A STUDY ON CONNECTIONS OF MULTISTOREY STEEL FRAME BUILDINGByAditty G BidikarUnder the Guidence of

Dr. S.V. IttiKLESCET BELGAUM

CONTETSINTRODUCTON

SOFTWARES

ANALYSIS AND DESIGN OF COMPONENTS

(BEAMS & COLUMNS)

STEEL FRAME CONNECTIONS

CONNECTION FLEXIBLTY IN FRAMES

RESULTS AND DISCUSSIONS

CONCLUSIONS

INTRODUCTIONDefinition of Multistorey Building

From a structural engineer's point of view the 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 Anatomy of Multistorey Building

The components of a typical steel-framed structure are:BeamsColumnsFloorsBracing SystemsConnections

Generally columns and beams used in the framework are I-sections. The selection of beam sections depends upon the span, loading and limitations on overall depth from headroom considerations. Connections To connect the beams to columns various types of connections are used 1)Simple connections 2)Rigid connections 3)Semi-rigid connections

Thesis ObjectiveTo analyze and design a multistory steel frame building (G+10) with different percentages of rigidities subjected to dead, live and wind loads. The building is analyzed by using the software STAAD Pro-2006 version.

The steel structure is analyzed using various load combinations. About 10 load combinations are used. These load combinations include serviceability load combinations and design load combinations.

The beams and columns are designed using the programs written in excel spreadsheets. The required forces and moments for design are taken from STAAD analysis. Also various connections are designed for beam column joints.

Softwares STAAD.Pro 2006 continues to be the world's most widely-used, customizable and user-friendly structural solutions software. STAAD.Pro 2006 is a combination of a robust 3D multi-material structural modeler with a powerful analysis and design engine capable of solving the most complex linear elastic, soil-structure interaction, dynamics and plastic analysis problems. Around 20,000 structural engineering firms around the world use STAAD-Pro.

STAAD-Pro featuresP-Delta analysis enabled for beams and plates.Linear, P-Delta analysis.Non-linear analysis with automatic load and stiffness correction.Buckling analysis.Full and partial moment releases (excellent for steel frames where releases defined by springs are hard to determine).Fixed, pinned and spring supports with releases. Also Inclined Supports for curved structures.Calculation of steel and concrete quantity

Literature ReviewJ.C.D.HOENDERKAMP and M.C.M.BAKKER

BULENT AKBAS and JAY SHEN

M.SOARES FILHO and M. J. R. GUIMARAES

S. O. DEGERTEKIN and M. S. HAYALIOGLU

Analysis & DesignLOADING(IS:875-1987 PART II)

Occupancy classification Uniformly distributed load (kN/m2) Concentrated load (kN) Offices and Staff roomsClass roomsCorridors, Store rooms and Reading rooms 2.53.04.0 2.72.74.5 ApartmentsRestaurantsCorridors 2.04.03.01.82.74.5

Wind loadWind speed = Vb = 33 m/sVz = Vb x k1 x k2 x k3 (constants k1=k3=1.00)Intensity of wind = Pz = 0.6 Vz2

Height(m) K2 Vz m/s Pz KN/m2 351.03340.6936301.03340.6936250.9832.340.6275200.9832.340.6275150.9431.020.5773100.8829.040.50650.8829.040.506

Load CombinationsDL + LLDL + LL + WXDL + LL + WZDL LL WXDL LL WZ1.5 (DL + LL)1.2 (DL + LL + WX)1.2 (DL + LL +WZ)1.2 (DL + LL WX)1.2 (DL + LL WZ)

Design of beams & columns The beams and columns have been designed as per IS 800 codal provisions. Excel spread sheets have been developed for the design. The beams and columns are designed for rigidities from 0% to 100%.

MethodologyThe building taken for present study is a G+10 steel frame residential building. It has 19m x 15m overall dimensions in plan.The building was modelled in STAAD-Pro according to the architectural plan and section. Various dead, live and wind loads were assigned to the structure and the model was analysed.The analysis results show that beam no. 57 and column no. 17 were critical. Hence these column and beam were taken up for study. STAAD models were made for analysis purpose with rigidities 0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% and 100%. The beam and column were designed for these rigidities. Corresponding bending moment, and shear force were tabulated for beam no 57 and for column 17.The theoretical and practical steel were calculated on the basis of design .Simple, rigid and semi-rigid connections are designed and a study has been done on the variation of steel quantity with respect to different rigidities.

