Performance of High-Rise Steel Building With and Without Bracings
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This document presents a comparative study on the performance of high-rise steel buildings with and without bracings, focusing on how these structures respond to gravity, wind, and earthquake loads. Utilizing STAAD.Pro software, a 20-storey steel frame model is developed, with analyses conducted for various bracing configurations and loading conditions across different seismic zones. Key findings indicate that incorporating bracings significantly impacts node displacements, particularly under wind loads, enhancing the structural stability of the building.
![G.Hymavathi et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 11, (Part - 4) November 2015, pp.103-114
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PERFORMANCE OF EQ EFFECT BUILDING
ON AXIAL FORCE IN FIGURES
The earth quake effect that Axial Force in the
exterior columns in un braced structure are Zone II
and Zone V are same. No significant variation is
found in the interior column.
The earth quake effect that Axial Force in the
exterior columns in braced structure are Zone II and
Zone V are same. No significant variation is found in
the interior column.
Conclusions of building on nodal displacements
Zone II the wind effect that nodal displacements
in the exterior columns in braced structure and un
braced structure nodal displacement is varied, the un
braced structure the displacement is more compared
with braced structure at top of building 25% No
significant variation in interior column also.
Zone II the earth quake effect that nodal
displacements in the exterior and interior columns in
braced structure and un braced structure nodal
displacement is increased gradually up to certain
height and then decreased gradually from top level. In
the un braced structure the displacement is more
compared with braced structure, at top of building
almost same braced and un braced structure.
Zone V the earth quake effect that nodal
displacements in the exterior and interior columns in
braced structure and un braced structure nodal
displacement is increased gradually from top level. In
the un braced structure the displacement is more
compared with braced structure, at top of building
varied 23% braced and un braced structure.
The Earth quake effect that nodal displacements
in the exterior and interior columns in braced and un
braced structure are Zone II is low when compared
with Zone V. The variation is linearly from bottom
to top level for both earth quake zones, at the bottom
to top maximum variation is 75% and for both.
Conclusions of building on axial force
The Wind effect that Axial Force the exterior
columns in braced structure are low when
compared with un braced structure, from top floor
both are same. No significant variation is found in the
interior column.
Zone II and Zone V earth quake effect that axial
force the exterior columns in braced structure are
low when compared with un braced structure, from
top floor both are same. In the interior columns
almost same in braced and un braced structures
The variation of Zone II and Zone V the earth
quake effect that Axial Force in the exterior columns
in braced and un braced structure are same. No
significant variation is found in the interior column.
Discussions
In high rise buildings the stability can be achieved
by suitably adding the dimensions of the external
columns with diagonal X-bracings. Provision of X-
bracings reduces the amount of displacements in
structure.
In case of any reasons Zone provision will be
changed the bracings can also be used as a retrofitting
technique to strengthen the existing structure as X-
bracings will act more like shear wall.
The braced building of the storey displacement
decreases as compared to the un braced building
which indicates that the overall response of the
building decreases.
The displacement of the building decreases depending
upon the different bracing system employed and the
bracing sizes, about the whole of performance of X
braced building better than the other braced building.
Scope for Further Work
The present work is an approach to carry out
initial study the response of very large complicated
tall structures. The work may be extended to aspects
like condition monitoring of these structures due to
moments and time period of earth quake motions. The
following challenging case studies can be taken up
with recent developments in finite element analysis
and sap software.
References
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and BS 5950-1:2000. Structural Engineer.
