Plastic Joints in Bridge Columns of Atypical Cross-Sections with Smooth Reinforcement without Seismic Details

Abstract

In seismically active areas, knowledge of the actual behavior of bridges under seismic load is extremely important, as they are crucial elements of the transport infrastructure. To assess their seismic resistance, it is necessary to know the key indicators of their seismic response. Bridges built before the adoption of standards for seismic detailing may still contain structural reserves due to the properties of the used materials and construction approach. For example, smooth reinforcement which is found in older bridges due to the material properties, detailing principles, and lower bond strength compared to ribbed reinforcement, allows for greater deformations. In bridges, columns are vital elements employed in the dissipation of seismic energy. Their cross-sections often deviate from the regular square, rectangular, or round cross-sections, which are typically found in building. Based on the behavior of the columns in the vicinity of potential plastic joints, we can determine their deformability. This paper presents an experimental study of seismic resistance indicators around a potential plastic joint for a column with an atypical cross-section, without seismic details and with smooth reinforcement. The experimental results are compared with the numerical and analytical, but also with the experimental results on samples with ribbed reinforcement. Conclusions are made about the behavior of such column elements and their seismic resistance indicators, allowing for the application of an analytical or numerical method with realistic material and element properties and derivation of correction factors due to the effect of the smooth-reinforcement slippage from the anchorage area.

Seismic Assessment and Retrofitting of Existing Road Bridges: State of the Art Review

“…The M–φ curve for each cross-section can be developed analytically or numerically, if sufficient data is available, and subsequently used as an input in the nonlinear analysis. The procedure for the development of M–φ curves for existing RC piers with insufficient ductility is described in [ 6 , 36 ]. M–φ curves can be developed empirically using various scale models in laboratory experiments, as presented in [ 6 , 40 ].…”

“…The procedure for the development of M–φ curves for existing RC piers with insufficient ductility is described in [ 6 , 36 ]. M–φ curves can be developed empirically using various scale models in laboratory experiments, as presented in [ 6 , 40 ].…”

“…If the bridge does not meet the requirements, the evaluation is performed again at the second stage, where nonlinear pushover analysis is used. As the spandrel piers of certain RC arch bridges have non-typical cross-sections, they were assessed using both numerical and experimental approaches with scale models subjected to vertical and horizontal forces in the laboratory [ 6 ].…”

“…This means that it is uneconomical to design bridges that provide a full elastic response to seismic actions. As a solution, the design method takes into account the reduced seismic loads (with a behavioral factor) while focusing on structural detailing to ensure ductile behavior of the bridge system [ 6 ]. While such an approach is justified for the design of new bridges, it is not cost-effective when used in the assessment of existing ones which were designed according to old codes.…”

Assessment of Performance Indicators of a Large-Span Reinforced Concrete Arch Bridge in a Multi-Hazard Environment

“…On the other hand, bridges with large spans or structures of high strategic importance usually have a longer service life and an extended assessment that includes not only a visual inspection but also several in-situ and laboratory tests, structural health monitoring, and optionally, a numerical analysis of the structural assessment, remaining service life and life cycle cost [1]. However, most of the published research papers address only one or a few aspects: e.g., structural assessment of bearing capacity in the combination of numerical analysis and experimental testing [4,5], experimental testing of a specific structural element or detail [6][7][8][9], evaluation and effectiveness of non-destructive testing [3,9,10], analytic models on failure modes [11], and numerical and experimental analysis of the main degradation mechanisms [12][13][14]. A comprehensive assessment of road bridges is included in [1], but in this case, the assessment is based on visual inspection and standard bridges of small and medium spans are analyzed.…”