A comparative study of static and response spectrum analysis of a rc building
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This presentation compares the results of static and response spectrum analysis of a 6-story reinforced concrete building. A 3D model of the building was created in ETABS and both static and dynamic analysis were performed. The natural periods and mode shapes were determined from the dynamic analysis. Storey displacements, drifts, and member forces from both analyses were compared. The dynamic analysis produced significantly higher results than the static analysis for storey displacements, drifts, shear forces, and bending moments. Specifically, dynamic displacements were over 2.5 times higher and bending moments were around 2 times higher than the static analysis results.
A comparative study of static and response spectrum analysis of a rc building
- 1. PRESENTATION ON A Comparative Study of Static and Response Spectrum Analysis of a RC Building
- 2. TAMEEM SAMDANEE 10.01.03.127 JOHINUL ALAM 10.01.03.036 MD. ZAHIDUL ISLAM 10.01.03.142 ABU SYED MD. TARIN 10.01.03.020 UNDER THE SUPERVISION OF ZASIAH TAFHEEM ASSISTANT PROFESSOR DEPARTMENT OF CIVIL ENGINEERING, AUST
- 3. To determine the natural period of vibrations for different mode shapes of the comprehensive 3D using modal analysis techniques. To determine the storey-displacements and storey-drifts for each storey of a six storied building. To determine the base shears of the building under seismic loading. To determine the column shear forces and bending moments following the Equivalent Static Force Method (BNBC’93) and Response Spectrum Analysis (Dynamic) using a comprehensive 3D finite element software package ETABS v13.0 To make a comparative study of the results obtained from the static and dynamic analysis.
- 4. In this study, a 3D symmetric model of a six- storied building has been created using ETABS V-13.0 The structure has a constant stiffness and a linear behavior of all material properties. Equivalent Static Force Method (BNBC’93) has been used for static analysis. Response Spectrum Method has been used for dynamic analysis.
- 5. Earthquake is a series of vibrations induced in the earth’s crust by the abrupt rupture and rebound of rocks in which elastic strain has been slowly accumulating. The release of the energy results in vibratory waves propagating through the surface in all directions.
- 6. Factors affecting the earthquake performance of reinforced concrete structure: Ductility Capacity Effects of Drifts P-Delta effect Effects of strong Beams and weak Columns
- 7. Static Analysis Response Spectrum Analysis Time History Method
- 8. It assumes that the building responds in its fundamental mode. The building must be low-rise and must not twist significantly when the ground moves. Generally determines the shear acting due to an earthquake as equivalent static base shear.
- 9. The basic mode superposition method. Restricted to linearly elastic analysis. Produces the complete time history response of joint displacements and member forces. Involves the calculation of only the maximum values of the displacements and member forces.
- 10. It is an analysis of the dynamic response of the structure at each increment of time, when its base is subjected to a specific ground motion time history.
- 11. Material Properties Material Name Parameter Values Unit Concrete Mass per unit volume 4.662 lb-s2/ft4 Weight per unit volume 150 lb/ft3 Modulus of Elasticity 3604996.5 psi Poisson’s ratio 0.2 Concrete compressive strength, 3500 psi Steel Steel yield strength, 60000 psi
- 12. Section ID Section Size (in×in) Corner Column 12×12 Ext. Column 14×14 Int. Column 17×17 Beam 16×12 Grade Beam, GB 16×12 Section Properties Slab Properties Section name Thickness Type Slab Membrane: 5" Bending: 5" Shell
- 13. 3D View of the building
- 14. Beam Layout
- 15. Column Layout
- 16. Deformed Shape (Static) Due to EQX Load
- 17. Deformed Shape (Dynamic) Due to Response Spectrum
- 18. Mode Name Time Period Frequencies Mode 1 2.436 0.41 Mode 2 2.34 0.42 Mode 3 2.29 0.43 Mode 4 0.704 1.42 Mode 5 0.679 1.47 Mode 6 0.657 1.52 Mode 7 0.374 2.67 Mode 8 0.359 2.78 Mode 9 0.351 2.84 Mode 10 0.245 4.08 Mode 11 0.233 4.29 Mode 12 0.231 4.32 Mode Shapes
- 19. Mode Shapes Mode- 1 Mode- 2
- 20. Mode Shapes Mode- 3 Mode- 4
- 21. Mode Shapes Mode- 5 Mode- 6
- 22. Mode Shapes Mode- 7 Mode- 8
- 23. Mode Shapes Mode- 9 Mode- 10
- 24. Mode Shapes Mode- 11 Mode- 12
- 27. Comparative Study Maximum Storey Displacement
- 29. Comparative Study Shear Forces (Corner Columns)
- 30. Comparative Study Shear Forces (Exterior Columns)
- 31. Comparative Study Shear Forces (Interior Columns)
- 32. Comparative Study Maximum Shear Forces
- 33. Comparative Study Total Shear Forces
- 34. Comparative Study Bending Moments (Corner Columns)
- 35. Comparative Study Bending Moments (Exterior Columns)
- 36. Comparative Study Bending Moments (Interior Columns)
- 37. Comparative Study Maximum Column Bending Moments
- 38. • In the study of Maximum displacement of storey comparison between static and dynamic, we find dynamic is 276 percent of static analysis. • In the study of Storey drift comparison between static and dynamic, we find dynamic is 301 percent of static analysis. • In the study of Maximum Bending moment of column, the percentage of dynamic is 204% for corner, 239% for exterior, 210% for interior of Static analysis. • In the study of Maximum shear forces of columns, dynamic is almost 286 percent of static analysis for all columns.
- 39. Dynamic analysis may be done by other methods. Structures of nonlinear materials may be introduced for further analysis and design. Irregular shaped structure may be introduced for further analysis and design. Dynamic analysis may be introduced for further analysis and design. Commercial buildings may be introduced for further analysis and design.
- 40. THANK YOU