There are more steps you have to following to do design for any building. Up to have we finished eight steps to design structure of building:

1. Select a plan of building 2. Draw the plan of a building in AUTOCAD program and

show columns position. 3. Calculate the slab load, wall load, beam self weight and

total load for each beam in the building.4. Make a staad model.5. Do the columns and beam size and enter it in staad

program.6. Enter the total loads in staad program.7. By using staad program select the grade of concrete and

steel for the full structure of building.8. Do design of columns, beams and slabs of building.

PLAN OF COLLEGE BUILDING

ELEVATION OF COLLEGE BUILDING

Columns position

Assume the load of slab •Overall of slab=?? Lx/d=32 7500/32=dD=234.375mm h= Ø/2+c+d=12/2+20+234.375

=260.375mm*Loading on 1m of slabDl of concrete = vol x uw

=1 x 1 x 0.260 x 24=6.24kn/m2

Dl finishing=1KN/m2

Imposed load live(Qk)=2.5kn/m2

Ultimate load=1.4 x 7.24 x 1.6 x 2.5Wu=14.136kn/m2

LX = 7.5m

LY = 10

.6m

Distribution of slabS1

Ly/lx = 10604.5/7500=1.4 1.4 < 2 two way slab

Long beam =((Wu x lx)/6) x (3-(Lx/Ly)2)= ((14.136 x 7.5)/6) x {3-(7.5/10.6)2} = 44.15kN/m2

Short beam =(Wu x lx)/3= (14.136 x 7.5)/3 = 35.34 KN/m2

S2Ly/lx = 7500/7203=1.4 1.4 < 2 two way slabLong beam =((Wu x lx)/6) x (3-(Lx/Ly)2)= ((14.136 x 7.203)/6) x (3-(7.203/10.6)2) = 43 KN/m2

Short beam =(Wu x lx)/3= (14.136 x 7.203)/3= 34kn/m2

S3Ly/lx = 7500/5353=1.4 1.4 < 2 two way slabLong beam =((Wu x lx)/6) x {3-(Lx/Ly)2) = ((14.136 x 5.353)/6) x (3-(5.353/7.5)2) = 31.4 kn/m2

Short beam =(Wu x lx)/3 = (14.136 x 5.353)/3 = 25.22kn/m2

S4Ly/lx = 8804.5/7500=1.4 1.1< 2 two way slabLong beam=((Wu x lx)/6) x (3-(Lx/Ly)2) = ((14.136 x 7.5)/6) x (3-(7.5/8.8)2) = 40.17 kn/m2

Short beam=(Wu x lx)/3 = (14.136 x 7.5)/3 = 35.34 kn/m2

S5Ly/lx = 45771/3251=14 14> 2 one way slab(Wu x lx)/2 = (14.136 x 3)/2 =21.204kn/m2

Slab load for staircase

Dl of waist slab 1m2

=1.16 x 0.260 x 24 = 6.2 kn/m2

Dl of steps = 4 (0.5 x .25 x .15) x 24=108 kn/m2

Floor finish = 1kn/m2

Total DI load = 10 x 1.4 = 14 kn/m2

Live load = 3 kn/m2

= 3 x 1.6 =4.8 kn/m2

Wu = 14+ 4.8 = 18.8 kn/m2

For staircase design one way slab(Wu x lx)/2 = (18.8 x 5.25)/2 = 49.35 kn/m2

1m

250mm 15

0m

m

Tan Ø=150/250Ø =30.9°

Cos 30.9° =1/xX= 1.16m

Ø

Dl of filling material = 1 x 1 x .3 x 12=3.6 x 1.4 = 5 KN/m2

Wu = 14.13 + 5 = 19.136 KN/m2

Ly/lx = 525/325=1.6 1.6< 2 two way slabshort beam=(Wu x lx)/3 = (19.136 x 3.251)/3= 20.7 KN/m2

Long beam=((Wu x lx)/6) x (3-(lx/ly)2)= ((19.136 x 3.251)/6) x (3-(3.251/5.35)2) = 27.129 KN/m2

