Seismic Response Mitigation in G+4 Reinforced Concrete Buildings through Viscoelastic Damping Systems

Abstract

Earthquake-induced ground motions impose significant lateral forces on structures, leading to potential damage at critical sections such as beam-column connections. Conventional structural systems often rely on increasing member stiffness or cross-sectional area to cope with seismic demands, an approach that can be both materially intensive and economically burdensome. Supplemental energy dissipation devices, particularly passive dampers, have emerged as a structurally efficient alternative that redirects input energy away from the primary load-bearing elements. This study presents a comparative numerical investigation of seismic response parameters for a five-storey (G+4) reinforced concrete (RC) framed building, modelled both with and without viscoelastic (VE) dampers. The structure is designed in accordance with the Indian seismic design standard IS 1893:2002, located in Seismic Zone II with medium soil conditions. Finite element modelling and nonlinear time history analysis were carried out using the commercially available structural analysis software SAP2000. The 1994 Northridge earthquake ground motion record (Mw 6.7) was employed as the seismic input to capture realistic dynamic demands. Critical beam sections exhibiting the highest bending moment demand were identified and selected as optimal locations for damper placement. Viscoelastic dampers were incorporated at all four exterior sides of the frame, extending throughout the building height. Key response metrics evaluated include peak top-floor displacement, inter-storey drift at each floor level, and base shear. Results demonstrate that the incorporation of VE dampers reduces peak top displacement by approximately 17.08% while significantly increasing effective base shear resistance by about 65.21%, confirming the dual benefit of energy absorption and enhanced lateral stiffness. The findings validate the practicality and effectiveness of VE dampers as a retrofit and new-construction strategy for earthquake-resistant RC buildings.

Introduction

This study investigates the effectiveness of viscoelastic (VE) dampers in reducing the seismic response of reinforced concrete (RC) buildings. Earthquakes pose a major threat to structures, especially in India, where about 54% of the land area falls within moderate to high seismic zones. Traditional seismic design relies on ductility and controlled damage through plastic hinging, which prevents collapse but often results in expensive repairs after earthquakes. VE dampers offer an alternative by absorbing and dissipating seismic energy, thereby protecting the structural frame.

Objectives

The study aims to:

• Develop a SAP2000 model of a G+4 RC building according to IS 1893:2002.
• Identify critical structural sections using bending moment and shear force analysis.
• Install and optimize VE dampers at critical locations.
• Perform nonlinear time-history analysis using the 1994 Northridge earthquake record.
• Compare the seismic performance of bare and damped structures in terms of displacement, inter-storey drift, and base shear.

Literature Review

Previous research has shown that passive damping systems significantly improve seismic performance:

• VE dampers reduce displacement and acceleration demands in RC buildings.
• Studies reported displacement reductions of up to 50% and inter-storey drift reductions of up to 78%.
• Fluid viscous and friction dampers also improve structural behavior and reduce vibration effects.
  These findings support the use of VE dampers for seismic mitigation.

Structural Modeling

A G+4 moment-resisting RC frame was modeled with:

• Plan dimensions: 35 m × 35 m
• Five storeys (17.5 m total height)
• Seven bays in each direction with 5 m spacing
• Column size: 0.4 m × 0.4 m
• Beam size: 0.3 m × 0.3 m
• Slab thickness: 120 mm
• Located in Seismic Zone II on medium soil

The model was developed in SAP2000 using frame elements for beams and columns and shell elements for slabs.

Material Properties

The building uses:

• M25 concrete
• Fe415 reinforcing steel
• Damping ratio of 5%
• Standard elastic and strength properties defined in SAP2000.

Viscoelastic Dampers

VE dampers consist of polymer layers sandwiched between steel plates. During an earthquake, the polymer deforms in shear and converts mechanical energy into heat.

Advantages

• Reduces seismic and wind-induced vibrations.
• Prevents excessive damage and plastic hinging.
• Lowers repair and maintenance costs after earthquakes.
• Suitable for both new buildings and retrofitting existing structures.
• Adds minimal mass to the structure.

Critical Section Identification

A static analysis under gravity loading was performed to locate the most highly stressed structural members. The exterior beam at the base storey was identified as the critical section due to its maximum bending moment demand. This location was selected for evaluating and optimizing VE damper placement.

Conclusion

1) The overall seismic performance of the G+4 RC frame improves substantially with peripheral VE dampers spanning the full building height. 2) Peak top-floor displacement is reduced by 17.08 % (from 0.1206 m to 0.10 m) under the 1994 Northridge ground motion, confirming effective energy absorption by the dampers. 3) Inter-storey drift decreases at every storey level, with the largest absolute reductions at the upper floors, reducing the risk of both structural and non-structural damage. 4) Base shear increases by 65.21%, reflecting the stiffness contribution of the VE dampers and indicating a stiffer, more controlled lateral load-resisting mechanism. 5) Critical sections at base-level exterior beams—identified from bending moment envelopes—are confirmed as optimal damper locations; peripheral placement across all storey’s is effective. 6) VE dampers are suitable for both new construction and seismic retrofit of RC buildings in India, particularly in low-to-medium seismic zones. 7) Future work should investigate Zone III–V buildings, taller structures (G+10 and above),multiple ground motion records, and parametric variations in damper mechanical properties.

References

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Copyright

Copyright © 2026 Amy Thomas, Aryan Kumar Singh, Ashutosh Kumar Singh, Devansh Misra, Raghav Gangrade, Rohit Sahu. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.