3D view of structure

Loaded Structure

Wind in X direction

Wind in Z direction

Bending moment in structure

Shear force in structure

Table 1 Bending Moments (KNm) in the Beam 57 w.r.t rigidities

Rigid GF 1F 2F 3F 4F 5F 6F 7F 8F 9F 10F 100% 119.2 119.2 117.6113.8111.4114.2112.9111.7110.9108.252.2190% 116.9116.4114.3110.2107.9111.6108.6107.1106.3104.552.480% 112.6111.5111.9110.9106.2106.8105.7104.8103.9100.350.6770% 108.1107.7106.8105.9105.1102.9101.399.998.9698.1448.4660% 104.9101.9101.2100.5100.997.389996.9495.9196.7146.7550% 100.1100.498.7799.2696.42101.7102.8103.5102.7111.350.6540% 109.5110.3110.9109.6106.5110.2112.6110.7111.3118.354.9430% 121.8122.2122.6128.5127.5121.6121.9122.3130.5130.360.9120% 141.9141.1144.6143.6143.4143.8145.9144.4145.7151.470.7710% 167.5167.8166.5170.1169.5169.9170.3171.3170.2172.791.950% 205.8206.4206.5207.7207.2208.4208.4208.4209.8209.8101.5

Graph of Moment v/s Rigidity In Beam

Table 2 Shear Force in the Beam 57 with varying rigidities

RigidGF1F2F3F4F5F6F7F8F9F10F100%119.8114.3115.1116.1116.1114.7112.4110.7115.6115.953.390%120.7115.1116.9117.5116.5114.3114.1115.7115.9115.653.6980%115.6117.3116.3116.3115.8114.8114.8113.5116.8116.353.8670%118.8118.3117.4118.1115.3116.4115112.5114.7118.854.4660%118.9120.8117.2118.6115.6117.4113.3114117.8118.953.4850%116.8120.7120.3117.5113.7117.7115.6114.8116.9116.755.0740%119.9117.2116.6116.2116.9118.5115.2115.4117.2117.554.7330%119.1119.2120.3119.9118.7116.6118.8118.3117.4118.254.7720%121.1119.8119.3119.9120.6120.4119.4119.9119.4119.855.2910%121.4121.2121.4120.9120.6120.1119.8120.5119.4120.156.20%121.4121.9121.9121.6121.8121.7121.7121.712212256.57

Graph of Shear Force v/s Rigidity

Table 3 Design of Beam 57 w.r.t rigidities

RigidGF1F2F3F4F5F6F7F8F9F10F100%ISLB400ISLB400ISLB400ISLB400ISLB400ISLB400ISLB400ISLB400ISLB400ISLB400ISLB32590%ISLB400ISLB400ISLB400ISLB400ISLB400ISLB400ISLB400ISLB400ISLB400ISLB400ISLB32580%ISLB400ISLB400ISLB400ISLB400ISLB400ISLB400ISLB400ISLB400ISLB350ISLB350ISLB32570%ISLB400ISLB400ISLB400ISLB400ISLB400ISLB350ISLB350ISLB350ISLB350ISLB350ISLB32560%ISLB400ISLB350ISLB350ISLB350ISLB350ISLB350ISLB350ISLB350ISLB350ISLB350ISLB32550%ISLB350ISLB350ISLB350ISLB350ISLB350ISLB400ISLB400ISLB400ISLB400ISLB400ISLB32540%ISLB400ISLB400ISLB400ISLB400ISLB400ISLB400ISLB400ISLB400ISLB400ISLB400ISLB32530%ISMB400ISMB400ISMB400ISMB400ISMB400ISMB400ISMB400ISMB400ISMB400ISMB400ISMB30020%ISMB400ISMB400ISMB400ISMB400ISMB400ISMB400ISMB400ISMB400ISMB400ISMB450ISMB30010%ISMB450ISMB450ISMB450ISMB450ISMB450ISMB450ISMB450ISMB450ISMB450ISMB450ISMB3500%ISMB500ISMB500ISMB500ISMB500ISMB500ISMB500ISMB500ISMB500ISMB500ISMB500ISMB350

Table .4 Theoretical Steel Quantity (kgs) for the Beam 57 per meter run

RigidGF1F2F3F4F5F6F7F8F9F10F100%106.2107.2106.2106.3106.2106.2105.9106.5105.8105.595.6690%106.7106.9106.3105.6105.2105.8105.9105.1104.3104.695.7380%105.7105.2105.9105.9104.7105.5104.8104.7104.1103.895.5970%105.8105.8104.5104.1104.3104.6104.5103.4103.8103.495.2760%104.9104.2104.8103.8103.9103.1103.9103.3103.6103.994.9750%104.2104.3104.9104.7103.7104.7104.8104.4104.5106.795.6240%106.1106.8106.1106.5105.8106.6106.1106.5106.4106.696.430%107.4107.5107.5108107.8107.6107.2107.7108.6108.697.6520%110.5110.4110.2110.5110.9110.4110.9110.6110.3111.199.3210%113.5113.1113.3113.8113.1113.3114.6114.6114.9114.1101.10%118.1118.3118.2118.5118.4118.2118.5118.6118.6118.8103.9