Sunken slab load

Filling material

SLAB

Self weight of beam = 1 x 0.25 x 0.6 x 24= 3.6 x 1.4= 5.04 kn/m2

250mm6

00

mm

Load of wall = 1x 0.200 x 3 x 15= 9 x 1.4=12.6 kn/m2

0.2m

3m

34

34

43

43

43

43

43 43 43

34

34

34

34

35.34 35.34 35.34 35.34

35.3435.3435.3435.3435.3435.3435.3435.34

43

44.15

44.15

44.1544.15

25.22

25.22

40.17

40.17

44.15 44.15 44.15 44.15

44.1544.15

31.4 31.4

20.7

20.7

27

.13

27

.13

49.35

49.35

21.2

21.2

Beam

designation

Slap load Wall loadKN/M2

Beam self

weightKN/M2

Total loadKN/M2LHS

KN/M2

RHSKN/M2

AB 0 34 12.6 5.04 51.64

BC 0 34 12.6 5.04 51.64

CD 0 34 12.6 5.04 51.64

DE 0 44.15 12.6 5.04 61.79

EF 0 40.17 12.6 5.04 57.81

FG 0 25.22 12.6 5.04 42.86

GH 0 20.7 12.6 5.04 38.34

IJ 34 21.2 12.6 5.04 72.84

JK 34 21.2 12.6 5.04 72.84

KL 44.15 21.2 12.6 5.04 82.99

LM 40.17 21.2 12.6 5.04 79.01

MN 25.22 21.2 12.6 5.04 64.06

NN1 25.22 21.2 12.6 5.04 64.06

OP 21.2 34 12.6 5.04 72.84

PQ 21.2 44.15 12.6 5.04 82.99

QR 21.2 44.15 12.6 5.04 82.99

RS 21.2 44.15 12.6 5.04 82.99

ST 21.2 44.15 12.6 5.04 82.99

TT1 49.35 44.15 12.6 5.04 111.14

UV 34 0 12.6 5.04 51.64

VW 44.15 0 12.6 5.04 61.79

Table 1 : Total slap load for each beam

Beam

designation

Slap load Wall load

KN/M2

Beam self

weight

KN/M2

Total load

KN/M2LHS

KN/M2

RHS

KN/M2

AI 0 34 12.6 5.04 51.64

IO 0 0 12.6 5.04 17.64

OU 0 43 12.6 5.04 60.64

GG1 31.4 27.13 12.6 5.04 76.17

HH1 27.13 0 12.6 5.04 44.77

G1H1 49.35 20.7 12.6 5.04 87.69

H1T 0 0 12.6 5.04 17.64

TZ 35.34 0 12.6 5.04 52.98

G1T1 31.4 0 12.6 5.04 49.04

BJ 43 43 12.6 5.04 103.64

CK 43 43 12.6 5.04 103.64

DL 43 35.34 12.6 5.04 95.98

EM 35.34 35.34 12.6 5.04 88.32

FN 35.34 31.4 12.6 5.04 84.38

PV 43 35.34 12.6 5.04 95.98

QW 35.34 35.34 12.6 5.04 88.32

RX 35.34 35.34 12.6 5.04 88.32

WX 44.15 0 12.6 5.04 61.79

XY 44.15 0 12.6 5.04 61.79

YZ 44.15 0 12.6 5.04 61.79

Go to staad

Bar

size

(mm)

Number of bars

1 2 3 4 5 6 7 8 9 10

6 28.3 56.6 84.9 113 142 170 198 226 255 283

8 50.3 101 151 201 252 302 352 402 453 503

10 78.5 157 236 314 393 471 550 628 707 785

12 113 226 339 452 566 679 792 905 1020 1130

16 201 402 603 804 1010 1210 1410 1610 1810 2010

20 314 628 943 1260 1570 1890 2200 2510 2830 3140

25 491 982 1470 1960 2450 2950 3440 3930 4420 4910

32 804 1610 2410 3220 4020 4830 5630 6430 7240 8040

40 1260 2510 3770 5030 6280 7540 8800 10100 11300 12600

Table 3.5: Cross-sectional areas of bars (mm2)

.

LinksBottom Extra

0.7L

Top Extra

0.25L

Bottom

Bars

Top BarsSize

mm

Beam

Name8Ø@150 C/c 1 T 162 T 252 T 162 T 32600X250AB

8Ø@171C/c1 T 162 T 202 T 162 T 25600X250BC8Ø@166C/c1 T 162 T 252 T 122 T 32600X250CD

10Ø@150C/c1 T 252 T 252 T 162 T 32800X250DE8Ø@146C/c1 T 202 T 252 T 162 T 32800X250EF8Ø@223C/c1 T 82 T 122 T 82 T 16600X250FG8Ø@216C/c1 T 102 T 82 T 82 T 10450X250GH