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[2.] B. Dean Kumar, B. L. P. Swami, Y. Balakoti
Reddy, (2011), Appropriate Design Wind
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[5.] Bush T. D., Jones E. A. and Jirsa J. O.,
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![G.Hymavathi et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 11, (Part - 4) November 2015, pp.103-114
www.ijera.com 114 | P a g e
Computers and Structures Volume 29 No.4, pp
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Performance of High-Rise Steel Building With and Without Bracings
- 1. G.Hymavathi et al. Int. Journal of Engineering Research and Applications www.ijera.com ISSN: 2248-9622, Vol. 5, Issue 11, (Part - 4) November 2015, pp.103-114 www.ijera.com 103 | P a g e Performance of High-Rise Steel Building With and Without Bracings G.Hymavathi, B. Kranthi Kumar, N.Vidya Sagar Lal 1 P.G. Student, Department of Civil Engineering, Gokul institute of technology, piridi, bobbili, viziana garam, Andhra Pradesh, India 2 Assistant Professor, Department of Civil Engineering, Sistam college,ampolu road ,srikakulam,Andhra Pradesh, India , 3 Assistant professor, department of civil engineering, gokul institute of technology, piridi, bobbili, vizianagaram, Andhra Pradesh, India. Abstract A comparative study on performance of high-rise steel building with and without bracings, carried out on a residential building by considering the gravity loads and lateral loads in the form of Earth quake loads and Wind loads incorporating the Bracings to reduce lateral loads on structural elements. In this study, a 20 storey steel frame structure has been selected to be idealized as multi storey steel building model. The model is analyzed by using STAAD.Pro 2008 structural analysis software with the consideration of wind and earthquake loads. At the same time the influence of X-bracing pattern has been investigated.The building proposed in designed by Limit State Method according to steel code IS: 800-2007, the Wind load analysis according to IS: 875-(part-3)1987 and seismic/Earth quake loads according to IS: 1893 (Part-1)-2002. In this study the node displacements of buildings having with and without bracings of wind and earthquake effect of Zone II and Zone V, and the axial force of the members of the buildings having with and without bracings of wind and earthquake effect of Zone II and Zone V. Keywords: Wind load, Displacement, Axial force, Bracings. I. INTRODUCTION The tallness of a building is relative and cannot be defined in absolute terms either in relation to height or the number of stories. But, from a structural engineer's point of view the tall building or multi- storeyed building can be defined as one that, by virtue of its height, is affected by lateral forces due to wind or earthquake or both to an extent that they play an important role in the structural design. Buildings and structures are considered stable with lateral supports by using either bracing systems or shear system or both such as wall to ensure the stability of the building. Moreover, the important thing to consider are the software to be used for the analysis of tall building structure and wind speed at construction area to avoid any problems in future. One of the problems is affected from wind load. Wind creates inward and outward pressures acting on building surfaces, depending on the orientation of the surface such as flat. This pressure increases uplift on parts of the building, forcing the building apart if it is too weak to resist the wind loads. Therefore, the most important thing to overcome this problem is the connection between beam and column in a frame such as rigid or pin ended should be considered for a realistic design it will become instable structure which means loss of some situation and come close to a failure such as buckling and sway if the structure cannot sustain for a certain load whether from dead load, imposed load, wind load and also natural phenomena like earthquake. II. LITRATURE REVIEW Previous Studies Suresh P, Panduranga Rao B, kalyana Rama J.S, presented a Structures are classified as rigid and flexible. The present investigation deals with the calculation of wind loads using static and gust factor method for a sixteen storey high rise building