Graph of Theoretical Steel v/s Rigidity For Beam

Table 5 Practical Steel Quantity (kgs) for the Beam 57

RigidGF1F2F3F4F5F6F7F8F9F10F100%142.5142.5142.5142.5142.5142.5142.5142.5142.5142.5107.590%142.5142.5142.5142.5142.5142.5142.5142.5142.5142.5107.580%142.5142.5142.5142.5142.5142.5142.5142.5123.5123.5107.570%142.5142.5142.5142.5142.5123.5123.5123.5123.5123.5107.560%142.5123.5123.5123.5123.5123.5123.5123.5123.5123.5107.550%123.5123.5123.5123.5123.5142.5142.5142.5142.5142.5107.540%142.5142.5142.5142.5142.5142.5142.5142.5142.5142.5107.530%154154154154154154154154154154110.520%154154154154154154154154154181110.510%1811811811811811811811811811811310%217.5217.5217.5217.5217.5217.5217.5217.5217.5217.5131

Graph of Practical Steel v/s Rigidity For Beam

Table 6 Axial Load(KN) in Column 17 w.r.t rigidities

RigidGF1F2F3F4F5F6F7F8F9F10F100%3202.822865.062549.082243.471946.11665.951362.41065.7768.796462.055148.03190%3222.612882.542563.362251.841944.951673.381371.81071772.082462.944148.49880%3263.632927.832598.272282.531979.21678.11377.91074.7770.805460.62147.59270%3338.533000.112669.252345.732043.681746.341422.91104.1789.217474.068147.74960%3375.023032.122693.452367.832060.981762.361436.21118.5803.109478.736150.32950%3438.173099.0727652435.622113.951795.3714671144.3817.56486.597155.01940%3478.153133.642794.422466.282141.911819.411482.91152.1821.674489.129153.66430%3565.893217.542874.882530.952193.861854.121513.51171.2831.52493.291154.52320%3613.663262.652915.522569.082223.631879.061531.51186.6843.357499.75157.29110%3656.223303.12950.752599.072248.771900.691550.51202.1853.393507.153159.6550%3708.983353.972998.92643.9222891933.8515781222.8867.44513.424161.523

Graph of Axial load v/s Rigidity For Column

Table 7 Design of Column 17 w.r.t rigidities

RigidGF1F2F3F4F5F6F7F8F9F10F100%ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISWB550ISHB450ISHB350ISHB225ISHB15090%ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISHB450ISHB350ISHB225ISHB15080%ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISHB450ISHB350ISHB225ISHB15070%ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISHB450ISHB300ISHB225ISHB15060%ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISHB450ISHB300ISHB225ISHB15050%ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISHB450ISHB300ISHB200ISWB17540%ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISHB450ISHB300ISWB300ISWB15030%ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISHB450ISHB300ISWB250ISWB17520%ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISHB450ISHB350ISWB300ISWB17510%ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISHB450ISHB300ISHB200ISWB1750%ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISWB600ISHB450ISHB350ISHB225ISHB150

Table 8 Theoretical Steel Quantity (kgs) for the Column 17 w.r.t rigidities

RigidGF1F2F3F4F5F6F7F8F9F10F100%717.4651.2553.8540.7499.8425.4336.9250.6185.2118.665.890%735.5662.7591.8543.7503.8446.9349.2255.5190.8117.771.880%740.4682.9611.9541.8482.8420.2354.5255.5181.8121.777.970%759.4703.6631.4561.4511.5438.6632.4257.6177.5107.852.860%765.9712.9643.3577.8511.8433.9363.9248.9177.9111.842.950%784.3735.5670.6597.9508.7434.4359.5245.8172.5104.739.840%800.7730.1657.6586.5517.8448.1369.3254.7176.4123.944.630%815.6748.9676.7606.6523.9523.9446.9249.9174.8113.538.720%823.1754.9684.9611.7532.9452.6372.8270.9189.6122.838.910%832.2758.8680.9606.6525.6450.9376.4254.7182.9107.839.60%843.4764.2684.9603.3520.7439.8366.3254.8188.4116.947.8

