Improvement of energy damage index bounds for circular reinforced concrete bridge piers under dynamic analysis

Abstract

An improvement of energy damage index bounds for circular reinforced concrete (RC) bridge piers under dynamic time history analysis is presented in this study. The energy-based damage model has been defined as a ratio of hysteresis dissipation energy to input energy for performance evaluation of circular RC bridge pier systems. Based on the energy balance equation, the mentioned damage model can consider all energy aspects, including kinematic energy, strain energy, hysteresis energy, damping energy, and input energy. Additionally, the effect of ground motion duration, amplitude, and frequency content is appropriately considered in this damage model. For this purpose, the damage limit state bounds for two empirical RC bridge piers are statistically evaluated under the 22 far-field ground motion sets of FEMA-P695 for simulation of strong-earthquake motion and consideration of record-to-record variability.First of all, appropriate validation between empirical and numerical fiber element models is implemented to estimate accurate results. Then, damage data at each performance level through strain limit states are collected by developing energy incremental dynamic analysis curves. Statistical results on collected damage data are presented in all performance levels to determine damage index bounds by the convolution of fragility curve distribution. Hence, five damage index bounds at five performance-level are suggested, including very slight, slight, moderate, extensive, and complete damage. Finally, the effect of the other damping ratios on the modified energy damage model is carried out by using the beta coefficient in the formula. In the end, the modified energy damage model is compared with other damage indices to investigate the efficiency of the proposed damage model.

The Modified Energy-based Method for Seismic Evaluation of Structural Systems with Different Hardening Ratios and Deterioration Hysteresis Models

“…Although structural systems under strong ground motion shaking illustrate uncontrollable and unpredictable structural damage [24], predicting target displacement for initial evaluation of component status in structural elements and predicting probable behavior of them in future earthquakes plays a significant role in performance-based plastic design and rehabilitation of buildings. The energy balance concept has been developed for predicting target displacement in structural systems based on the assumption that the energy computed from the monotonic load (capacity spectrum) is equal to input energy produced by earthquake ground motions.…”

Influence of Seismic Loads Considering Soil Properties and Wave Passage Effect on the Seismic Response of a Multi-Span PSC Girder Bridge

“…When evaluating the dynamic response of a bridge during an earthquake, the most important factor to be considered is the seismic load acting on the bridge. Prior studies were conducted experimentally or analytically by applying seismic waves obtained from earthquakes such as El Centro, Ofunato, and Hachinohe to structures [24][25][26][27]. However, each real seismic wave has its own characteristics, which may cause different results depending on the natural frequency of the structure [28].…”