and results are compared with respect to drift. Structure is analyzed in STAAD Pro, with wind loads calculated by gust factor as per IS 875-Part III with and without X- bracings at all the four corners from bottom to top. Present Study In the present problem the 20 storey building with steel elements as columns and beams, those building outside panels are provided with X - bracings and the interior panels of the building are without bracings are modeled of this problem. The model is prepared using STAAD Pro analysis software. All features like dead load, live load, wind load and seismic load. The loads on various structural components like vertical, horizontal and inclined members are evaluated and the members are designed as per the IS specifications. In Chapter 5 prescribed the node displacements of buildings having with and RESEARCH ARTICLE OPEN ACCESS
- 2. G.Hymavathi et al. Int. Journal of Engineering Research and Applications www.ijera.com ISSN: 2248-9622, Vol. 5, Issue 11, (Part - 4) November 2015, pp.103-114 www.ijera.com 104 | P a g e without bracings of earthquake effect of Zone II and Zone V. Braced Frames Application on braced frames is typically used in which the beam and column are designed resist vertical loads only . Horizontal loads are resisted by bracing element to achieve lateral stability of the structures. The braced framing system able to achieve material savings with respect to moment resisting frame and control of frame drift due to lateral forces. Wind bracing system can be installed as longitudinal bracing or transverse bracing. A building also can be designed for combination of both longitudinal and transverse bracing. There are two types of braced frames which are concentrically braced frames and eccentrically braced frames Concentrically braced frames (CBF) Factors affecting the inelastic cyclic response of a concentrically braced frame including the following The slenderness and compactness of the bracing member. The relative axial strength of the brace in compression and tension. The strength of the brace connections to the beam and columns. The degree of lateral restraint provided to the brace to beam connection. The stiffness, strength, and compactness of the beam into which the brace frames. Design of Wind Pressure: The design wind pressure at any height above mean ground level shall be obtained by the following relationship between wind pressure and wind velocity: Pz = 0.6 Vz2 Where Pz is design wind pressure in N/m2 at height z, and Vz is design wind velocity in m/s at height z, Design of wind speed (Vz) The basic wind speed (Vb) for any site shall be obtained from below figure and shall be modified to include the following effects to get design wind velocity at any height (Vz) for the chosen structure. a. Risk level; b. Terrain roughness height and size of structure; and c. Local topography It can be mathematically expressed as follows; Vz = Vh x K1 x K2 x K3 Where Vz = design wind speed at any height z in m/s; K1 is Probability factor (risk coefficient) K2 is terrain, height and structure size factor K3 is topography factor Note: design wind speed up to 10m height from mean ground level shall be considered constant Design Approach for Braced frames A braced frame is one in which resistance to lateral force and frame instability is provided by a specially designed bracing system. The bracing system in a building frame is designed to serve the following important functions. Resisting lateral loads Counteraction the over turning moment (p-∆ moment ) due to gravity loads Preventing Frame buckling and Improving sway behavior. Earthquake Zone Intensity Zone 5 Zone 5 covers the areas with the highest risks zone that suffers earthquakes of intensity MSK IX or greater. The IS code assigns zone factor of 0.36 for Zone 5. Zone 4 This zone is called the High Damage Risk Zone and covers areas liable to MSK VIII. The IS code assigns zone factor of 0.24 for Zone 4. Zone 3 This zone is classified as Moderate Damage Risk Zone which is liable to MSK VII. and also 7.8 The IS code assigns zone factor of 0.16 for Zone 3. Zone 2 This region is liable to MSK VI or less and is classified as the Low Damage Risk Zone. The IS code assigns zone factor of 0.10 for Zone 2. Load Calculations Loads and load combinations are given as per Indian standards. (IS 875:1984, IS 1893:2002 and IS 800:2007) Gravity Loading Floor load and Dead loads are calculated as per general considerations as per IS 875 part1. (ref Appendix 3&4) Live load – 2.5kN/m2 Wind Loading Static wind load is given as per IS 875-Part
