 9.8 < 10.5

dt = 374.6/10.6 = 35.3 < 42 (Table 3.1 of IS800)

Hence, cross section can be classified as compact

Effective sectional area :

Ae = 10,466mm2 (Cl 7.3.2 of IS800)

Effective length :

Both are pinned joint, 3m

slenderness ratio:

KLx/rx = 9000/166.1 = 54.1

KLy/ry = 9000/51.6 = 174.41

Non dimensional effective slenderness ratio

= 3.83

= 0.791

Calculation of X:

= 0.809

Calculation of Fcd:

= 183.86 N/mm2

Factored axial load = AgFcd

= 1924.28kN

Design of rafter :

Span of rafter = 6m

Dead load = 18kN/m

Imposed load = 40kN/m

supporting bearing = 100mm

Yield strength = 250N/mm2

Design load calculation :

Factored load 1.5(DL+LL) = 87kN/m

Section modulus required = Zreq = 65.25X1.1/250 = 287100mm3 = 287.1cm3

Section classification :

ISMB200

Moment of reistance of cross section

= 85.306 (>65.25)

Design of base plate :

Strength of concrete = Fcu = 40N/mm2

yield strength of steel = fy = 250N/mm2

material factor = 1.1kN

Load = 1500kN

steel column section:

Thickness of flange = T = 12.7mm

Area required :

Bearing strength of concrete = 0.4fcu = 16N/mm2

= (1500X1000)/16 = 93750mm2

Let size of plate = Bplate = 450mm

D plate = 300mm

Area of plate = 135000mm2

projection on each side = a=b= 25mm

W = (1500X1000)/(450X300) = 11.11Nmm2

Thickness of base plate (Cl7.4.3.1)

ts = 7.3mm < 12.7mm

hence, size of base plate = 450X350X16mm

Design of pedestal :

Grade of concrete = 40N/mm2

Load = 200kN

Moment = 120kNm

Horizontal shear = 20KN

yield strength = 250N/mm2

Length of base plate = 450mm

Width of base plate = 350mm

C/C distance of bolt in group - Z = 300mm

C/C distance of bolt in group - X = 180mm

Bearing strength of concrete Fc= 16N/mm2

Depth of column = 30mm

Width of column = 250mm

Anchor bolt details:

Dia of anchor bolt = 24mm

No. of anchor bolts in each side = 4

total no. of anchor bolts = n = 8

Gross area of bolt Asb = 452.16mm2

Net area of bolt Anb = 352mm2

Ultimate tensile strength of bolt fub = 400Nmm2

base plate details:

Ultimate tensile strength of plate fu = 490N/mm2

Thickness of plate = 16mm

Yield stress of plate = 330N/mm2

Anchor bolt design:

Area of the plate = 157500mm2

Maximum pressure = (F/A)+(6Mz/BL2) =10.6Nmm2 <16

Minimum pressure = -9.04N/mm2 < 16

Centroid = 242.89mm

a=L/2-C/3 = 144.01mm

e = (L-Ld)/2 = 75mm

Y = (L-C/3-e) =294.04mm

Tension in anchor bolt along the length of plate , FT = (MZ-Fa)Y = 364.38

tension per bolt = 91KN

shear per bolt = 1.63kN

Shear check :

factored shear force =

Vsb = 1.63kN

Vdsb = 81290.9N

Factored = 65.03KN

tensile check :

Factored tensile force in bolt, Tb = 91.1KN

tensile strength of bolt Td,b = 98.65KN

Combined unity check:

Vsb/Vdb =0.025

Tb/Tdb = 0.92

unity check = 0.85<1

Anchor bolt length :