10Ø@150C/c1 T 162 T 252 T 162 T 32600X250IJ10Ø@120C/c1 T 162 T 202 T 162 T 25600X250JK8Ø@100 C/c1 T 162 T 252 T 162 T 32600X250KL

10Ø@120C/c1 T 402 T 252 T 322 T 32800X250LM8Ø@163C/c1 T 202 T 252 T 202 T 32800X250MN

NN18Ø@109C/c1 T 252 T 202 T 162 T 25600X250OP

10Ø@120C/c1 T 402 T 252 T 322 T 32800X250PQ8Ø@66C/c1 T 252 T 252 T 252 T 32800X250QR

10Ø@120C/c1 T 322 T 252 T 252 T 32800X250RS10Ø@120C/c1 T 202 T 202 T 202 T 25600X250ST10Ø@120C/c1 T 122 T 202 T 102 T 25450X250TT1

8Ø@160C/c1 T 162 T 252 T 162 T 32600X250UV8Ø@110C/c1 T 252 T 252 T 252 T 32800X250VW8Ø@103C/c1 T 202 T 252 T 202 T 32800X250WX8Ø@103C/c1 T 202 T 252 T 202 T 32800X250XY

Table : bars of steel for beam

.

LinksBottom Extra

0.7L

Top Extra

0.25L

Bottom

Bars

Top BarsSize

Mm

Beam

Name8Ø@104C/c1 T 252 T 202 T 252 T 25600X250AI

10Ø@120 C/c1T162T202T202T25450X250IO10Ø@120C/c1 T 252 T 202 T 252 T 25600X250OU

8Ø@168C/c1 T 162 T 202 T 162 T 25450X250G G18Ø@116C/c1 T 162 T 122 T 122 T 16450X250H H18Ø@218C/c1 T 122 T 102 T 122 T 10450X250G1 H1

10Ø@120C/c1 T 102 T 162 T 82 T 16450X250H1 T10Ø@120C/c1 T 252 T 162 T 202 T 20600X250TZ10Ø@120C/c1 T 162 T 202 T 162 T 25600X250G1 T110Ø@120C/c1 T 402 T 252 T 322 T 32600X250BJ10Ø@120C/c1 T 402 T 252 T 322 T 32600X250CK10Ø@120C/c1 T 252 T 252 T 252 T 32600X250DL10Ø@120C/c1 T 252 T 252 T 252 T 32600X250EM10Ø@120C/c1 T 252 T 252 T 252 T 32600X250FN8Ø@120 C/c1 T 322 T 252 T 252 T 32600X250PV

8Ø@64C/c1 T 252 T 252 T 252 T 32600X250QW10Ø@120C/c1 T 252 T 252 T 252 T 32600X250RX10Ø@120C/c1 T 252 T 252 T 252 T 32600X250SY

Bar

size

(mm)

Number of bars

1 2 3 4 5 6 7 8 9 10

6 28.3 56.6 84.9 113 142 170 198 226 255 283

8 50.3 101 151 201 252 302 352 402 453 503

10 78.5 157 236 314 393 471 550 628 707 785

12 113 226 339 452 566 679 792 905 1020 1130

16 201 402 603 804 1010 1210 1410 1610 1810 2010

20 314 628 943 1260 1570 1890 2200 2510 2830 3140

25 491 982 1470 1960 2450 2950 3440 3930 4420 4910

32 804 1610 2410 3220 4020 4830 5630 6430 7240 8040

40 1260 2510 3770 5030 6280 7540 8800 10100 11300 12600

Table 3.5: Cross-sectional areas of bars (mm2)

