Seismic response of multi-span highway bridges with two-column reinforced concrete bents including foundation and column flexibility

Download
2008
Yılmaz, Taner
Seismic design of highway bridges has improved as a result of the experience gained from large earthquakes of the last thirty years. Ductility demand and reserved capacity are extremely important response measures used in new bridge designs to assess target damage levels. However, the application of practical design approaches specified in bridge design codes is not well-defined for bridges over flexible foundations. Within the scope of this research, thirty two bridge models having varying column aspect ratio, amount of column longitudinal reinforcement and foundation flexibility parameters are investigated through a series of analyses such as response spectrum analysis and inelastic time-history analysis under “safety evaluation earthquake” hazard level with a return period of 1000 years, and push-over analysis. Using the results of analyses, seismic response of the investigated bridges are identified with several measures such as displacement capacity over demand ratio, global displacement ductility demand, and response modification factor, along with maximum concrete and steel strains of columns. A correlation between concrete and steel strains and seismic response measure values is constructed to estimate damage levels with commonly used response measures. The findings of this research revealed that global displacement ductility demand is not a favorable response measure for assessing damage levels. On the other hand, displacement capacity over demand ratios can be suggested for estimation of damage levels especially where foundation flexibility effects are extensive as system yielding is not taken into consideration.

Suggestions

Energy based seismic performance assessment of reinforced concrete columns
Acun, Bora; Sucuoğlu, Haluk; Department of Civil Engineering (2010)
Severe seismic events in urban regions during the last two decades revealed that the structures constructed before the development of modern seismic codes are the most vulnerable to earthquakes. Sub-standard reinforced concrete buildings constitute an important part of this highly vulnerable urban building stock. There is urgent need for the development and improvement of methods for seismic performance assessment of existing reinforced concrete structures. As an alternative to current conventional force-ba...
Fragility based seismic vulnerability assessment of ordinary highway bridges in Turkey
Avşar, Özgür; Yakut, Ahmet; Department of Civil Engineering (2009)
Recent devastating earthquakes revealed that bridges are one of the most vulnerable components of the transportation systems. These seismic events have emphasized the need to mitigate the risk resulting from the failure of the bridges. Depending on the seismicity of the bridge local site, seismic vulnerability assessment of the bridges can be done based on the fragility curves. These curves are conditional probability functions which give the probability of a bridge attaining or exceeding a particular damag...
Seismic performance of multisimple-span bridges retrofitted with link slabs
Caner, Alp; Zia, P. (American Society of Civil Engineers (ASCE), 2002-03-01)
During earthquakes multisimple-span bridges are vulnerable to span separation at their expansion joints. A common way of preventing unseating of spans is to have cable or rod restrainers that provide connections between adjacent spans. Alternatively, dislocation of the girders can be controlled with a link slab that is the continuous portion of the bridge deck between simple spans. Seismic retrofit with link slab should be more cost-effective than the existing methods when it is performed during redecking o...
Seismic vulnerability, behavior and design of tunnel form building structures
Balkaya, C; Kalkan, E (Elsevier BV, 2004-12-01)
Multi-story reinforced concrete tunnel form buildings are one of the common structural types in regions prone to high seismic risk due to the buildings inherent earthquake resistance and ease of construction. Despite their good performance during earthquakes in 1999 in Turkey, and abundance of such structures scattered worldwide, current seismic codes and design provisions provide insufficient guidelines for their seismic design. As a compensatory measure, a series of modal and nonlinear static analyses are...
Dynamic effects of moving traffic on railway bridges
Cinek, Fatih; Yılmaz, Çetin; Department of Civil Engineering (2010)
In this study, dynamic effects on high speed railway bridges under moving traffic are investigated. Within this context, the clear definition of the possible dynamic effects is provided and the related studies that exist in literature are investigated. In the light of those studies, analytical procedures that are defined to find the critical dynamic responses such as deflections, accelerations and resonance conditions are examined and a MatLab programming language is written to obtain the responses for diff...
Citation Formats
T. Yılmaz, “Seismic response of multi-span highway bridges with two-column reinforced concrete bents including foundation and column flexibility,” M.S. - Master of Science, Middle East Technical University, 2008.