Evaluasi Pengaruh Kerusakan Akumulatif Akibat Gempa Berulang Terhadap Penurunan Kinerja Struktur Beton Bertulang

Abstract

This study aims to evaluate and model the performance degradation of reinforced concrete (RC) building structures subjected to mainshock-aftershock sequences. Building structures located in active seismic regions frequently face the threat of aftershocks before fully recovering from mainshock damages, triggering material fatigue escalation and plastic hysteretic energy accumulation. Employing a numerical computational approach via Nonlinear Time History Analysis (NLTHA) utilizing fiber element modeling, sequential simulations were conducted to track the evolution of structural damage. Quantitative evaluation using the Park-Ang Damage Index reveals that aftershock exposure with high magnitudes and short time delays triggers severe inter-story drift surges and lateral stiffness degradation, driving structures into critical collapse zones. These findings emphasize the critical importance of incorporating cumulative damage factors into future seismic design standards and structural vulnerability assessments.