Estimation of the Seismic Damage Potential of RC Frames Using Seismic Parameters

Variation of the fundamental period is regarded as one of the methods to assess the damage of the structures under earthquakes. The inter-relationship among seismic parameters and variation of the fundamental period can identify the potential structural damage of an earthquake. For this purpose, the present paper aimed to study the relations among main seismic parameters, incorporating a variety of information about ground motion and variation of fundamental period. Three RC frames were analyzed under far-fault earthquake records by nonlinear dynamic analyses and mathematical methods applied to assay the correlation between seismic parameters and variation of fundamental period. Based on the results, high correlations were observed between some seismic parameters and variation of fundamental period. Further, based on regression equations, new parameters with a very strong correlation with variations of fundamental periods were achieved, which can be regarded as appropriate indices to estimate the potential structural damage of an earthquake.

Influence of near-fault characteristics on inelastic response of multi-storey building with intensity measurement analysis

This study is presented to achieve three objectives: (1) to compare between the inelastic responses of buildings under near and far fault excitations, (2) to investigate the effect of the pulse to structural period ratio, and (3) to evaluate a set of intensity measurements (IMs) in terms of near fault (NF) earthquakes. A real reinforced concrete building with 35 storeys is analysed in the scope of the first and second objectives, whereas the third objective involves three general-frame buildings consisting of 6, 13, and 20 storeys. Results show that the NF excitation can drive the building to exceed its life safety performance level. Furthermore, the accuracy of the IM highly depends on the vibration period of the building and the function used to calculate the IM.

Efficiency of Intensity Measures Considering Near- and Far-Fault Ground Motion Records

This paper focuses on the identification of high-efficiency intensity measures to predict the seismic response of buildings affected by near- and far-fault ground motion records. Near-fault ground motion has received special attention, as it tends to increase the expected damage to civil structures compared to that from ruptures originating further afield. In order to verify this tendency, the nonlinear dynamic response of 3D multi-degree-of-freedom models is estimated by using a subset of records whose distance to the epicenter is lower than 10 Km. In addition, to quantify how much the expected demand may increase because of the proximity to the fault, another subset of records, whose distance to the epicenter is in the range between 10 and 30 Km, has been analyzed. Then, spectral and energy-based intensity measures as well as those obtained from specific computations of the ground motion record are calculated and correlated to several engineering demand parameters. From these analyses, fragility curves are derived and compared for both subsets of records. It has been observed that the subset of records nearer to the fault tends to produce fragility functions with higher probabilities of exceedance than the ones derived for far-fault records. Results also show that the efficiency of the intensity measures is similar for both subsets of records, but it varies depending on the engineering demand parameter to be predicted.