Investigation of story ductility demands of inelastic concrete frames subjected to repeated earthquakes

The ductility-based strength reduction factor for the mainshock–aftershock sequence-type ground motions

“…ground motion parameters relationship between mainshock and aftershock) to quantitatively and clearly describe this interdependence. This randomly combining method has been applied in several researches (Hatzigeorgiou 2010a, b;Faisal et al 2013;Zhai et al 2013a;Ruiz-García et al 2014). Though the artificial sequence-type ground motions may not perfectly reflect this interdependence and errors may be induced by using these artificial sequence-type ground motions to compute the structural response, the results in these investigations still showed that the artificial sequence-type ground motions generated by this method have the acceptable potential to study the influence of multiple successive ground motions on the seismic response of structures.…”

“…Some researchers (Sunasaka et al 2002;Amadio et al 2003;Das et al 2007;Hatzigeorgiou and Beskos 2009;Hatzigeorgiou 2010a, b, c;Goda and Taylor 2012;Goda 2012;Di Sarno 2013;Zhai et al 2013aZhai et al , 2014 focused on the inelastic response spectra, such as inelastic displacement ratio, ductility demand, behavior factor and damage spectra for mainshock-aftershock sequence-type ground motions. In addition, several investigations (Fragiacomo et al 2004;Lee and Foutch 2004;Li and Ellingwood 2007;Hatzigeorgiou and Liolios 2010;Moustafa and Takewaki 2010;Ruiz-García and Negrete-Manriquez 2011;Ruiz-García 2012;Ruiz-García et al 2012Faisal et al 2013;Zhang et al 2013;Efraimiadou et al 2013;Han et al 2014) have been conducted to study the effects of aftershock on multiple-degree-of-freedom structures.…”

Sequential Ground Motion Effects on the Behavior of a Base-Isolated RCC Building

“…Though the average PGA AS /PGA MS is close to 1, the average maximum relative displacement for the fixed-base RCC rises by 21.4%, growing from 0.0210 m under mainshocks to 0.0255 m under seismic sequences, while no difference of the average maximum relative displacement for the base-isolated RCC can be found between mainshocks and multiple ground motions. It should be mentioned that Coalinga seismic sequence (number (12)) induces the largest displacement increase (0.015 m) for the fixed-base RCC in comparison with the corresponding mainshock while the increase is only 0.003 m for the base-isolated RCC. Obtained results indicate that isolators can not only reduce the structural deformation significantly but also prevent strong aftershocks from causing more permanent deformation to the structure.…”

“…After the Tohoku-Oki earthquake with magnitude Mw9.0 occurring on March 11, 2011, in Japan, a large number of aftershocks struck the same area and the greatest one reached magnitude Mw7.9. Due to the potentially devastating effect of aftershocks, a great number of researchers attempted to investigate the effects of aftershocks on different structural systems, including the single-degreeof-freedom systems [2][3][4][5][6][7][8][9][10], reinforced concrete structures [11][12][13][14][15][16][17][18], steel structures [19][20][21][22], and wood-frame buildings [23][24][25]. As the last defense against nuclear leakage, the reinforced concrete containment (RCC) building subject to sequential ground motions is researched by [26].…”

Seismic response of self-centering prestressed concrete moment resisting frames with web friction devices

“…For instance, during the 2008 Wenchuan, China earthquake sequence, dozens of damaged reinforced concrete (RC) buildings weakened by the main-shock suffered from partial or complete collapse due to aftershocks. Numerical studies on the responses of RC moment frames [15,16] have also indicated that aftershocks may increase the damage state of structures at the end of the main-shock. Despite the fact that repeated earthquakes hazard is clearly threatening, the effect of repeated earthquakes on post-tensioned structures has not gained much attention.…”