Live load reliability index evaluation for post tensioned balanced cantilever bridges

Çakır, Berk Bora
The purpose of this study is to determine the level of safety of the segmental post tensioned bridges designed according to AASHTO LRFD. Main span lengths are 90, 120, 150, 180 are studied in this paper. Four types of trucks are used; H30-S24T and L (currently be in use to design bridges in Turkey), HL-93(AASHTO), KGM-45 (is a new type of load consisting both axle load and lane load). Statistical parameters of truck loads are determined according to the data gathered from the Division of Transportation and Cost Studies of the General Directorate of Highways of Turkey. Target reliability index for ultimate state is chosen as 4.5 at first, then Service 3 stresses with corresponding reliability indices for ultimate capacities are computed. Moreover, this study shows if it is suitable to use the AASHTO LRFD tension limit stress for Service 3 Load Combination. Computing the uncertainties of live load models, extrapolation factors are calculated for 75 years and results are compared whether the corresponding live load models are adequate for the service life of infrastructures. The most critical reaction is considered in reliability index calculations, the negative moment of pier zone. In addition, reliability indices are calculated for different level of stresses for Service 3 and optimum tensile limit stress is rearranged for Turkish Design Code.


Reliability based evaluation of seismic design of Turkish bridges by using load and resistance factor method
Yılmaz, Seyit Alp; Caner, Alp; Department of Civil Engineering (2014)
This study aims to evaluate the safety level of seismic design of Turkish highway bridge pier columns with respect to reliability theory. Evaluation of bridges was performed for four different codes of American Association of State Highway and Transportation Officials (AASHTO). Reliability indices were calculated for AASHTO Load and Resistance Factor Design 2010 (AASHTO LRFD 2010), AASHTO LRFD 2007, AASHTO Standard Specifications of Highway Bridges (LFD 2002) and Turkish modification of AASHTO LFD 2002 (cur...
Multi-support seismic excitation of long span highway bridges
Gökdemir, Tunç; Askan Gündoğan, Ayşegül; Caner, Alp; Department of Civil Engineering (2017)
Seismic design and analysis are common practices in bridge engineering which require both knowledge and experience. Technical standards, such as CALTRANS (2010) and AASHTO (2007) provide guidance on the analysis with the methods ranging from Response Spectrum Analysis (RSA) to Time History Analysis (THA). These methods are usually sufficient for obtaining the seismic behavior of common structures and capture the dynamic behavior with decent accuracy. However, this may not be the case for structures which sp...
Pedestrian self-reports of factors influencing the use of pedestrian bridges
Rasanen, Mikko; Lajunen, Timo; Alticafarbay, Farahnaz; Aydin, Cumhur (2007-09-01)
The study was designed to find out factors that influence use/non-use of pedestrian bridges. The use rate of five pedestrian bridges was observed in the central business district (CBD) of Ankara. After the observations, a survey was conducted among pedestrians using those bridges and crossing contrary to safe practice under them at street level (n = 408). In the present data, the use rate of pedestrian bridges varied from 6 to 63%. The frequent use of the bridge when crossing the road concerned, and seeing ...
Seismic vulnerability assessment criteria for RC ordinary highway bridges in Turkey
AVŞAR, ÖZGÜR; Yakut, Ahmet (2012-07-10)
One of the most important and challenging steps in seismic vulnerability and performance assessment of highway bridges is the determination of the bridge component damage parameters and their corresponding limit states. These parameters are very essential for defining bridge damage state as well as determining the performance of highway bridges under a seismic event. Therefore, realistic damage limit states are required in the development of reliable fragility curves, which are employed in the seismic risk ...
Bridge rating and reliability correlation: Comprehensive study for different bridge types
Akgül, Ferhat (American Society of Civil Engineers (ASCE), 2004-01-01)
Accumulation of research in the field of bridge evaluation based on structural reliability justifies the consideration of reliability index as the primary measure of safety for bridges. Furthermore, the lifetime bridge evaluation techniques are being mostly based on reliability methods. Currently, bridge safety is measured in terms of the rating factor, which reflects the live load capacity of the structure. In order to investigate the reliability index of an existing bridge and to consider its relation to ...
Citation Formats
B. B. Çakır, “Live load reliability index evaluation for post tensioned balanced cantilever bridges,” M.S. - Master of Science, Middle East Technical University, 2015.