Failure analysis of one-story precast structures for near-fault and far-fault strong ground motions

Abstract

Failure of one-story precast structures consisting of cantilever columns connected by simply supported beams was widely reported throughout the epicentral regions of the last devastating earthquakes in Turkey. As a single degree of freedom system, precast columns are designed by using the elastic spectrum given in the seismic code and by considering a seismic load reduction factor which takes into account the inelastic behavior of the columns under seismic loads. Although the existing seismic codes consider near-fault shaking effects in the development of elastic response spectra, they do not currently consider the increased inelastic demands that may occur during near-fault ground motion. The current study consists of nonlinear time history analyses of various hypothetical columns having geometric and mass properties which are being used in Turkish precast industry and the evaluation of damage indexes (DI) in terms of peak ground velocity (PGV) and peak ground acceleration (PGA) of the used strong ground motions. It is achieved that near-fault earthquakes create more damages on the columns. This might be one of the main reasons for the collapse of several one-storey precast buildings which were well designed according to the seismic codes in the district of existing faults. The obtained PGV versus DI charts prove that if one increase the sectional dimensions and/or longitudinal reinforcement ratio of the column, the possible damage from near-fault shaking effects could be reduced. 123 938 Bull Earthquake Eng (2010) 8:937-953 Fig.

Damage index for reinforced concrete columns

“…Some other modified versions of Park and Ang's [16] model, quite similar to the original model, have also been proposed. It is worth noting that Park and Ang model is still widely used by researchers although it was proposed in 1985 [19][20][21][22][23][24].…”

“…In this section, the damage index (DI) is calculated using the proposal formulation given in Eq. (24). For this purpose, eleven (11) specimens subjected to cyclic loading were carefully selected from the database compiled by M.O.…”

Bayesian updating of the Park-Ang damage index for RC frame buildings under near-fault ground motions

“…Park and Ang [3] took into account both hysteretic energy and deformation to present a damage model. Some researchers have attempted to improve this model [16][17][18], but the original ParkAng model is still widely used in structural damage analysis [19][20][21]. In order to numerically calculate damage indices, the correlation between performance levels and values of damage index has been studied [22].…”

Seismic damage assessment and FRP retrofit of reinforced concrete structures

“…Yüksel and Sürmeli [79] used the Park and Ang [4] model to evaluate the damage levels of columns with different cross-sectional dimensions and longitudinal reinforcement ratio subjected to near-fault and far-fault earthquakes. They found that, for a certain reinforcement ratio, the damage decreases as the dimensions of cross section increases.…”

“…The results of their investigation of the relationship between the probability of damage and the reinforcement ratio is shown in Table 2-2. Table 2-2 Damage probability of column Yüksel and Sürmeli [79].…”