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Nonlinear time history analyses of structures require full time series of ground motion records. For regions with sparse seismic networks or potential large earthquakes, ground motion simulation has gained more attention in recent years. Simulated records are required to be generated using regional input dataset and then verified against existing recorded ground motions of past events. To use simulated ground motions in engineering applications, estimation of reliable seismic demand parameters is essential. In this study, the real and simulated records of the 2009 L’Aquila, Italy earthquake with (Mw=6.3) are investigated for their use in engineering practice. In the first step, misfits are evaluated for alternative seismological measures (peak values, duration and frequency as well as energy content of the time histories). Next, varying multi-degree-of-freedom reinforced concrete structures with different number of stories are selected. Numerical models of the structures are performed in the OpenSees platform. Seismic performance measures in terms of inter-story drift ratio for the selected structures are assessed through nonlinear time history analyses for both the real and simulated ground motions. Then, the misfits are estimated in terms of structural demand parameters. Results reveal a good fit between the seismological and engineering demand misfits for the selected ground motion simulation approaches.

A comprehensive study has been carried out to investigate the correlation between maximum interstory drift demand of frame structures and a number of widely used ground motion intensity parameters. Nonlinear time-history analyses of 16 reinforced concrete frames were performed under a set of 80 ground motion records. The frames were selected to represent features of typical low- to mid-rise reinforced concrete structures. The records contained in the ground motion database were compiled from recorded ground motions with the intention to represent a wide range of seismic forces that impose various degrees of elastic as well as inelastic response of the frames. The maximum interstory drift ratios computed were compared with the ground motion intensity parameters employed and correlations between them were investigated through coefficients of correlation and determination. The results revealed that spectrum intensity parameters, having the strongest correlation, are superior to other parameters such as peak ground velocity, peak ground acceleration, and spectral acceleration. CE Database subject headings: Ground motion; Seismic analysis; Damage; Reinforced concrete; Framed structures.

Safety of a highway infrastructure system depends very much on the proper maintenance of bridges. The level of required maintenance is, typically, determined through a series of regular field inspections with the guidance of safety-economy trade-off. In Turkey, bridge maintenance, repair, and rehabilitation are currently performed on an as-needed basis. Time-dependent reliability analysis cannot be utilized for Turkish bridges for the time being since the majority of the bridges are either not regularly inspected or not inspected at all. The purpose of this paper is to propose a simple method to assess the remaining service life of a bridge by defining a relationship between its current condition rating and its age by evaluating a set of bridges at different ages. In a case study, 28 bridges were inspected for the first time to assess the average life expectancy. The average life of a bridge was predicted to be 80 years, and for this set of bridges, the main body components were found to deteriorate more than earth retaining and serviceability components. DOI: 10.1061/(ASCE)0887-3828(2008)22:2(108) CE Database subject headings: Bridges, highway; Deterioration; Inspection; Concrete; Steel; Service life; Serviceability.

A detailed seismic performance assessment procedure has been developed for reinforced concrete (RC) frame buildings with masonry infill walls. The procedure is based on member damage functions, in terms of interstory drift ratios. These functions are developed for the primary components, namely, columns, beams, and infill walls. For developing these functions, analytical investigations to determine the influence of several parameters on the damageability of components were combined with experimental data. A new approach has been developed to synthesize component damage states to determine the story and eventually the building level performance states. The procedure has been calibrated and compared with other procedures by predicting the observed performance of three buildings exposed to recent earthquakes in Turkey. It is concluded that the developed procedure can satisfactorily predict the damage experienced by most of the components of the studied buildings. Moreover, the procedure reasonably captured the observed building damage states. Accordingly, the developed procedure can be used for a reliable performance assessment as well as performance-based design of RC frame structures. DOI: 10.1061/(ASCE)0733-9445(2007)133:4(576) CE Database subject headings: Damage; Assessment; Concrete, reinforced; Structural members; Deformation; Seismic analysis; Framed structures.

Recent studies on elastomeric bearings led to changes in the design specifications, which tend to indicate that bearings fabricated in the past, would fail the current test requirements. This is contrary to the fact that there have been no reported problems of poor bearing performance in low-temperature regions. AASHTO requires low-temperature tests to determine the change in the shear modulus, which is limited to a certain value. This criterion does not adequately address the performance of the bearings, because in-service conditions of an elastomeric bearing are not sufficiently taken into account. The field performance of the bearings depends primarily on the temperature characteristics of the geographic location where the bearing is installed, which also determines the probable amplitude of shear strain the bearing would experience. Thus, to adequately evaluate the in-service performance of the bearings, a performance-based procedure should be employed. In this paper, a variety of bearings were tested and checked at four different low-temperature locations. The test results have been reported in a companion paper. It was established that most of the bearings could in fact serve satisfactorily in spite of the fact that the bearings in many instances fail the current test procedures. This indicates that the current testing requirements related to cold-temperature performance are too severe. Hence, a procedure that relies on the historic temperature records of the region where the bearing would be installed is recommended to determine the performance requirements at a particular location. In this procedure, the acceptance criterion is based on the maximum expected shear force and the potential slip of the bearings. DOI: 10.1061/(ASCE)0733-9445(2002)128:8(995) CE Database keywords: Elastomer; Bearing capacity; Temperature; Bridges; Shear modulus; Stiffening.

Experimental research was conducted to investigate the performance of elastomeric bridge bearings at low temperatures. Full-size natural rubber and neoprene bearings were tested by specially designed test setups inside a walk-in-type environmental chamber. Steel laminated bearings were ordered with two specified shear modulus, 0.69 and 1.08 MPa. Tests were conducted at 23, -10, -20, and -30[degrees]C for a period of 21 days. The effect of cyclic compression, cyclic shear, rate of loading, type of elastomer compound, temperature history, creep, and slip coefficient on the performance was investigated. Approximately 500 shear stiffness tests were performed. Results indicated that the increase in shear stiffness at low temperature is a function of elastomer compound, temperature, and time. In addition, rate of loading, amplitude of strain, coefficient of friction, and temperature history were identified as important parameters that influence the bearing performance. Creep behavior at low temperature was significantly different from creep at room temperature but had no significant influence on the overall performance. It was shown that cyclic compression force and cyclic shear strain do not have significant influence on time-dependent stiffening (crystallization) of bearings. The results of this paper were used to develop a performance-based evaluation and acceptance criterion that is presented in a companion paper. DOI: 10.1061/(ASCE)0733-9445(2002)128:8(986) CE Database keywords: Bridges; Cyclic loads; Temperature; Elastomer; Shear modulus.