LinksNO. of

Bars

SizeMM

Column

Name8T @ 150 c/cT 16 6600mm X 250mmA

8T @ 150 c/cT 16 8250mm X 600mmB

8T @ 150 c/cT 16 4250mm X 600mmC

8T @ 150 c/cT 16 8250mm X 600mmD

8T @ 150 c/cT 16 8250mm X 600mmE

8T @ 150 c/cT 16 4250mm X 600mmF

8T @ 150 c/cT 16 4250mm X 600mmG

8T @ 150 c/cT 16 4250mm X 600mmG1

8T @ 150 c/cT 16 4250mm X 600mmH

8T @ 150 c/cT 16 4250mm X 600mmH1

8T @ 150 c/cT 16 4600mm X 250mmI

8T @ 150 c/cT 25 6600mm X 250mmJ

8T @ 150 c/cT 20 4250mm X 600mmK

8T @ 150 c/cT 20 8250mm X 600mmL

8T @ 150 c/cT 20 8250mm X 600mmM

8T @ 150 c/cT 20 4250mm X 600mmN

8T @ 150 c/cT 16 4600mm X 250mmO

8T @ 150 c/cT 20 8250mm X 600mmP

Table : bars of steel for column

LinksNO. of

bars

SizeMM

Column

Name8T @ 150 c/cT 20 8250mm X 600mmQ

8T @ 150 c/cT 20 8250mm X 600mmR

8T @ 150 c/cT 16 4250mm X 600mmS

8T @ 150 c/cT 16 4600mm X 250mmT

8T @ 150 c/cT 16 4250mm X 600mmT1

8T @ 150 c/cT 16 4250mm X 600mmU

8T @ 150 c/cT 20 6250mm X 600mmV

8T @ 150 c/cT 20 6250mm X 600mmW

8T @ 150 c/cT 25 4250mm X 600mmX

8T @ 150 c/cT 20 6250mm X 600mmY

8T @ 150 c/cT 16 8600mm X 250mmZ

STEP 1

Assume overall depth

Lx/d =32

7500/d=32

d= 234 mm

h=d+dia/2+c

h=234+12/12+20=260 mm

STEP 2: LOADS

DL=GK=1x1x0.26x24+1=7.24 KN/m2

L.L=QK=2.5 KN/m2

Design load =1.4GK+1.6QK

Wu =1.4x7.24+1.6x2.5=14.13 KN

STEP3: bending moment max

Msx=B Wu Lx

= -0.068x14.13x7.22

= -54 KNm

Msy= -0.037x14.13x7.22

= -29.4 KNm

STEP 4: moment of resistance of

c/r

Mu=0.156fcu b d2

=0.156x30x2342

= 256.2x106 Nmm

=256.2 KNm

STEP 5

Mu > M

256.2 > 54 yes ok S.R slab

STEP 6 Equation of Design

For shorten Direction K=M/fcubd2

=54x106/30x1000x2342

= 0.03

Z=d(0.5+Squroot 0.25+k/0.9)

=234(0.5+Squroot 0.25+0.03/0.9)

=225.9 mm < 0.95d = 0.95x234

=222 mm NOT OK

Z=222 mm

As=M/0.95fyZ

=54x106/0.95x460x222

=556 mm2 provide 12 T@200 c/c _ 566

mm2

Check for As min and As maxAs max = 4/100 x b x h

= 4/100 x 1000 x 260 = 10400 mm2

As min = 0.4/100 x b x h

= 0.13/100 x 1000 x 260 =338 mm2

For longer Direction K=M/fcubd2

=29.4x106/30x1000x2342= 0.017

Z=d(0.5+Squroot 0.25+k/0.9)

=234(0.5+Squroot 0.25+0.017/0.9)

=229 mm < 0.95d = 0.95x234

=222 mm NOT OK

Z=222 mm

As=M/0.95fyZ

=29.4x10^6/0.95x460x222

=303 mm2 provide 10 T@200 c/c _ 393

mm2

Check for As min and As max As max = 4/100 x b x h

= 4/100 x 1000 x 260 = 10400 mm2

As min = 0.4/100 x b x h

= 0.13/100 x 1000 x 260 =338 mm2

Bar

Size

(mm)

Spacing of bars

50 75 100 125 150 175 200 250 300

6 566 377 283 226 189 162 142 113 94.3

8 1010 671 503 402 335 287 252 201 168

10 1570 1050 785 628 523 449 393 314 262

12 2260 1510 1130 905 754 646 566 452 377

16 4020 2680 2010 1610 1340 1150 1010 804 670

20 6280 4190 3140 2510 2090 1800 1570 1260 1050

25 9820 6550 4910 3930 3270 2810 2450 1960 1640

32 16100 10700 8040 6430 5360 4600 4020 3220 2680

40 25100 16800 12600 10100 8380 7180 6280 5030 4190

Table 3.15: Cross-sectional area per meter width (mm2) Slabs

Long side reinforceme

nt

Short side reinforceme

nt

Overall depthmm

Slab sizemm

Slab name

10T@200C/C12T@200 C/C2341O604 X 7500S1

8T@175C/C10T@200C/C2347203 x7500S2

10T@200C/C10T@200C/C2347203 x7500S3

10T@200C/C12T@175C/C23410604 x 7500S4

10T@200C/C12T@200C/C2348804 x 7500S5