- 3. G.Hymavathi et al. Int. Journal of Engineering Research and Applications www.ijera.com ISSN: 2248-9622, Vol. 5, Issue 11, (Part - 4) November 2015, pp.103-114 www.ijera.com 105 | P a g e III According to IS CODE (875 PART 3), Vz = Vb×K1×K2×K3 Pz is Design wind pressure at a height z meter. Pz =0.6Vz 2 The following assumptions are taken for the wind load calculation Location – Visakhapatnam Wind speed – 50m/s (ref Appendix 5) Terrain category – 3 and Class – C K1 – 1.08 (life- 100 years) K2 – depending upon the variation of height K3 – 1.00 (flat topography) Dynamic wind load also calculated by using gust factor approach ANALYSIS FOR G+20 BUILDING: Along X – Direction: Regional wind speed (Vb) = 50 m/sec Risk coefficient factor (K1) = 1.08 (ref. sec 3.3.3) Topography factor (K3) = 1 (ref. sec 3.3.3) Design wind speed (Vz) = k1*k2*k3*Vb = 54*k2 Width of the building along wind (a)=X(a) = 48 m Width of the building normal wind(b)=Y(b)=44 m Height (h) above G.L = 77 m a/b = 1.09 h/b = 1.75 Cf = 1.2 (ref fig.2 in Appendix) For Wind force at level 10 m for G+20 building at node 1 along X-direction is Area (A)= 3.5 m2 Pressure (Pz)= 0.6 Vz2 = 0.6 X 50 K2 = 0.6 X 50 X 0.99 = 1.72 kN/m2 Wind Force (F)=A* Cf* Pz= 3.5x1.2x1.72 = 7.22 kN Seismic loading: - Seismic load is given as per IS 1893- 2002. Following assumptions are used for the calculation. Zone factor – 0.1 (Zone-2) – 0.36(Zone-5) Importance Factor – 1.5 Soil type – 2 (medium Soil) Structure type –Steel Frame Building Damping co-efficient – 5% Response reduction – 4 (for concentric brace) 5 (for eccentric brace) 5(Special Moment Resisting Frame (SMRF)
- 4. G.Hymavathi et al. Int. Journal of Engineering Research and Applications www.ijera.com ISSN: 2248-9622, Vol. 5, Issue 11, (Part - 4) November 2015, pp.103-114 www.ijera.com 106 | P a g e NODAL DISPLACEMENTS IN WITHOUT AND WITH BRACINGS Zone ii variation of node displacements and heights for external column in x- direction (without and with bracings wind load) Nodal Displacements Loading (Dead + Live + wind) Node Height Without Bracings With Bracings No. (m) (mm) (mm) 0008 0.0 0.000 0.000 1008 3.5 104.859 92.817 2008 7.0 146.242 126.187 3008 10.5 182.294 153.600 4008 14.0 219.413 180.078 5008 17.5 273.626 219.513 6008 21.0 330.023 259.413 7008 24.5 383.237 296.570 8008 28.0 433.070 331.108 9008 31.5 479.705 363.294 10008 35.0 523.029 393.155 11008 38.5 563.214 420.894 12008 42.0 600.418 446.705 13008 45.5 634.772 470.74 14008 49.0 666.384 493.124 15008 52.5 695.327 513.916 16008 56.0 721.339 532.915 17008 59.5 744.476 550.144 18008 63.0 764.816 565.653 19008 66.5 782.442 579.466 20008 70.0 797.460 591.566 21008 73.5 809.922 601.938 22008 77.0 820.552 -610.212 Zone ii variation of node displacements and heights for interior column in x- direction (without and with bracings wind load Nodal Displacements Loading (Dead + Live + wind) Node Height Without Bracings With Bracings No. (m) (mm) (mm) 0008 0.0 0.000 0.000 1008 3.5 104.859 92.817 2008 7.0 146.242 126.187 3008 10.5 182.294 153.600 4008 14.0 219.413 180.078 5008 17.5 273.626 219.513 6008 21.0 330.023 259.413 7008 24.5 383.237 296.570 8008 28.0 433.070 331.108 9008 31.5 479.705 363.294 10008 35.0 523.029 393.155 11008 38.5 563.214 420.894 12008 42.0 600.418 446.705 13008 45.5 634.772 470.74 14008 49.0 666.384 493.124 15008 52.5 695.327 513.916 16008 56.0 721.339 532.915 17008 59.5 744.476 550.144 18008 63.0 764.816 565.653 19008 66.5 782.442 579.466 20008 70.0 797.460 591.566 21008 73.5 809.922 601.938 22008 77.0 820.552 -610.212 0 20 40 60 80 100 0 500 1000 NODE DISPLACEMENTS (mm) Figure 5.1.1 ZONE II VARIATION OF NODE DISPLACEMENTS IN EXTERNAL COLUMN WITH AND WITHOUT WIND LOAD D+L+W X (mm) D+L+W X B (mm)