Bond strength in tension = 1.4N/mm2

Anchor length required = 863.44mm

Let, the anchor bolt length be 900mm

Design of Z-purlin :

span of purlin = 5m

spacing of purlin = 1.5m

No.of sag rods = 1

Slope of roof = 4.76 = 5 degree

Dead load

weight of sheeting = 6Kg/m2

self weight of purlin = 4.22Kg/m2

Additional load = 10% = 0.42Kg/m2

Total dead load = 0.106Kg/m2

Live load

Live load on roof = 75Kg/m2

Wind load

Basic wind speed = 50m/s

Terrain category = 2

Building class = B

K1=1

K2=1

K3=1

Design wind speed =Vz = 57m/s

Design wind pressure = Pz = 1949.9m/s

Length of building, L =50m

Width of building = W = 30m

Height of building, H= 10.25m

Height of eves = 9m

h/w = 0.34

L/w = 1.667

External pressure coefficient

Maximum downward=Cpe=-0.4

Maximum upward=Cpe=-0.7

Internal pressure coefficient

Maximum positive=Cpi=0.5

Maximum negative=Cpi=-0.5

for maximum upward wind force

Max uoward Cpe =-0.7

cpi=-0.5

Cpe+Cpi=-1.2

Pz = 1.95

Wind pressure for purlin design = -2.339KNmm2

For maximum upward wind force

Max upward Cpe=-0.4

Cpi=-0.5

Cpe=Cpi=-0.1

Pz=1.65

Wind pressure for purlin design = 0.195kN/m2

design load calculation:

Spacing of purlin = 1.5m

Slope of roof = 5degree

Total dead load = 0.096

DL normal component = 0.144KN/m

DL tangential component = 0.013KN/m

Total live load = 0.75

Ll normal component = 1.121kN/m

LL tangential component = 0.068KN/m

Total wind load = -2.339

WL normal component =-3.496KN/m

WL normal component = 0.291KN/m

Maximum normal component = DL+LL=1.265KN/m

Purlin section:

selected section Z200X6X2.3

area=8.07cm2

Weeight of purlin = 6.335Kg/m.

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

Maximum moment due to vertical load = weight of trolley+Crane capacity = 40+250 =290KN

Self-weight of crane girder excluding trolley = 100KN

For maximum reaction on gantry girder, the moving load should be as close the gantry girder as possible

Ra = 9290X8/9) + (100/2)

= 307.77KN

This load is transferred to gantry girder, through two wheel, the wheel base being 3m.

So load on gantry girder from each wheel = 307.77/2 = 158.88KN

Maximum moments due to moving loads occur under a wheel when the c.g of wheel loadand the wheel are eqidistant from the centre of girder

Rd =(230.83X(3-1.5-0.75)+(230.83 X (3+0.75)))/7 =148.4KN

Max moment, Me =148.4X2.25 = 333.90KN-m

Moment due to impact = 0.25X333.9= 83.47KN-m

Assume self weight of girder = 2KN-m

Dead load due to self weight + rails = 2+0.2=2.2KN-m

Factored DL = 2.2X1.5 = 3.3KN-m

Moment due to DL = 20.21KN-m

factored moment due to all vertical loads, Mz = 333.9 + 83.47 + 20.21 = 437.58KN-m

Maximum moment due to lateral force:

Horizontal force transferred to rails = 10% of weight of trolley plus load lifted =(10/100)X(250+40) = 29KN

This is distributed to 4 wheels

so, horizontal force on each wheel = 29/4 =7.25KN

Factored horizontal force on each wheel = 1.5X7.25 = 10.875KN

For maximum moment in gantry girder the position of loads is same earlier except that is horizontal, hence by proportioning we get,

My =(10.875/230.83)X333.90 = 15.73KNm

Shear force:

for maximum shear force on the girder, the trailing wheel should just be on girder.

Vertical shear due to wheel loads = 230.83+(230.86X3)/7 = 329.75KN

Priliminary section :

maximum economic depth, L/12 = 7000/12 = 583.33mm

width of compression flange may be taken as 1/40 or 1/30 of span

so, flange width can be taken, L/40 = 7000/40 = 175mm to L/30 =7000/30 = 233.33mm

Required Zp = 1.4X(M/fy) = 2450X10^3mm^3

Let us try a ISMB 550 with ISMC 250 0n compression flange