Comparative Seismic Analysis and Optimization of 6 RC Buildings Using SAP2000

Response Spectrum Analysis in SAP2000 | IS 1893 (Part 1): 2016

Project Summary

Comparative seismic analysis of 6 RC building models (G+5 to G+20, regular and vertically irregular) using the Response Spectrum Method as per IS 1893:2016 in SAP2000 v25.

Key Question: How do building height, vertical irregularity, and shear walls affect seismic response?

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Models Analyzed

Model	Configuration	Height
1	G+5 Regular Bare Frame	18 m
2	G+10 Regular Bare Frame	33 m
3	G+15 Regular Bare Frame	48 m
4	G+20 Regular Bare Frame	63 m
5	G+20 Vertically Irregular (Setback at 11F)	63 m
6	G+20 Irregular + Central RC Shear Wall Core	63 m

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Key Results

Parameter	G+5	G+20 Regular	G+20 Irregular	G+20 + Shear Wall
Time Period (s)	0.831	3.121	2.313	1.951
Base Shear (kN)	236.5	239.1	315.8	577.4
Max Drift (mm)	1.365	1.400	1.631	1.406

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Key Engineering Findings

1. Time period increases consistently with building height (0.831s → 3.121s)
2. Base shear is NOT linearly proportional to height — peaked at G+10 (282.4 kN)
3. Vertical irregularity increased base shear by 32% vs regular G+20
4. Central shear wall core reduced maximum drift by 13.8% (DREI = 13.8%)
5. Drift Concentration Factor (DCF) of optimized model = 2.15
6. Lower base shear does NOT imply safer structural performance

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Tools & Standards

• Software: SAP2000 v25
• Analysis Method: Response Spectrum Analysis (CQC combination)
• Codes: IS 1893:2016, IS 456:2000, IS 875 Part 2, IS 13920

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Seismic Parameters Used

• Zone III | Z = 0.16 | I = 1.0 | R = 5 (SMRF)
• Medium Soil (Type II) | Damping = 5%

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Files in This Repository

• /Report Seismic Analysis of Regular and Irregular RC Buildings by Aman Paturde.pdf

• /Model Screenshots

• /Results

• /Drift Profiles

• /Comparative Graphs