- 5. G.Hymavathi et al. Int. Journal of Engineering Research and Applications www.ijera.com ISSN: 2248-9622, Vol. 5, Issue 11, (Part - 4) November 2015, pp.103-114 www.ijera.com 107 | P a g e PERFORMANCE OF WIND EFFECT BUILDING ON NODAL DISPLACEMENTS IN FIGURES the wind effect that nodal displacements in the exterior columns in X-direction braced structure and un braced structure are almost same up to 14 m height, from this point the braced structure nodal displacement is varied, the un braced structure the displacement is more compared with braced structure at top of building 25.52% and peak displacement at 56m height of building noted. No significant variation in interior column also. Zone ii and zone v variation of node displacements and heights for external column in x- direction (without bracings) Nodal Displacements Loading (Dead + Live + EQ) Node Height Without Bracings Zone II Without Bracings Zone V No. (m) (mm) (mm) 0008 0.0 0.000 0.000 1008 3.5 1.029 3.853 2008 7.0 1.589 5.540 3008 10.5 2.006 6.983 4008 14.0 2.370 8.376 5008 17.5 2.583 9.731 6008 21.0 3.106 11.438 7008 24.5 3.654 13.167 8008 28.0 4.202 14.887 9008 31.5 4.747 16.591 10008 35.0 5.286 18.270 11008 38.5 5.816 19.917 12008 42.0 6.338 21.523 13008 45.5 6.848 23.081 14008 49.0 7.346 24.581 15008 52.5 7.834 26.017 16008 56.0 8.314 27.384 17008 59.5 8.791 28.677 18008 63.0 9.276 29.899 19008 66.5 9.786 31.057 20008 70.0 10.359 32.180 21008 73.5 10.973 33.236 22008 77.0 12.114 34.709 Zone ii and zone v variation of node displacements and heights for internal column in x- direction (without bracings) Nodal Displacements Loading (Dead + Live + EQ) Node Height Without Bracings Zone II Without Bracings Zone V No. (m) (mm) (mm) 0008 0.0 0.000 0.000 1008 3.5 1.029 3.853 2008 7.0 1.589 5.540 3008 10.5 2.006 6.983 4008 14.0 2.370 8.376 5008 17.5 2.583 9.731 6008 21.0 3.106 11.438 0 10 20 30 40 50 60 70 80 90 0 500 1000 HEIGHT(m) NODE DISPLACEMENTS (mm) ZONE II VARIATION OF NODE DISPLACEMENTS IN INTERNAL COLOUMN WITH AND WITHOUT WIND LOAD D+L+W X (mm) D+L+W X B (mm) 0 10 20 30 40 50 60 70 80 90 0 20 40 HEIGHT(m) NODE DISPLACEMENTS (mm) ZONE II & ZONE V VARATION OF NODE DISPLACEMENTS EXTERNAL COLUMN WITH OUT BRACINGS IN EQ LOAD D+L+E Z2 X (mm) D+L+E Z5 X (mm)
- 6. G.Hymavathi et al. Int. Journal of Engineering Research and Applications www.ijera.com ISSN: 2248-9622, Vol. 5, Issue 11, (Part - 4) November 2015, pp.103-114 www.ijera.com 108 | P a g e 7008 24.5 3.654 13.167 8008 28.0 4.202 14.887 9008 31.5 4.747 16.591 10008 35.0 5.286 18.270 11008 38.5 5.816 19.917 12008 42.0 6.338 21.523 13008 45.5 6.848 23.081 14008 49.0 7.346 24.581 15008 52.5 7.834 26.017 16008 56.0 8.314 27.384 17008 59.5 8.791 28.677 18008 63.0 9.276 29.899 19008 66.5 9.786 31.057 20008 70.0 10.359 32.180 21008 73.5 10.973 33.236 22008 77.0 12.114 34.709 PERFORMANCE OF EQ EFFECT BUILDING ON NODAL DISPLACEMENTS IN WITHOUT BRACING FIGURES The Earth quake effect that nodal displacements in the exterior columns in X-direction un braced structure are Zone II is low when compared with Zone V. The variation is linearly from bottom to top level for both earth quake zones, at the bottom and top variation is 73.29% and 65% and for both conditions the peak variation is at 21m height. The Earth quake effect that nodal displacements in the interior columns in X-direction un braced structure are Zone II is low when compared with Zone V. The variation is linearly from bottom to top level for both earth quake zones at the bottom and top variation is 71.52% and 65.91% and for both conditions the peak variation is at 21m height Zone ii and zone v variation of node displacements and heights for external column in x- direction (with bracings) Nodal Displacements Loading (Dead + Live + EQ) Node Height Without Bracings Zone II Without Bracings Zone V No. (m) (mm) (mm) 0008 0.0 0.000 0.000 1008 3.5 1.029 3.853 2008 7.0 1.589 5.540 3008 10.5 2.006 6.983 4008 14.0 2.370 8.376 5008 17.5 2.583 9.731 6008 21.0 3.106 11.438 7008 24.5 3.654 13.167 8008 28.0 4.202 14.887 9008 31.5 4.747 16.591 10008 35.0 5.286 18.270 11008 38.5 5.816 19.917 12008 42.0 6.338 21.523 13008 45.5 6.848 23.081 14008 49.0 7.346 24.581 15008 52.5 7.834 26.017 16008 56.0 8.314 27.384 17008 59.5 8.791 28.677 18008 63.0 9.276 29.899 19008 66.5 9.786 31.057 20008 70.0 10.359 32.180 21008 73.5 10.973 33.236 22008 77.0 12.114 34.709 0 10 20 30 40 50 60 70 80 90 0 20 40 HEIGHT(m) NODE DISPLACEMENTS (mm) ZONE II & ZONE V VARATION OF NODE DISPLACEMENTS INTERNAL COLUMN WITHOUT BRACINGS IN EQ LOAD D+L+E X Z2 (mm) D+L+E X Z5 (mm)
