46

CHAPTER 5

RESULTS AND DISCUSSIONS

5.0 General

The purpose of this study has been to analyze seismic performance of L-shaped building

considering the effect of seismic joint and separation gap. Models of varying bay lengths and

heights for Zone V and response reduction factor 5 are analyzed in this project. For this

study, STAAD.PRO V8i, a linear and non-linear static and dynamic analysis and design

program have been used. Linear static analysis has been performed to know about the

moments, axial forces and displacements. And dynamic analysis (RSM) has been performed

to study about Center of masses, Center of rigidity and torsional moments. In this project the

study is intentionally categorized into three cases.

Case A: Considering separation gap

Case B: Considering seismic joint.

Case C: without separation gap

Numerical models under each case were analysed satisfying the three conditions with respect

to three different bay lengths and four different storied building models for displacements,

axial forces and moments. Under each of the above mentioned conditions the data included in

the models are as follows.

Bay lengths: 4m, 6m.

Number of stories: (G+4) -5 stories, (G+14) -15 stories, (G+24) -25 stories, (G+34) -35

stories.

The response of columns during earthquakes is very important since single column failure

may lead to additional failures and result in total collapses. Hence in this present study we

have concentrated on column responses in terms of shears, axial forces and bending

moments. The selected columns viz., A, B, C, D, E, F, G, H and I are shown in Figure 5.0.

The resulting analysis and discussions are presented in this chapter. The chapter is organised

into results of static and dynamic analysis separately. In static analysis the performance is

measured in terms of displacements, axial forces, bending moments, shears forces and

compared to those cases in the identified columns viz., corner, intermediate and interior. In

dynamic analysis the results in terms of centre of mass, centre of gravity and torsion are

presented.

