Seismic performance of unbonded elastomeric bearings on bridges : an experimental and parametric study

Domaniç, Kemal Arman
Elastomeric bearings were used in a majority of bridges completed in Turkey. Usually, the connection between bearings and the structure were established only by means of friction. Vertical excitation can contribute to a significant damage in such cases, especially at bearing locations, as indeed was the case in the recent 1999 İzmit Earthquake. In Turkish seismic design practice, a common friction coefficient of 0.20 is frequently used. The aim of this study is to look into the values suggested by specifications for friction coefficient between bearings and steel girders through experiments and to explore dynamic and static shear behavior of unbonded bearings. An actual bridge, spanning 12 m with a concrete deck of 3.5 m width over 3 steel I-girders is constructed on a shake table with a hydraulic actuator capable of delivering a user supplied displacement history. Bearing responses under seismic loadings were measured. Due to a very high friction coefficient, bonded and unbonded bearings exhibited similar seismic performance. Results of shake table and static friction tests performed on unbonded bearings indicated that use of a friction coefficient of 0.20 in seismic analysis can be unconservatively low to determine substructure forces and may significantly overestimate seismic displacement demands. Such low values should not be used in seismic design unless indicated otherwise by test data. A comprehensive parametric study was performed and a conservative trendline of deck displacements as a function of acceleration coefficients is presented with a procedure to estimate maximum bearing shear forces for the investigated cases.


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...
Calibration of Turkish LRFD bridge design method for slab on steel plate girders
Koç, Ahmet Fatih; Caner, Alp; Department of Civil Engineering (2013)
Steel composite I-girder bridges are usually used to span between 50 to 80 meters in Turkey. In a typical Turkish bridge design, a modified version of the AASHTO LFD (Load Factor Design) or ASD (Allowable Stress Design) requirements are used until now. The recent switch of the US bridge codes to LRFD method also necessitates the calibration of the new design of the Turkish bridges according to the LRFD system. The main aim of this study is to define a new type of live (truck) load to be used in the basic gr...
Caner, Alp; Shaban, Nefize (null; 2017-01-05)
A standard highway bridge has usually multi simple spans supported over piers by elastomeric bearings in Turkey. The bearings usually do not provide a positive connection but in contact with girder and pier by only gravitational forces. In this study, a model test bridge of about ½ scale have been shaken under low to moderate earth quakes to determine the change in response of the bridge with different seismic isolation configurations. Three configurations of bearings are elastomeric bearings, lead core bea...
Scour and scour protection at bridge abutments
Kayatürk, Şerife Yurdagül; Göğüş, Mustafa; Department of Civil Engineering (2005)
Bridge failures are mainly caused by scouring the bed material around bridge foundations during flood. In this study, scour phenomenon around bridge abutments is experimentally studied. Effect of abutment size, location and size of the collars placed around the abutments, time evaluation of scour hole around the abutment, scour characteristics of abutment and pier interaction were experimentally investigated. Scour measurements were conducted in a rectangular channel of 30 m long and 1.5 m wide filled with ...
The Assessment of seismic performance of multi-span highway bridges in Turkey including column deterioration
Ocak, Canan Elif; Caner, Alp; Department of Civil Engineering (2016)
Considering the latest three major earthquakes occurred in Turkey, the performance of the bridges could be evaluated as successful. Bridges are one of the most important members of transportation network and it is important for them to survive during earthquakes. Contrary to the general belief, minimum damage during earthquakes mean very high safety factors included to the design rather than a success. Up to now, the bridges designed in Turkey are based on AASHTO (American Association of State Highway and T...
Citation Formats
K. A. Domaniç, “Seismic performance of unbonded elastomeric bearings on bridges : an experimental and parametric study,” Ph.D. - Doctoral Program, Middle East Technical University, 2015.