- 7. G.Hymavathi et al. Int. Journal of Engineering Research and Applications www.ijera.com ISSN: 2248-9622, Vol. 5, Issue 11, (Part - 4) November 2015, pp.103-114 www.ijera.com 109 | P a g e Zone ii and zone v variation of node displacements and heights for internal column in x- direction (with bracings) Nodal Displacements Loading (Dead + Live + EQ) Node Height With Bracings Zone II With Bracings Zone V No. (m) (mm) (mm) 62 0.0 0.000 0.000 1062 3.5 0.862 2.679 2062 7.0 1.219 3.697 3062 10.5 1.507 4.549 4062 14.0 1.695 5.291 5062 17.5 1.118 5.338 6062 21.0 0.980 5.849 7062 24.5 1.007 6.523 8062 28.0 1.171 7.330 9062 31.5 1.442 8.239 10062 35.0 1.798 9.228 11062 38.5 2.228 10.283 12062 42.0 2.724 11.391 13062 45.5 3.281 12.547 14062 49.0 3.901 13.746 15062 52.5 4.588 14.989 16062 56.0 5.350 16.279 17062 59.5 6.204 17.627 18062 63.0 7.172 19.049 19062 66.5 8.291 20.574 20062 70.0 9.613 22.243 21062 73.5 11.262 24.170 22062 77.0 13.072 26.171 0 10 20 30 40 50 60 70 80 90 0 20 40 HEIGHT(m) NODE DISPLACEMENTS (mm) ZONE II & ZONE V VARATION OF NODE DISPLACEMENTS EXTERNAL COLUMN WITH BRACINGS IN EQ LOAD D+L+E Z2 X B (mm) D+L+E Z5 X B (mm)
- 8. G.Hymavathi et al. Int. Journal of Engineering Research and Applications www.ijera.com ISSN: 2248-9622, Vol. 5, Issue 11, (Part - 4) November 2015, pp.103-114 www.ijera.com 110 | P a g e PERFORMANCE OF EQ EFFECT BUILDING ON NODAL DISPLACEMENTS IN WITH BRACING FIGURES The Earth quake effect that node displacements in the exterior columns in X-direction braced structure are Zone II is low when compared with Zone V. The variation is parabolic from bottom to top level, at bottom and top variation is 70.83% and 65.91% and for both conditions the peak variation is at 24.5m height. The Earth quake effect that node displacements in the interior columns in X-direction braced structure are Zone II is low when compared with Zone V. The variation is parabolic from bottom to top level, at bottom and top variation is 67.80% and 50.05% and for both conditions the peak variation is at 24.5m height. PERFORMANCE OF EQ EFFECT BUILDING ON AXIAL FORCE IN FIGURES Zone II the earth quake effect that Axial Force the exterior and interior columns in X-direction braced structure and un braced structure is varied from bottom to top level .The un braced structure axial force is more compared with braced structure. The exterior column axial force at top of building 5.96% and bottom of building 14.84% and peak axial force at 24.5m height of building noted and the interior column axial force at top to bottom level of building almost same and peak axial force at 38.5m height of building noted. Zone V the earth quake effect that Axial Force the exterior and interior columns in X-direction braced structure and un braced structure is varied from bottom to top level .The un braced structure axial force is more compared with braced structure. The exterior column axial force at top of building 5.89% and bottom of building 14.96% and peak axial force at 3.5m height of building noted and the interior column axial force at top to bottom level of building almost same and peak axial force at 28m height of building noted. Zone ii and zone v variation of axial force and heights for external column in x- direction (with out bracings) Axial Force Loading (Dead + Live + EQ) Beam Height Without Bracings With Bracings No. (m) (KN) (KN) 39061 3.5 2540.000 2160.000 40061 7.0 2420.000 2080.000 41061 10.5 2310.000 1990.000 42061 14.0 2190.000 1900.000 43061 17.5 2080.000 1800.000 44061 21.0 1970.000 1710.000 45061 24.5 1850.000 1610.000 46061 28.0 1740.000 1520.000 47061 31.5 1620.000 1420.000 48061 35.0 1510.000 1330.000 49061 38.5 1390.000 1230.000 50061 42.0 1270.000 1130.000 60061 45.5 1160.000 1030.000 70061 49.0 1040.000 926.330 80061 52.5 927.060 824.230 90061 56.0 811.060 721.540 100061 59.5 694.910 618.430 110061 63.0 578.610 515.170 120061 66.5 462.170 412.170 130061 70.0 345.600 310.000 140061 73.5 229.070 209.230 150061 77.0 111.670 105.084 0 10 20 30 40 50 60 70 80 90 0 20 40 HEIGHT(m) NODE DISPLACEMENTS (mm) ZONE II & ZONE V VARATION OF NODE DISPLACEMENTS INTERNAL COLUMN WITH BRACINGS IN EQ LOAD D+L+E Z2 X B (mm) D+L+E Z5 X B (mm)
