Seismic performance comparison between force-based and performance-based design as per Canadian Highway Bridge Design Code (CHBDC) 2014 (original) (raw)
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Seismic Performance Comparison Between Force-Based and Performance-Based Design of a Highway Bridge
Canadian Highway Bridge Design Code (CHBDC) 2014 initiated Performance-Based Design (PBD) in Canada. For Lifeline bridges and irregular Major Route bridges, PBD has to be used to explicitly demonstrate structural performance. Regular Major Route bridges can be designed by using FBD or PBD method. In this study, a concrete bent highway bridge is designed by using both FBD and PBD based on CHBDC 2014, and FBD based on CHBDC 2006. Soil-structure interaction is incorporated by using p-y curves in the design and analysis. Dynamic time-history analyses are performed to assess the seismic performance. The assessment is based on the maximum strain limits from CHBDC 2014.
Canadian Journal of Civil Engineering, 2014
Recent research efforts have focused on the development of performance based seismic design methodologies for structures. However, the seismic design rules prescribed in the current Canadian Highway Bridge Design Code (CHBDC) is based largely on force based design principles. Although a set of performance requirements (performance objectives) for different return period earthquake events have been specified, there is no explicit requirement in the CHBDC to check the attainment of such performance objectives for the designed bridges. Also, no engineering parameters have been assigned to the specified performance objectives. This paper correlates seismic performance objectives (both qualitative and quantitative) with engineering parameters, based on the data collected from published experimental investigations and field investigation reports of recent earthquakes. A simple method has been developed and validated with experimental results for assessing the performance of bridges designed according to CHBDC. It has been found that the design rules prescribed in CHBDC do not guarantee that specified multiple seismic performance objectives can be achieved. An implicit seismic design rule in the form of performance response modification factor has been outlined for the performance based seismic design of bridges.
Performance-based seismic design of a continuous bridge
Proceedings of the ICE - Bridge Engineering, 2008
Performance-based design (PBD) provides an insight into the expected performance of a designed structure during an earthquake. Over recent decades, considerable development on the PBD of buildings has taken place, but studies regarding the PBD of bridges are limited. This paper examines the estimated performance of a three-span continuous bridge designed using a codal procedure for the site-specific design response spectrum. A three-dimensional model of the bridge was developed using non-linear modelling of the piers. The response of the bridge was estimated using non-linear static and dynamic procedures. The effect of loading patterns and the accuracy of different pushover analysis methods were examined, and Fema-356 performance levels compared with limit states defined by Kowalsky. The performance of the bridge was studied for different values of the response reduction factor used in the design. The paper also discusses the advantages of PBD and pushover analysis.
Seismic performance-based design of bridges with quantitative local performance criteria
2010
Performance based design of bridges for earthquake resistance is still not explicitly used in design. However, most codes specify a level of performance for bridges under various earthquake inputs. In principle, design rules suggested in the code should meet stipulated performance criteria. However, it has been highlighted in the past that design rules are not directly related with stipulated performance criteria. After the presentation of performance criteria and their relation with post-earthquake functional requirements, the article examines the case of the Canadian Bridge Design Code (CAN/CSA-S6-06). Performance of bridges designed with this code is predicted and compared to expected levels. It is shown that compliance with design rule does not guarantee an adequate performance. This article attempts to correlate qualitative performance criteria with post-earthquake functional requirements, and critically examines code specified design rules and their cost effectiveness. Some im...
Performance-based Seismic Evaluation of Different Concrete Bridges
2019
In this study, analytical fragility curves are developed for the sample concrete bridges of Indian highways to be used in the assessment of their seismic vulnerability. Bridges are first grouped into certain bridge classes based on their structural attributes and sample bridges are generated to account for the structural variability. Nonlinear static analyses and incremental dynamic analyses are conducted for each bridge sample with their detailed 3-D analytical models under different earthquake ground motions having varying seismic intensities. Engineering demand parameters are employed in the determination of seismic response of the bridge components as well as defining damage limit states in terms of member capacities. Fragility curves are obtained from the probability of exceeding each specified damage limit state for each bridge class. Thus, for concrete bridges evaluation of seismic damage is carried out which is most important part to decide seismic vulnerability. Concrete br...
Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015), 2019
This paper focuses on laying the groundwork for risk-targeted performance-based seismic design (PBSD) of Ordinary Standard Bridges (OSBs) in California. Rooted in this formulation is an improved seismic performance assessment methodology that integrates site-specific seismic hazard analysis, structural demand analysis, and damage analysis in a probabilistic framework. At the crux of structural design lies the selection of practicable values of critical design parameters such that predetermined target specifications of performance measures are met. To this end, full-fledged parametric performance assessments of four testbed OSBs are carried out to investigate the effects of varying primary structural design parameters on structural performance. The parametric study indicates erratic levels of conservativeness exhibited by the asdesigned testbed OSBs, thus illustrating the need for a PBSD framework for OSBs such that explicitly stated performance objectives are consistently satisfied. Thus, a simplified, non-traditional, PBSD methodology is distilled out of this work that can be used to: (1) find a design point in a two-dimensional primary design parameter space of a bridge being designed for multiple risk-based performance objectives; and (2) delineate a feasible design domain containing other acceptable design options in the primary design space.
Performance based evaluation of an existing continuous reinforced concrete bridge – a case study
E3S Web of Conferences
A performance-based evaluation was conducted on an eleven-span reinforced concrete bridge located in a high seismicity area. This bridge was designed using SNI 2833:1992 and to be checked using the updated Indonesian seismic hazard map. In addition, a non-linear time history analysis was conducted using eleven pairs of ground motions to evaluate the structural performance of the bridge pier for the anticipated service life. Elastic analysis shows that the existing bridge still satisfies the strength and serviceability requirement despite the increase in seismic demand. Meanwhile, by evaluating the average inelastic longitudinal reinforcement and concrete strain at bridge pier for selected eleven ground motions, this study suggests that the bridge is still “fully operational” and “life safety” when subjected to the lower level (100 year return period) and upper level (1000 year return period) ground motions, respectively.
Seismic Performance Evaluation of a Reinforced Concrete Arch Bridge
Journal of the Institute of Engineering, 2017
The entire Himalayan belt including Nepal area, because of its active tectonic movement, is seismically active causing high risk of earthquake in this region. It is important to evaluate the seismic performance of the structures including bridges to identify to what extent they would survive during earthquake. A reinforced concrete two hinged arch bridge located in Chobhar, Nepal has been selected for the research purpose. This paper presents the determination of seismic performance of a reinforced concrete arch bridge under different ground motions. The seismic input was taken as five different earthquake ground motion histories having different V/H peak ground acceleration ratio for time history analysis. Displacement capacity of the bridge was determined from pushover analysis. Time history analysis was conducted in two different steps: first only horizontal acceleration was applied and next vertical acceleration was applied in addition to horizontal ground motion. Comparisons were made between the responses of the bridge for these two cases. It was found that inclusion of vertical component of ground motion has negligible effect in variation of longitudinal displacement. However, there was remarkable effect in axial force variation. Significant effect in axial force variation in arch rib was observed as V/H ratio increased although the effect in longitudinal displacement with increase in V/H ratio was negligible. Moment demand also increased due to high axial force variation because of vertical ground motion.