تاثیر حرکت قوی زمین و بارهای متحرک روی پاسخ یک پل بتنی اریب جداسازی شده

Huge damages occurred in Hanshin highway in 1995, has clearly shown destructive role of vertical component of strong ground motions. On the other hand, in current design codes, track loads are considered as equivalent static loads moves along the deck without considering their inertial effects. Therefore, in this paper a special evaluation is performed for a skew 3-span concrete bridge. First, seismic performance and vulnerability of the bridge are investigated. Effective loads are a 3-component strong ground motion and track moving loads, individually. Second, by use of isolation systems seismic performance of the bridge are improved such that forming and development of plastic hinges along the piers are prevented. Also, since because of different earthquake force transmission paths and position of isolation systems there are basic differences between designs of isolation system for building and bridges, special considerations has been carried out. All the analyses are the dynamic nonlinear time history including inelastic behavior of the bridge elements and base-isolation system. The Hanshin (kobe) acceleration record,17 Jan.1995 is selected for strong ground motion. Defined track load of AASHTO is used for moving load with various vehicle speeds. Results show that strong ground motion has an important role in design of isolation system and there are considerable differences between seismic isolation systems arrangement under seismic analysis and moving load analysis.

Keywords:

skew3-span concrete bridge , isolation system , 3-component strong ground motion , moving load