- 9. G.Hymavathi et al. Int. Journal of Engineering Research and Applications www.ijera.com ISSN: 2248-9622, Vol. 5, Issue 11, (Part - 4) November 2015, pp.103-114 www.ijera.com 111 | P a g e Zone ii and zone v variation of axial force and heights for internal column in x- direction (with out bracings) Axial Force Loading (Dead + Live + EQ) Beam Height Without Bracings With Bracings No. (m) (KN) (KN) 39061 3.5 2540.000 2160.000 40061 7.0 2420.000 2080.000 41061 10.5 2310.000 1990.000 42061 14.0 2190.000 1900.000 43061 17.5 2080.000 1800.000 44061 21.0 1970.000 1710.000 45061 24.5 1850.000 1610.000 46061 28.0 1740.000 1520.000 47061 31.5 1620.000 1420.000 48061 35.0 1510.000 1330.000 49061 38.5 1390.000 1230.000 50061 42.0 1270.000 1130.000 60061 45.5 1160.000 1030.000 70061 49.0 1040.000 926.330 80061 52.5 927.060 824.230 90061 56.0 811.060 721.540 100061 59.5 694.910 618.430 110061 63.0 578.610 515.170 120061 66.5 462.170 412.170 130061 70.0 345.600 310.000 140061 73.5 229.070 209.230 150061 77.0 111.670 105.084 0 10 20 30 40 50 60 70 80 90 0 500 10001500200025003000 HEIGHT(m) AXIAL LOAD (kN) ZONE II & ZONE V VARIATION OF AXIAL LOAD WITHOUT BRACINGS IN EQ LOAD D+L+E Z2 Fx (kN) D+L+E Z5 Fx (kN) 0 10 20 30 40 50 60 70 80 90 0 2000 4000 HEIGHT(m) AXIAL FORCE (kN) ZONE II & ZONE V VARIATION OF AXIAL FORCE WITHOUT BRACINGS IN EQ LOAD D+L+E Z2 Fx (kN) D+L+E Z5 Fx (kN)
- 10. G.Hymavathi et al. Int. Journal of Engineering Research and Applications www.ijera.com ISSN: 2248-9622, Vol. 5, Issue 11, (Part - 4) November 2015, pp.103-114 www.ijera.com 112 | P a g e Zone ii and zone v variation of axial force and heights for external column in x- direction (with bracings) Axial Force Loading (Dead + Live + EQ) Beam Height Without Bracings With Bracings No. (m) (KN) (KN) 39061 3.5 2540.000 2160.000 40061 7.0 2420.000 2080.000 41061 10.5 2310.000 1990.000 42061 14.0 2190.000 1900.000 43061 17.5 2080.000 1800.000 44061 21.0 1970.000 1710.000 45061 24.5 1850.000 1610.000 46061 28.0 1740.000 1520.000 47061 31.5 1620.000 1420.000 48061 35.0 1510.000 1330.000 49061 38.5 1390.000 1230.000 50061 42.0 1270.000 1130.000 60061 45.5 1160.000 1030.000 70061 49.0 1040.000 926.330 80061 52.5 927.060 824.230 90061 56.0 811.060 721.540 100061 59.5 694.910 618.430 110061 63.0 578.610 515.170 120061 66.5 462.170 412.170 130061 70.0 345.600 310.000 140061 73.5 229.070 209.230 150061 77.0 111.670 105.084 Zone ii and zone variation of axial force and heights for internal column in x- direction (with bracings Axial Force Loading (Dead + Live + EQ) Beam Height Without Bracings Zone II Without Bracings Zone V No. (m) (KN) (KN) 39065 3.5 3400.000 3400.000 40065 7.0 3200.000 3200.000 41065 10.5 3010.000 3010.000 42065 14.0 2820.000 2820.000 43065 17.5 2640.000 2640.000 44065 21.0 2470.000 2470.000 45065 24.5 2300.000 2300.000 46065 28.0 2140.000 2140.000 47065 31.5 1990.000 1990.000 48065 35.0 1830.000 1830.000 49065 38.5 1680.000 1680.000 50065 42.0 1540.000 1540.000 60065 45.5 1390.000 1390.000 70065 49.0 1250.000 1250.000 80065 52.5 1110.000 1110.000 90065 56.0 966.245 966.380 100065 59.5 827.743 827.890 110065 63.0 690.345 690.500 12065 66.5 553.898 554.060 13065 70.0 418.319 418.480 14065 73.5 283.338 283.480 15065 77.0 151.023 151.210 0 10 20 30 40 50 60 70 80 90 0 1000 2000 3000 HEIGHT(m) AXIAL FORCE (kN) ZONE II & ZONE V VARATION OF AXIAL FORCE WITH BRACINGS IN EQ LOAD D+L+E Z2 Fx B (kN) D+L+E Z5 Fx B (kN) 0 10 20 30 40 50 60 70 80 90 0 2000 4000 HEIGHT(m) AXIAL FORCE (kN) ZONE II & ZONE V VARIATION OF AXIAL FORCE WITH BRACINGS IN EQ LOAD D+L+E Z2 Fx (kN) D+L+E Z5 Fx (kN)
- 11. G.Hymavathi et al. Int. Journal of Engineering Research and Applications www.ijera.com ISSN: 2248-9622, Vol. 5, Issue 11, (Part - 4) November 2015, pp.103-114 www.ijera.com 113 | P a g e PERFORMANCE OF EQ EFFECT BUILDING ON AXIAL FORCE IN FIGURES The earth quake effect that Axial Force in the exterior columns in un braced structure are Zone II and Zone V are same. No significant variation is found in the interior column. The earth quake effect that Axial Force in the exterior columns in braced structure are Zone II and Zone V are same. No significant variation is found in the interior column. Conclusions of building on nodal displacements Zone II the wind effect that nodal displacements in the exterior columns in braced structure and un braced structure nodal displacement is varied, the un braced structure the displacement is more compared with braced structure at top of