On the capacity of high, moderate and low earthquake frequency content to cause global drift ratio at level-2 of structural performance

Abstract

The earthquake (EQ) frequency content can be high, moderate or low frequency, mainly depends on epicenter’s distance and local soil conditions. The EQ frequency content will affect on the inelastic response of building structures. According to Vision 2000 and FEMA 356 under particular hazard level, the building is expected to perform structural response either fully operational, immediate occupancy, life safety or near collapse. Numerical investigation of 10-stories mid-rise reinforced concrete frame structure subjected to variations of the earthquake frequency contents has been conducted. The building model is assumed to be located at Yogyakarta on the soft soil condition. The building model it was shaken by various EQ frequency contents and maximum ground accelerations (PGA) until approaching the global drift ratio (GDR) of 0.50, 0.75, 1.00, 1.25, 1.50, 1.75 and 2.00 %. Result of investigation show that the EQ high frequency is almost impossible to cause GDR ± 2.0% since it needs PGA as high as 4.01g. Under the possible maximum recorded PGA in the field, the only EQ with low frequency content which has capacity to cause maximum GDR reaches ± 2.0%. or at maximum of structural performance level. Between GDR and overall damage index (ODI) is linearly correlated, however boundaries of the performance levels according to GDR and ODI does not meet at the same point.