Optimal intensity measures for probabilistic seismic demand modeling of multi-span continuous concrete box girder bridges subjected to near-field earthquakes

Subject Areas : Analysis of Structure and Earthquake

Hoodean  Malekzadeh ¹ (Department of Civil Engineering, Faculty of Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran)
Hassan  Abbasi ² (Civil Engineering Department, Faculty of Engineering Islamic Azad University, South Tehran Branch)
Mahmood  Hooseini ³ (Structural Institute, International Institute of Earthquake Engineering and Seismology, Tehran, Iran)
Armin  Aziminejad ⁴ (دانشگاه آزاد اسلامی واحد علوم و تحقیقات تهران، ایران)
Mohammadreza  Adib Ramezani ⁵ (Department of Civil Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran)

Received: 2021-06-19 Accepted : 2021-08-14 Published : 2021-08-23

Keywords: Nonlinear Time History Analyses, Optimality investigation, Optimal intensity measures, Opensees framework, Near-field earthquakes, Probabilistic seismic demand model,

Abstract :

Seismic intensity measures (IMs) perform a pivotal role in probabilistic seismic demand modeling. Past studies investigated appropriate IMs for structures, including the vital component of the transportation system, the highway bridges. These studies were mainly focused on far-field earthquakes and did not consider the strong vertical component of ground motions in near-field earthquakes.  In order to evaluate the optimal IMs for the multi-span continuous concrete box girder bridges subjected to near-field earthquakes, ten sample bridges were modeled and then subjected to three-component records of 164  near-field earthquakes applying the OpenSees software framework. In the present research, 5 engineering demand parameters considering the most critical response parameters related to columns and deck were selected, along with 24  intensity measures considering the horizontal and vertical components of ground motions. Base on the optimality investigation method, parameters such as efficiency, practicality, proficiency, sufficiency, and relative sufficiency were considered. In total, 8200 nonlinear time-history analyses were conducted. The results presented that the peak ground velocity of the horizontal component (PGVH), velocity spectrum intensity of the horizontal components(VSIH), and Housner intensity of horizontal components (HIH) were the optimal intensity measures, and vertical component of ground motions in near-field earthquakes should be considered in optimality investigation.