Graph of Theoretical Steel v/s Rigidity For Column

Table 9 Practical Steel Quantity (kgs) for the Column 17 per meter run

RigidGF1F2F3F4F5F6F7F8F9F10F100%730.6577.8575.4553.8553.8435.9338277.9202.7140.881.490%730.6671.7612.7553.8530.2530.2401.7277.9202.7140.881.480%730.6695.8624.5553.8519.6435.9401.7277.9202.7140.881.470%766.2730.6648.2577.8530.2435.9401.7262.7189.3129.581.460%789.6730.6648.2612.7553.8435.9401.7262.7189.3129.981.450%789.6742.4695.8624.5530.2435.9401.7262.7176.9112.966.840%813.8742.4671.7612.7530.2506.6401.7262.7189.3144.651.930%848.5766.2695.8612.7530.2530.2506.6262.7176.9122.766.820%836.7766.2695.8624.5553.8577.8401.7277.9202.7144.666.810%836.7766.2695.8624.5530.2472.9401.7262.7189.3112.966.80%860.4789.6695.8624.5530.2472.9401.7262.4202.7129.981.4

Graph of Practical Steel v/s Rigidity For Column

SIMPLE CONNECTION

FloorSteelGF9.541F9.542F9.543F9.544F9.545F9.546F9.547F9.548F9.549F9.5410F4.536

Steel Quantity v/s Floors for simple connection

RIGID CONNECTION

FLOORSTEELGF9.421F7.442F8.753F8.14F8.425F7.446F8.437F8.438F9.219F8.6410F4.25

Steel Quantity v/s Floor for rigid connection

SEMI-RIGID CONNECTION

Semi-rigid conection

80%60%40%20%GF75.775.775.776.451F75.775.6375.5276.32F75.774.6575.2275.853F75.774.5374.8675.374F75.774.3374.7775.255F75.774.0974.5675.046F74.5974.0374.4775.047F74.2373.8974.2975.048F74.3373.8374.5674.479F66.83566.45560.7162.4410F44.4944.429.51536.855

Steel Qty v/s Floors for Semi-rigid connection

ConclusionsThe minimum bending moment is obtained when the rigidity is 50% to 60%.There is no much change in the shear force w. r. t. rigidities.The lighter beams have been got for 50% to 60% rigidity. Heavy beams have been found for 0% to 10% rigidity. Whereas for 60% to 100% the beam sections are almost sameFor simple connections there is no much variation in steel quantity and it decreases form GF to 10th floor because of less loads.For rigid connection there is regular increase and decrease in steel quantity and finally decreases till 10th floor.For semi-rigid connection steel quantity remains same upto 9th floor but reduces to 10th floor. The design is economical when the rigidity is between 50% to 60%.

ReferencesAng,K. M., and Morris, G. A. (1984). Analysis of Three-Dimensional Frames with Flexible Beam-Column Connections. Canadian Journal of Civil Engineering, Vol. 11, 245-254.

J.C.D.Hoenderkamp and H.H.Snijder (2000). Approximate analysis of high rise frames with flexible connections. The Structural Design of Tall Buildings, Vol. 9 , 233-248

Frye, M. J., and Morris, G. A. (1975). Analysis of Flexibly Connected Steel Frames. Canadian Journal of Civil Engineering, 2, 280-291.

ReferencesAli Ugur and Mutlu Secer (2005). An investigation for semi-rigid frames by different connection models. Mathematical and Computational Applications, Vol. 10, No. 1, pp. 35-44. Association for Scientific Research.

Goverdhan, A. V. (1983). A Collection of Experimental Moment-Rotation Curves and Evaluation of Prediction Equations for Semi-Rigid Connections. MS thesis, Vanderbilt University, Nashville, Tennessee.

ReferencesM.Sekulovic and M.Nefovska (2004). Static inelastic analysis of steel frames with flexible connections. Theoret. Appl. Mech., Vol.31, No.2, pp.101-134, Belgrade.

Jones, S. W., Kirby, P. A., and Nethercot, D. A. (1980). Effect of Semi-Rigid Connections on Steel Column Strength. Journal of Constructional Steel Research, 1(1), 38-46.

J. C. D. Hoenderkamp and M. C. M. Bakker, (2003). Analysis of high-rise braced frames with outriggers. The Structural design of tall and special buildings, 12, 335350.

ReferencesJones, S. W., Kirby, P. A., and Nethercot, D. A. (1983). The Analysis of Frames with Semi-Rigid Connections - A State-of-the-Art Report . Journal of Constructional Steel Research , 3(2), 2-13.

Bulent Akbas and Jay Shen (2003). Seismic behaviour of steel buildings with combined rigid and semi-rigid frames. Turkish J. Eng. Env. Sci 27, 253-264.

Kishi, N., and Chen, W. F. (1990). Moment-Rotation Relation of Semi-Rigid connection. Journal of Structural Engineering. 116(7), 1813-1834.

THANK YOU