Analytical investigation of aashto lrfd response modification factors and seismic performance levels of circular bridge columns

Download
2010
Erdem, Arda
Current seismic design approach of bridge structures can be categorized into two distinctive methods: (i) force based and (ii) performance based. AASHTO LRFD seismic design specification is a typical example of force based design approach especially used in Turkey. Three different importance categories are presented as “Critical Bridges”, “Essential Bridges” and “Other Bridges” in AASHTO LRFD. These classifications are mainly based on the serviceability requirement of bridges after a design earthquake. The bridge’s overall performance during a given seismic event cannot be clearly described. Serviceability requirements specified for a given importance category are assumed to be assured by using different response modification factors. Although response modification factor is directly related with strength provided to resisting column, it might be correlated with selected performance levels including different engineering response measures. Within the scope of this study, 27216 single circular bridge column bent models designed according to AASHTO LRFD and having varying column aspect ratio, column diameter, axial load ratio, response modification factor and elastic design spectrum data are investigated through a series of analyses such as response spectrum analysis and push-over analysis. Three performance levels such as “Fully Functional”, “Operational” and “Delayed Operational” are defined in which their criteria are selected in terms of column drift measure corresponding to several damage states obtained from column tests. Using the results of analyses, performance categorization of single bridge column bents is conducted. Seismic responses of investigated cases are identified with several measures such as capacity over inelastic demand displacement and response modification factor.

Suggestions

Effective flexural rigidities for ordinary reinforced concrete columns and beams
AVŞAR, ÖZGÜR; BAYHAN, BEYHAN; Yakut, Ahmet (Wiley, 2014-04-25)
Current effective flexural rigidities proposed for use in design and analyses of reinforced concrete structures have been examined. The level of accuracy in the estimation of section rigidity plays a very important role in determining realistic values for the structural stiffness and hence the seismic forces imposed. The most significant parameters influencing the effective rigidity, which reflects the effect of cracking as well as the theoretical yielding of reinforced concrete sections, have been determin...
Seismic design of lifeline bridge using hybrid seismic isolation
Dicleli, Murat (American Society of Civil Engineers (ASCE), 2002-03-01)
This paper presents the merits of a hybrid seismic isolation system used for the seismic design of a major bridge. The bridge is analyzed for two different arrangements of seismic isolation systems. The first arrangement consists of friction pendulum bearings at all substructure locations; the other incorporates a hybrid system where laminated elastomeric bearings are used at the abutments and friction pendulum bearings at the piers. Analysis results have demonstrated that the hybrid seismic isolation syste...
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...
Analytical formulation of maximum length limits of integral bridges on cohesive soils
Dicleli, Murat (Canadian Science Publishing, 2005-08-01)
This paper presents an analytical approach for predicting the length limits of integral bridges built on cohesive soils based on the flexural strength of the abutments and the low cycle fatigue performance of the steel H-piles at the abutments under cyclic thermal loading. First, H-piles that can accommodate large inelastic deformations are determined considering their local buckling instability. Then, a damage model is used to determine the maximum cyclic deformations that such piles can sustain. Next, non...
Seismic retrofitting of bridges by response modification techniques based on altering bearing fixities
Dicleli, Murat (Informa UK Limited, 2005-07-01)
Feasibility of a proposed seismic retrofitting technique for typical bridges in the Central US has been studied. The retrofitting technique is based on modifying the fixity conditions of the bearings for response modification purposes to eliminate the need for costly retrofitting of substructures. For this purpose, a seismically vulnerable bridge, typical of those in the Central US was selected. Detailed seismic analyses of the bridge were then conducted. It was found that its bearings, wing-walls and pier ...
Citation Formats
A. Erdem, “Analytical investigation of aashto lrfd response modification factors and seismic performance levels of circular bridge columns,” M.S. - Master of Science, Middle East Technical University, 2010.