47

Figure 5.0: Typical Model showing selected columns for Analysis

5.1. Tables representing Static Analysis:

Table 5.1.1 Displacements for 6m bay length

Storey

Displacement for 6m bay in X-direction

With gap Without gap With seismic joint

X Z X Z X Z

5 4.09 4.22 2.89 2.75 2.88 2.67

15 20.57 20.57 15.40 14.45 15.59 14.59

25 49.64 49.69 45.91 41.12 46.40 41.42

35 96.81 97.04 107.66 94.87 107.52 93.77

48

Table 5.1.2 Axial forces for 6m bay length

Column Storey With gap Continuous With joint

A

5 1987.20 2028.27 1984.15

15 7171.91 7838.96 7133.48

25 6376.88 14446.46 12747.28

35 18008.61 17539.48 19245.90

B

5 2052.32 2022.75 2054.15

15 8289.28 7757.80 8312.55

25 7863.42 14168.61 15503.58

35 23127.90 17083.29 21916.33

C

5 3944.92 3959.54 3943.84

15 10480.92 10645.66 10473.70

25 8095.83 17119.94 16738.90

35 22921.59 19763.28 23306.99

D

5 3145.53 3016.54 3155.22

15 10934.28 9845.81 11016.01

25 9259.77 16448.45 18710.75

35 26624.25 19110.23 25355.63

E

5 1954.16 2022.75 1946.76

15 6875.61 7757.80 6833.49

25 6144.38 14168.61 12504.30

35 17177.04 17083.29 19894.23

F

5 3971.50 3975.46 3972.71

15 11027.29 10954.01 11066.32

25 8763.27 17790.35 18234.44

35 25156.48 20635.60 25711.17

G

5 3951.79 3959.54 3952.75

15 10548.43 10645.66 10581.32

25 8266.79 17119.94 17055.60

35 23204.50 19763.28 23990.60

H

5 1977.81 2035.82 1972.43

15 7540.03 8100.85 7534.50

25 7132.25 15232.50 14531.80

35 20886.36 18673.61 22683.25

I

5 1954.16 2028.27 1946.76

15 6875.61 7838.97 6833.55

25 6144.38 14446.46 12508.34

35 17177.04 17539.48 19995.40

49

Table 5.1.3 Bending moments for 6m bay length

Column Storey With gap Continuous With seismic joint

My Mz My Mz My Mz

A

5 144.30 144.36 145.71 146.11 144.16 144.27

15 80.78 81.57 148.08 138.29 80.92 81.73

25 61.97 69.27 183.64 167.91 82.68 93.37

35 91.37 107.35 200.63 181.99 85.45 101.92

B

5 146.47 96.22 145.77 121.90 146.52 96.28

15 83.39 113.30 153.35 137.53 83.40 113.34

25 64.40 69.22 189.59 149.15 88.82 128.01

35 94.00 143.70 206.56 161.28 107.10 134.43

C

5 66.48 72.35 103.32 105.94 66.80 72.56

15 88.27 98.53 145.96 145.73 88.66 98.49

25 65.99 73.12 169.37 168.14 100.55 110.72

35 111.39 130.01 185.44 184.38 108.84 114.82

D

5 66.34 131.29 104.27 127.75 66.86 131.39

15 87.89 122.72 143.00 152.08 88.93 123.05

25 67.20 69.76 164.98 175.43 107.22 126.47

35 110.80 147.81 180.83 186.98 130.93 123.65

E

5 145.88 89.52 145.64 119.92 145.88 89.29

15 80.64 100.33 138.05 133.82 80.67 102.53

25 63.06 68.12 167.95 160.99 82.31 131.93

35 92.47 118.72 182.23 174.66 94.06 189.37

F

5 65.92 75.50 102.82 103.08 66.25 76.29

15 88.25 102.53 129.01 145.31 88.64 102.17

25 65.96 74.17 146.56 168.14 100.52 106.10

35 111.30 133.05 160.78 184.01 108.75 92.76

G

5 67.92 65.25 105.61 102.67 68.45 65.87

15 91.00 86.73 137.34 128.63 91.80 88.64

25 70.28 71.58 157.23 145.81 106.23 117.52

35 116.66 109.98 172.64 159.88 116.92 179.33

H

5 96.69 140.85 118.14 146.19 96.79 140.45

15 104.38 83.93 130.81 148.84 104.36 84.47

25 61.94 70.84 158.48 185.44 112.55 89.63

35 126.30 110.86 172.62 203.18 111.71 94.73

I

5 95.06 89.52 122.13 117.92 95.06 89.29

15 102.68 100.33 138.36 128.76 102.68 102.67

25 63.01 68.12 150.64 154.69 115.61 132.98

35 125.80 118.72 163.23 167.66 127.63 192.75

50

Table 5.1.4 Shear forces for 6m bay length

Column Storey With gap Continuous With seismic joint

Sy Sz Sy Sz Sy Sz

A

5 17.42 79.29 26.54 80.24 17.43 79.21

15 22.80 54.71 53.20 92.01 22.81 54.68

25 25.92 26.21 65.65 112.78 25.95 60.50

35 29.19 61.64 72.74 122.76 28.31 68.43

B

5 81.21 80.68 80.19 80.27 81.26 80.70

15 56.49 56.34 87.56 95.56 56.47 56.46

25 26.71 26.72 105.47 116.79 60.54 59.55

35 64.51 64.66 114.27 127.07 62.09 59.82

C

5 30.71 28.20 45.51 44.03 30.78 28.33

15 40.05 37.13 64.24 49.50 39.98 37.35

25 29.85 28.26 74.30 57.88 43.97 43.13

35 49.34 46.04 80.87 61.74 44.69 49.23

D

5 110.73 29.64 107.48 44.95 110.81 29.83

15 75.60 39.25 105.75 54.71 75.60 39.36

25 29.84 28.96 123.89 61.73 74.99 43.29

35 75.40 48.63 132.31 67.38 73.73 45.51

E

5 76.67 80.31 80.27 80.19 76.45 80.31

15 55.09 55.19 95.56 87.56 56.11 55.20

25 25.66 26.43 116.79 105.47 68.37 57.58

35 63.83 60.50 127.07 114.27 90.27 60.67

F

5 31.89 28.62 44.51 44.51 32.19 28.75

15 41.06 37.15 67.29 67.29 40.78 37.37

25 30.35 28.29 78.75 78.75 41.52 43.15

35 49.82 46.12 85.60 85.60 34.42 49.32

G

5 28.25 29.65 44.03 45.51 28.54 29.88

15 37.64 38.58 49.50 64.24 38.54 38.93

25 29.25 29.09 57.88 74.30 52.66 44.25

35 47.66 47.78 61.74 80.87 78.17 47.05

H

5 18.30 16.40 25.76 25.76 18.49 16.46

15 23.70 21.42 53.77 53.77 23.95 21.49

25 26.67 24.32 66.73 66.73 26.96 24.43

35 30.08 26.49 73.68 73.68 29.24 30.55

I

5 76.67 16.03 80.24 26.54 76.45 16.03

15 55.09 20.78 92.01 53.20 56.16 20.78

25 25.66 23.56 112.78 65.65 68.80 23.62

35 63.83 25.67 122.76 72.74 91.64 25.90