building 25% No significant variation in interior column also. Zone II the earth quake effect that nodal displacements in the exterior and interior columns in braced structure and un braced structure nodal displacement is increased gradually up to certain height and then decreased gradually from top level. In the un braced structure the displacement is more compared with braced structure, at top of building almost same braced and un braced structure. Zone V the earth quake effect that nodal displacements in the exterior and interior columns in braced structure and un braced structure nodal displacement is increased gradually from top level. In the un braced structure the displacement is more compared with braced structure, at top of building varied 23% braced and un braced structure. The Earth quake effect that nodal displacements in the exterior and interior columns in braced and un braced structure are Zone II is low when compared with Zone V. The variation is linearly from bottom to top level for both earth quake zones, at the bottom to top maximum variation is 75% and for both. Conclusions of building on axial force The Wind effect that Axial Force the exterior columns in braced structure are low when compared with un braced structure, from top floor both are same. No significant variation is found in the interior column. Zone II and Zone V earth quake effect that axial force the exterior columns in braced structure are low when compared with un braced structure, from top floor both are same. In the interior columns almost same in braced and un braced structures The variation of Zone II and Zone V the earth quake effect that Axial Force in the exterior columns in braced and un braced structure are same. No significant variation is found in the interior column. Discussions In high rise buildings the stability can be achieved by suitably adding the dimensions of the external columns with diagonal X-bracings. Provision of X- bracings reduces the amount of displacements in structure. In case of any reasons Zone provision will be changed the bracings can also be used as a retrofitting technique to strengthen the existing structure as X- bracings will act more like shear wall. The braced building of the storey displacement decreases as compared to the un braced building which indicates that the overall response of the building decreases. The displacement of the building decreases depending upon the different bracing system employed and the bracing sizes, about the whole of performance of X braced building better than the other braced building. Scope for Further Work The present work is an approach to carry out initial study the response of very large complicated tall structures. The work may be extended to aspects like condition monitoring of these structures due to moments and time period of earth quake motions. The following challenging case studies can be taken up with recent developments in finite element analysis and sap software. References [1.] Alasdair N.Beal (2006). Columns, sway frames and BS 5950-1:2000. Structural Engineer. Volume (84) : page 40-42 [2.] B. Dean Kumar, B. L. P. Swami, Y. Balakoti Reddy, (2011), Appropriate Design Wind Speeds for Structures, International Journal of Earth Sciences and Engineering, 4(6), pp 504- 507 . [3.] B.S. Krishnamachar, and D. Ajitha Simha (1978). Design of Steel Structures. New Delhi: Tata McGraw-Hill Publishing Company Ltd. [4.] Bungale S. Taranath , Wind and Earthquake resistant buildings: Structural analysis a and design, CRC press, 2nd edition May 2012. [5.] Bush T. D., Jones E. A. and Jirsa J. O., “Behavior of RC frame strengthened using structural steel bracing”, Journal of Structural Engineering, Vol. 117, No.4, April, 1991 [6.] Chen, X. and Kareem, A, (2004), Equivalent static wind loads on buildings: New model, Journal of Structural Engineering, ASCE, 130(10), pp 1425-1435. [7.] Davenport, A. G., (1993), Gust loading factors, Journal of Structural Engineering, ASCE, 93, pp 11–34. [8.] Dennis Lam, Thien-Cheong Ang and Sing- Ping Chiew (2004). Structural Steel Work- Design to Limit State Theory. 3rd edition. Oxford: Elsevier Butterworth-Heinemann. [9.] Desai J. P., Jain A. K. and Arya A. S., “Seismic response of R. C. braced frames”,
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